Abstract

The terahertz (THz) frequency quantum cascade laser (QCL) is a compact source of high-power radiation with a narrow intrinsic linewidth. As such, THz QCLs are extremely promising sources for applications including high-resolution spectroscopy, heterodyne detection, and coherent imaging. We exploit the remarkable phase-stability of THz QCLs to create a coherent swept-frequency delayed self-homodyning method for both imaging and materials analysis, using laser feedback interferometry. Using our scheme we obtain amplitude-like and phase-like images with minimal signal processing. We determine the physical relationship between the operating parameters of the laser under feedback and the complex refractive index of the target and demonstrate that this coherent detection method enables extraction of complex refractive indices with high accuracy. This establishes an ultimately compact and easy-to-implement THz imaging and materials analysis system, in which the local oscillator, mixer, and detector are all combined into a single laser.

© 2013 OSA

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  1. B. Hu and M. Nuss, “Imaging with terahertz waves,” Opt. Lett.20, 1716–1718 (1995).
    [CrossRef] [PubMed]
  2. W. L. Chan, J. Deibel, and D. M. Mittleman, “Imaging with terahertz radiation,” Rep. Prog. Phys.70, 1325 (2007).
    [CrossRef]
  3. A. G. Davies, A. D. Burnett, W. Fan, E. H. Linfield, and J. E. Cunningham, “Terahertz spectroscopy of explosives and drugs,” Mater. Today11, 18–26 (2008).
    [CrossRef]
  4. P. U. Jepsen, D. G. Cooke, and M. Koch, “Terahertz spectroscopy and imaging — Modern techniques and applications,” Laser Photon. Rev.5, 124–166 (2011).
    [CrossRef]
  5. M. Tonouchi, “Cutting-edge terahertz technology,” Nature Photon.1, 97–105 (2007).
    [CrossRef]
  6. H. Shimosato, M. Ashida, T. Itoh, S. Saito, and K. Sakai, “Ultrabroadband detection of terahertz radiation from 0.1 to 100 THz with photoconductive antenna,” in “Ultrafast Optics V,” (Springer, 2007), pp. 317–323.
    [CrossRef]
  7. P. Han, M. Tani, M. Usami, S. Kono, R. Kersting, and X.-C. Zhang, “A direct comparison between terahertz time-domain spectroscopy and far-infrared fourier transform spectroscopy,” J. Appl. Phys.89, 2357–2359 (2001).
    [CrossRef]
  8. M. Naftaly, “Metrology issues and solutions in THz time-domain spectroscopy: Noise, errors, calibration,” IEEE Sens. J.13, 8–17 (2013).
    [CrossRef]
  9. W. H. Fan, A. Burnett, P. C. Upadhya, J. Cunningham, E. H. Linfield, and A. G. Davies, “Far-infrared spectroscopic characterization of explosives for security applications using broadband terahertz time-domain spectroscopy,” Appl. Spectrosc.61, 638–643 (2007).
    [CrossRef] [PubMed]
  10. X. Lu, N. Karpowicz, Y. Chen, and X.-C. Zhang, “Systematic study of broadband terahertz gas sensor,” Appl. Phys. Lett.93, 261106 (2008).
    [CrossRef]
  11. X. Zheng, C. V. McLaughlin, P. Cunningham, and L. M. Hayden, “Organic broadband terahertz sources and sensors,” J. Nanoelectron. Optoelectron.2, 58–76 (2007).
    [CrossRef]
  12. C. V. McLaughlin, L. M. Hayden, B. Polishak, S. Huang, J. Luo, T.-D. Kim, and A. K.-Y. Jen, “Wideband 15 THz response using organic electro-optic polymer emitter-sensor pairs at telecommunication wavelengths,” Appl. Phys. Lett.92, 151107 (2008).
    [CrossRef]
  13. L. Duvillaret, F. Garet, and J.-L. Coutaz, “A reliable method for extraction of material parameters in terahertz time-domain spectroscopy,” IEEE J. Sel. Top. Quantum Electron.2, 739–746 (1996).
    [CrossRef]
  14. N. Laman, S. S. Harsha, D. Grischkowsky, and J. S. Melinger, “7 GHz resolution waveguide THz spectroscopy of explosives related solids showing new features,” Opt. Express16, 4094–4105 (2008).
    [CrossRef] [PubMed]
  15. R. Köhler, A. Tredicucci, F. Beltram, H. E. Beere, E. H. Linfield, A. G. Davies, D. A. Ritchie, R. C. Iotti, and F. Rossi, “Terahertz semiconductor-heterostructure laser,” Nature417, 156–159 (2002).
    [CrossRef] [PubMed]
  16. M. S. Vitiello, L. Consolino, S. Bartalini, A. Taschin, A. Tredicucci, M. Inguscio, and P. De Natale, “Quantum-limited frequency fluctuations in a terahertz laser,” Nat. Photonics6, 525–528 (2012).
    [CrossRef]
  17. J. Darmo, V. Tamosiunas, G. Fasching, J. Kröll, K. Unterrainer, M. Beck, M. Giovannini, J. Faist, C. Kremser, and P. Debbage, “Imaging with a Terahertz quantum cascade laser,” Opt. Express12, 1879–1884 (2004).
    [CrossRef] [PubMed]
  18. A. W. Lee, Q. Qin, S. Kumar, B. S. Williams, Q. Hu, and J. L. Reno, “Real-time terahertz imaging over a standoff distance (≫25 meters),” Appl. Phys. Lett.89, 141125–141125 (2006).
    [CrossRef]
  19. P. Dean, M. U. Shaukat, S. P. Khanna, S. Chakraborty, M. Lachab, A. Burnett, G. Davies, and E. H. Linfield, “Absorption-sensitive diffuse reflection imaging of concealed powders using a terahertz quantum cascade laser,” Opt. Express16, 5997–6007 (2008).
    [CrossRef] [PubMed]
  20. P. Dean, N. K. Saat, S. P. Khanna, M. Salih, A. Burnett, J. Cunningham, E. H. Linfield, and A. G. Davies, “Dual-frequency imaging using an electrically tunable terahertz quantum cascade laser,” Opt. Express17, 20631–20641 (2009).
    [CrossRef] [PubMed]
  21. H.-W. Hubers, S. Pavlov, H. Richter, A. Semenov, L. Mahler, A. Tredicucci, H. Beere, and D. Ritchie, “High-resolution gas phase spectroscopy with a distributed feedback terahertz quantum cascade laser,” Appl. Phys. Lett.89, 061115 (2006).
    [CrossRef]
  22. A. A. Danylov, T. M. Goyette, J. Waldman, M. J. Coulombe, A. J. Gatesman, R. H. Giles, X. Qian, N. Chandrayan, S. Vangala, K. Termkoa, W. D. Goodhue, and W. E. Nixon, “Terahertz inverse synthetic aperture radar (ISAR) imaging with a quantum cascade laser transmitter,” Opt. Express18, 16264–16272 (2010).
    [CrossRef] [PubMed]
  23. M. Ravaro, V. Jagtap, G. Santarelli, C. Sirtori, L. Li, S. Khanna, E. Linfield, and S. Barbieri, “Continuous-wave coherent imaging with terahertz quantum cascade lasers using electro-optic harmonic sampling,” Appl. Phys. Lett.102, 091107 (2013).
    [CrossRef]
  24. S. Barbieri, P. Gellie, G. Santarelli, L. Ding, W. Maineult, C. Sirtori, R. Colombelli, H. Beere, and D. Ritchie, “Phase-locking of a 2.7-THz quantum cascade laser to a mode-locked erbium-doped fibre laser,” Nature Photon.4, 636–640 (2010).
    [CrossRef]
  25. M. Ravaro, S. Barbieri, G. Santarelli, V. Jagtap, C. Manquest, C. Sirtori, S. Khanna, and E. Linfield, “Measurement of the intrinsic linewidth of terahertz quantum cascade lasers using a near-infrared frequency comb,” Opt. Express20, 25654–25661 (2012).
    [CrossRef] [PubMed]
  26. R. P. Green, J. H. Xu, L. Mahler, A. Tredicucci, F. Beltram, G. Giuliani, H. E. Beere, and D. A. Ritchie, “Linewidth enhancement factor of terahertz quantum cascade lasers,” Appl. Phys. Lett.92, 071106 (2008).
    [CrossRef]
  27. Y. L. Lim, P. Dean, M. Nikolić, R. Kliese, S. P. Khanna, M. Lachab, A. Valavanis, D. Indjin, Z. Ikonić, P. Harrison, E. H. Linfield, A. G. Davies, S. J. Wilson, and A. D. Rakić, “Demonstration of a self-mixing displacement sensor based on terahertz quantum cascade lasers,” Appl. Phys. Lett.99, 081108 (2011).
    [CrossRef]
  28. P. Dean, Y. L. Lim, A. Valavanis, R. Kliese, M. Nikolić, S. P. Khanna, M. Lachab, D. Indjin, Z. Ikonić, P. Harrison, A. D. Rakić, E. H. Linfield, and A. G. Davies, “Terahertz imaging through self-mixing in a quantum cascade laser,” Opt. Lett.36, 2587–2589 (2011).
    [CrossRef] [PubMed]
  29. S. Donati, “Developing self-mixing interferometry for instrumentation and measurements,” Laser Photon. Rev.6, 393–417 (2012).
    [CrossRef]
  30. T. Bosch, C. Bès, L. Scalise, and G. Plantier, Encyclopedia of Sensors (American Scientific Publishers, 2006), chap. Optical feedback interferometry, pp. 1–20.
  31. G. Giuliani, M. Norgia, S. Donati, and T. Bosch, “Laser diode self-mixing technique for sensing applications,” J. Opt. A: Pure Appl. Opt.4, S283–S294 (2002).
    [CrossRef]
  32. G. Giuliani and S. Donati, Unlocking Dynamical Diversity: Optical Feedback Effects on Semiconductor Lasers (John Wiley & Sons, 2005), chap. 7: Laser Interferometry.
  33. G. Scalari, L. Ajili, J. Faist, H. Beere, E. Linfield, D. Ritchie, and G. Davies, “Far-infrared (λ= 87 μm) bound-to-continuum quantum-cascade lasers operating up to 90 K,” Appl. Phys. Lett.82, 3165–3167 (2003).
    [CrossRef]
  34. D. Indjin, P. Harrison, R. Kelsall, and Z. Ikonić, “Mechanisms of temperature performance degradation in terahertz quantum-cascade lasers,” Appl. Phys. Lett.82, 1347–1349 (2003).
    [CrossRef]
  35. P. Gellie, S. Barbieri, J.-F. Lampin, P. Filloux, C. Manquest, C. Sirtori, I. Sagnes, S. P. Khanna, E. H. Linfield, A. G. Davies, H. Beere, and D. Ritchie, “Injection-locking of terahertz quantum cascade lasers up to 35 GHz using RF amplitude modulation,” Opt. Express18, 20799–20816 (2010).
    [CrossRef] [PubMed]
  36. S. Barbieri, M. Ravaro, P. Gellie, G. Santarelli, C. Manquest, C. Sirtori, S. P. Khanna, E. H. Linfield, and A. G. Davies, “Coherent sampling of active mode-locked terahertz quantum cascade lasers and frequency synthesis,” Nature Photon.5, 306–313 (2011).
    [CrossRef]
  37. K. Petermann, Laser diode modulation and noise, 3rd ed. (Springer, 1991).
  38. R. Lang and K. Kobayashi, “External optical feedback effects on semiconductor injection laser properties,” IEEE J. Quantum Electron.16, 347–355 (1980).
    [CrossRef]
  39. P. Spencer, P. Rees, and I. Pierce, Unlocking Dynamical Diversity: Optical Feedback Effects on Semiconductor Lasers (John Wiley & Sons, 2005), chap. 2: Theoretical Analysis.
  40. S. Donati, “Responsivity and noise of self-mixing photodetection schemes,” IEEE J. Quantum Electron.47, 1428–1433 (2011).
    [CrossRef]
  41. G. Plantier, C. Bès, and T. Bosch, “Behavioral model of a self-mixing laser diode sensor,” IEEE J. Quantum Electron.41, 1157–1167 (2005).
    [CrossRef]
  42. Y. L. Lim, K. Bertling, P. Rio, J. Tucker, and A. Rakic, “Displacement and distance measurement using the change in junction voltage across a laser diode due to the self-mixing effect,” in Photonics: Design, Technology, and Packaging II, D. Abbott, Y. S. Kivshar, H. H. Rubinsztein-Dunlop, and S. Fan, eds., Proc. SPIE 6038, 60381O-1 (2006).
  43. G. Bryant, Principles of microwave measurements(P. Peregrinus Ltd. on behalf of the Institution of Electrical Engineers, 1993).
    [CrossRef]
  44. P. Cunningham, N. Valdes, F. Vallejo, L. Hayden, B. Polishak, X. Zhou, J. Luo, A. Jen, J. Williams, and R. Twieg, “Broadband terahertz characterization of the refractive index and absorption of some important polymeric and organic electro-optic materials,” J. Appl. Phys.109, 043505–043505 (2011).
    [CrossRef]
  45. Y.-S. Jin, G.-J. Kim, and S.-G. Jeon, “Terahertz dielectric properties of polymers,” J. Korean Phys. Soc.49, 513–517 (2006).
  46. S. Wietzke, C. Jansen, M. Reuter, T. Jung, D. Kraft, S. Chatterjee, B. Fischer, and M. Koch, “Terahertz spectroscopy on polymers: A review of morphological studies,” J. Mol. Struct.1006, 41–51 (2011).
    [CrossRef]
  47. A. W. M. Lee, T.-Y. Kao, D. Burghoff, Q. Hu, and J. L. Reno, “Terahertz tomography using quantum-cascade lasers,” Opt. Lett.37, 217–219 (2012).
    [CrossRef] [PubMed]
  48. S. Barbieri, J. Alton, H. E. Beere, J. Fowler, E. H. Linfield, and D. A. Ritchie, “2.9 THz quantum cascade lasers operating up to 70 K in continuous wave,” Appl. Phys. Lett.85, 1674 (2004).
    [CrossRef]
  49. S. P. Khanna, S. Chakraborty, M. Lachab, N. M. Hinchcliffe, E. H. Linfield, and A. G. Davies, “The growth and measurement of terahertz quantum cascade lasers,” Physica E: Low Dimens. Syst. Nanostruct.40, 1859–1861 (2008).
    [CrossRef]
  50. A. D. Rakić, “Algorithm for the determination of intrinsic optical constants of metal films: application to aluminum,” Appl. Opt.34, 4755–4767 (1995).
    [CrossRef]

2013 (2)

M. Naftaly, “Metrology issues and solutions in THz time-domain spectroscopy: Noise, errors, calibration,” IEEE Sens. J.13, 8–17 (2013).
[CrossRef]

M. Ravaro, V. Jagtap, G. Santarelli, C. Sirtori, L. Li, S. Khanna, E. Linfield, and S. Barbieri, “Continuous-wave coherent imaging with terahertz quantum cascade lasers using electro-optic harmonic sampling,” Appl. Phys. Lett.102, 091107 (2013).
[CrossRef]

2012 (4)

M. S. Vitiello, L. Consolino, S. Bartalini, A. Taschin, A. Tredicucci, M. Inguscio, and P. De Natale, “Quantum-limited frequency fluctuations in a terahertz laser,” Nat. Photonics6, 525–528 (2012).
[CrossRef]

S. Donati, “Developing self-mixing interferometry for instrumentation and measurements,” Laser Photon. Rev.6, 393–417 (2012).
[CrossRef]

A. W. M. Lee, T.-Y. Kao, D. Burghoff, Q. Hu, and J. L. Reno, “Terahertz tomography using quantum-cascade lasers,” Opt. Lett.37, 217–219 (2012).
[CrossRef] [PubMed]

M. Ravaro, S. Barbieri, G. Santarelli, V. Jagtap, C. Manquest, C. Sirtori, S. Khanna, and E. Linfield, “Measurement of the intrinsic linewidth of terahertz quantum cascade lasers using a near-infrared frequency comb,” Opt. Express20, 25654–25661 (2012).
[CrossRef] [PubMed]

2011 (7)

P. Dean, Y. L. Lim, A. Valavanis, R. Kliese, M. Nikolić, S. P. Khanna, M. Lachab, D. Indjin, Z. Ikonić, P. Harrison, A. D. Rakić, E. H. Linfield, and A. G. Davies, “Terahertz imaging through self-mixing in a quantum cascade laser,” Opt. Lett.36, 2587–2589 (2011).
[CrossRef] [PubMed]

P. Cunningham, N. Valdes, F. Vallejo, L. Hayden, B. Polishak, X. Zhou, J. Luo, A. Jen, J. Williams, and R. Twieg, “Broadband terahertz characterization of the refractive index and absorption of some important polymeric and organic electro-optic materials,” J. Appl. Phys.109, 043505–043505 (2011).
[CrossRef]

S. Wietzke, C. Jansen, M. Reuter, T. Jung, D. Kraft, S. Chatterjee, B. Fischer, and M. Koch, “Terahertz spectroscopy on polymers: A review of morphological studies,” J. Mol. Struct.1006, 41–51 (2011).
[CrossRef]

Y. L. Lim, P. Dean, M. Nikolić, R. Kliese, S. P. Khanna, M. Lachab, A. Valavanis, D. Indjin, Z. Ikonić, P. Harrison, E. H. Linfield, A. G. Davies, S. J. Wilson, and A. D. Rakić, “Demonstration of a self-mixing displacement sensor based on terahertz quantum cascade lasers,” Appl. Phys. Lett.99, 081108 (2011).
[CrossRef]

S. Barbieri, M. Ravaro, P. Gellie, G. Santarelli, C. Manquest, C. Sirtori, S. P. Khanna, E. H. Linfield, and A. G. Davies, “Coherent sampling of active mode-locked terahertz quantum cascade lasers and frequency synthesis,” Nature Photon.5, 306–313 (2011).
[CrossRef]

S. Donati, “Responsivity and noise of self-mixing photodetection schemes,” IEEE J. Quantum Electron.47, 1428–1433 (2011).
[CrossRef]

P. U. Jepsen, D. G. Cooke, and M. Koch, “Terahertz spectroscopy and imaging — Modern techniques and applications,” Laser Photon. Rev.5, 124–166 (2011).
[CrossRef]

2010 (3)

2009 (1)

2008 (7)

A. G. Davies, A. D. Burnett, W. Fan, E. H. Linfield, and J. E. Cunningham, “Terahertz spectroscopy of explosives and drugs,” Mater. Today11, 18–26 (2008).
[CrossRef]

X. Lu, N. Karpowicz, Y. Chen, and X.-C. Zhang, “Systematic study of broadband terahertz gas sensor,” Appl. Phys. Lett.93, 261106 (2008).
[CrossRef]

C. V. McLaughlin, L. M. Hayden, B. Polishak, S. Huang, J. Luo, T.-D. Kim, and A. K.-Y. Jen, “Wideband 15 THz response using organic electro-optic polymer emitter-sensor pairs at telecommunication wavelengths,” Appl. Phys. Lett.92, 151107 (2008).
[CrossRef]

S. P. Khanna, S. Chakraborty, M. Lachab, N. M. Hinchcliffe, E. H. Linfield, and A. G. Davies, “The growth and measurement of terahertz quantum cascade lasers,” Physica E: Low Dimens. Syst. Nanostruct.40, 1859–1861 (2008).
[CrossRef]

R. P. Green, J. H. Xu, L. Mahler, A. Tredicucci, F. Beltram, G. Giuliani, H. E. Beere, and D. A. Ritchie, “Linewidth enhancement factor of terahertz quantum cascade lasers,” Appl. Phys. Lett.92, 071106 (2008).
[CrossRef]

N. Laman, S. S. Harsha, D. Grischkowsky, and J. S. Melinger, “7 GHz resolution waveguide THz spectroscopy of explosives related solids showing new features,” Opt. Express16, 4094–4105 (2008).
[CrossRef] [PubMed]

P. Dean, M. U. Shaukat, S. P. Khanna, S. Chakraborty, M. Lachab, A. Burnett, G. Davies, and E. H. Linfield, “Absorption-sensitive diffuse reflection imaging of concealed powders using a terahertz quantum cascade laser,” Opt. Express16, 5997–6007 (2008).
[CrossRef] [PubMed]

2007 (4)

X. Zheng, C. V. McLaughlin, P. Cunningham, and L. M. Hayden, “Organic broadband terahertz sources and sensors,” J. Nanoelectron. Optoelectron.2, 58–76 (2007).
[CrossRef]

W. L. Chan, J. Deibel, and D. M. Mittleman, “Imaging with terahertz radiation,” Rep. Prog. Phys.70, 1325 (2007).
[CrossRef]

M. Tonouchi, “Cutting-edge terahertz technology,” Nature Photon.1, 97–105 (2007).
[CrossRef]

W. H. Fan, A. Burnett, P. C. Upadhya, J. Cunningham, E. H. Linfield, and A. G. Davies, “Far-infrared spectroscopic characterization of explosives for security applications using broadband terahertz time-domain spectroscopy,” Appl. Spectrosc.61, 638–643 (2007).
[CrossRef] [PubMed]

2006 (3)

A. W. Lee, Q. Qin, S. Kumar, B. S. Williams, Q. Hu, and J. L. Reno, “Real-time terahertz imaging over a standoff distance (≫25 meters),” Appl. Phys. Lett.89, 141125–141125 (2006).
[CrossRef]

H.-W. Hubers, S. Pavlov, H. Richter, A. Semenov, L. Mahler, A. Tredicucci, H. Beere, and D. Ritchie, “High-resolution gas phase spectroscopy with a distributed feedback terahertz quantum cascade laser,” Appl. Phys. Lett.89, 061115 (2006).
[CrossRef]

Y.-S. Jin, G.-J. Kim, and S.-G. Jeon, “Terahertz dielectric properties of polymers,” J. Korean Phys. Soc.49, 513–517 (2006).

2005 (1)

G. Plantier, C. Bès, and T. Bosch, “Behavioral model of a self-mixing laser diode sensor,” IEEE J. Quantum Electron.41, 1157–1167 (2005).
[CrossRef]

2004 (2)

J. Darmo, V. Tamosiunas, G. Fasching, J. Kröll, K. Unterrainer, M. Beck, M. Giovannini, J. Faist, C. Kremser, and P. Debbage, “Imaging with a Terahertz quantum cascade laser,” Opt. Express12, 1879–1884 (2004).
[CrossRef] [PubMed]

S. Barbieri, J. Alton, H. E. Beere, J. Fowler, E. H. Linfield, and D. A. Ritchie, “2.9 THz quantum cascade lasers operating up to 70 K in continuous wave,” Appl. Phys. Lett.85, 1674 (2004).
[CrossRef]

2003 (2)

G. Scalari, L. Ajili, J. Faist, H. Beere, E. Linfield, D. Ritchie, and G. Davies, “Far-infrared (λ= 87 μm) bound-to-continuum quantum-cascade lasers operating up to 90 K,” Appl. Phys. Lett.82, 3165–3167 (2003).
[CrossRef]

D. Indjin, P. Harrison, R. Kelsall, and Z. Ikonić, “Mechanisms of temperature performance degradation in terahertz quantum-cascade lasers,” Appl. Phys. Lett.82, 1347–1349 (2003).
[CrossRef]

2002 (2)

G. Giuliani, M. Norgia, S. Donati, and T. Bosch, “Laser diode self-mixing technique for sensing applications,” J. Opt. A: Pure Appl. Opt.4, S283–S294 (2002).
[CrossRef]

R. Köhler, A. Tredicucci, F. Beltram, H. E. Beere, E. H. Linfield, A. G. Davies, D. A. Ritchie, R. C. Iotti, and F. Rossi, “Terahertz semiconductor-heterostructure laser,” Nature417, 156–159 (2002).
[CrossRef] [PubMed]

2001 (1)

P. Han, M. Tani, M. Usami, S. Kono, R. Kersting, and X.-C. Zhang, “A direct comparison between terahertz time-domain spectroscopy and far-infrared fourier transform spectroscopy,” J. Appl. Phys.89, 2357–2359 (2001).
[CrossRef]

1996 (1)

L. Duvillaret, F. Garet, and J.-L. Coutaz, “A reliable method for extraction of material parameters in terahertz time-domain spectroscopy,” IEEE J. Sel. Top. Quantum Electron.2, 739–746 (1996).
[CrossRef]

1995 (2)

1980 (1)

R. Lang and K. Kobayashi, “External optical feedback effects on semiconductor injection laser properties,” IEEE J. Quantum Electron.16, 347–355 (1980).
[CrossRef]

Ajili, L.

G. Scalari, L. Ajili, J. Faist, H. Beere, E. Linfield, D. Ritchie, and G. Davies, “Far-infrared (λ= 87 μm) bound-to-continuum quantum-cascade lasers operating up to 90 K,” Appl. Phys. Lett.82, 3165–3167 (2003).
[CrossRef]

Alton, J.

S. Barbieri, J. Alton, H. E. Beere, J. Fowler, E. H. Linfield, and D. A. Ritchie, “2.9 THz quantum cascade lasers operating up to 70 K in continuous wave,” Appl. Phys. Lett.85, 1674 (2004).
[CrossRef]

Ashida, M.

H. Shimosato, M. Ashida, T. Itoh, S. Saito, and K. Sakai, “Ultrabroadband detection of terahertz radiation from 0.1 to 100 THz with photoconductive antenna,” in “Ultrafast Optics V,” (Springer, 2007), pp. 317–323.
[CrossRef]

Barbieri, S.

M. Ravaro, V. Jagtap, G. Santarelli, C. Sirtori, L. Li, S. Khanna, E. Linfield, and S. Barbieri, “Continuous-wave coherent imaging with terahertz quantum cascade lasers using electro-optic harmonic sampling,” Appl. Phys. Lett.102, 091107 (2013).
[CrossRef]

M. Ravaro, S. Barbieri, G. Santarelli, V. Jagtap, C. Manquest, C. Sirtori, S. Khanna, and E. Linfield, “Measurement of the intrinsic linewidth of terahertz quantum cascade lasers using a near-infrared frequency comb,” Opt. Express20, 25654–25661 (2012).
[CrossRef] [PubMed]

S. Barbieri, M. Ravaro, P. Gellie, G. Santarelli, C. Manquest, C. Sirtori, S. P. Khanna, E. H. Linfield, and A. G. Davies, “Coherent sampling of active mode-locked terahertz quantum cascade lasers and frequency synthesis,” Nature Photon.5, 306–313 (2011).
[CrossRef]

P. Gellie, S. Barbieri, J.-F. Lampin, P. Filloux, C. Manquest, C. Sirtori, I. Sagnes, S. P. Khanna, E. H. Linfield, A. G. Davies, H. Beere, and D. Ritchie, “Injection-locking of terahertz quantum cascade lasers up to 35 GHz using RF amplitude modulation,” Opt. Express18, 20799–20816 (2010).
[CrossRef] [PubMed]

S. Barbieri, P. Gellie, G. Santarelli, L. Ding, W. Maineult, C. Sirtori, R. Colombelli, H. Beere, and D. Ritchie, “Phase-locking of a 2.7-THz quantum cascade laser to a mode-locked erbium-doped fibre laser,” Nature Photon.4, 636–640 (2010).
[CrossRef]

S. Barbieri, J. Alton, H. E. Beere, J. Fowler, E. H. Linfield, and D. A. Ritchie, “2.9 THz quantum cascade lasers operating up to 70 K in continuous wave,” Appl. Phys. Lett.85, 1674 (2004).
[CrossRef]

Bartalini, S.

M. S. Vitiello, L. Consolino, S. Bartalini, A. Taschin, A. Tredicucci, M. Inguscio, and P. De Natale, “Quantum-limited frequency fluctuations in a terahertz laser,” Nat. Photonics6, 525–528 (2012).
[CrossRef]

Beck, M.

Beere, H.

S. Barbieri, P. Gellie, G. Santarelli, L. Ding, W. Maineult, C. Sirtori, R. Colombelli, H. Beere, and D. Ritchie, “Phase-locking of a 2.7-THz quantum cascade laser to a mode-locked erbium-doped fibre laser,” Nature Photon.4, 636–640 (2010).
[CrossRef]

P. Gellie, S. Barbieri, J.-F. Lampin, P. Filloux, C. Manquest, C. Sirtori, I. Sagnes, S. P. Khanna, E. H. Linfield, A. G. Davies, H. Beere, and D. Ritchie, “Injection-locking of terahertz quantum cascade lasers up to 35 GHz using RF amplitude modulation,” Opt. Express18, 20799–20816 (2010).
[CrossRef] [PubMed]

H.-W. Hubers, S. Pavlov, H. Richter, A. Semenov, L. Mahler, A. Tredicucci, H. Beere, and D. Ritchie, “High-resolution gas phase spectroscopy with a distributed feedback terahertz quantum cascade laser,” Appl. Phys. Lett.89, 061115 (2006).
[CrossRef]

G. Scalari, L. Ajili, J. Faist, H. Beere, E. Linfield, D. Ritchie, and G. Davies, “Far-infrared (λ= 87 μm) bound-to-continuum quantum-cascade lasers operating up to 90 K,” Appl. Phys. Lett.82, 3165–3167 (2003).
[CrossRef]

Beere, H. E.

R. P. Green, J. H. Xu, L. Mahler, A. Tredicucci, F. Beltram, G. Giuliani, H. E. Beere, and D. A. Ritchie, “Linewidth enhancement factor of terahertz quantum cascade lasers,” Appl. Phys. Lett.92, 071106 (2008).
[CrossRef]

S. Barbieri, J. Alton, H. E. Beere, J. Fowler, E. H. Linfield, and D. A. Ritchie, “2.9 THz quantum cascade lasers operating up to 70 K in continuous wave,” Appl. Phys. Lett.85, 1674 (2004).
[CrossRef]

R. Köhler, A. Tredicucci, F. Beltram, H. E. Beere, E. H. Linfield, A. G. Davies, D. A. Ritchie, R. C. Iotti, and F. Rossi, “Terahertz semiconductor-heterostructure laser,” Nature417, 156–159 (2002).
[CrossRef] [PubMed]

Beltram, F.

R. P. Green, J. H. Xu, L. Mahler, A. Tredicucci, F. Beltram, G. Giuliani, H. E. Beere, and D. A. Ritchie, “Linewidth enhancement factor of terahertz quantum cascade lasers,” Appl. Phys. Lett.92, 071106 (2008).
[CrossRef]

R. Köhler, A. Tredicucci, F. Beltram, H. E. Beere, E. H. Linfield, A. G. Davies, D. A. Ritchie, R. C. Iotti, and F. Rossi, “Terahertz semiconductor-heterostructure laser,” Nature417, 156–159 (2002).
[CrossRef] [PubMed]

Bertling, K.

Y. L. Lim, K. Bertling, P. Rio, J. Tucker, and A. Rakic, “Displacement and distance measurement using the change in junction voltage across a laser diode due to the self-mixing effect,” in Photonics: Design, Technology, and Packaging II, D. Abbott, Y. S. Kivshar, H. H. Rubinsztein-Dunlop, and S. Fan, eds., Proc. SPIE 6038, 60381O-1 (2006).

Bès, C.

G. Plantier, C. Bès, and T. Bosch, “Behavioral model of a self-mixing laser diode sensor,” IEEE J. Quantum Electron.41, 1157–1167 (2005).
[CrossRef]

T. Bosch, C. Bès, L. Scalise, and G. Plantier, Encyclopedia of Sensors (American Scientific Publishers, 2006), chap. Optical feedback interferometry, pp. 1–20.

Bosch, T.

G. Plantier, C. Bès, and T. Bosch, “Behavioral model of a self-mixing laser diode sensor,” IEEE J. Quantum Electron.41, 1157–1167 (2005).
[CrossRef]

G. Giuliani, M. Norgia, S. Donati, and T. Bosch, “Laser diode self-mixing technique for sensing applications,” J. Opt. A: Pure Appl. Opt.4, S283–S294 (2002).
[CrossRef]

T. Bosch, C. Bès, L. Scalise, and G. Plantier, Encyclopedia of Sensors (American Scientific Publishers, 2006), chap. Optical feedback interferometry, pp. 1–20.

Bryant, G.

G. Bryant, Principles of microwave measurements(P. Peregrinus Ltd. on behalf of the Institution of Electrical Engineers, 1993).
[CrossRef]

Burghoff, D.

Burnett, A.

Burnett, A. D.

A. G. Davies, A. D. Burnett, W. Fan, E. H. Linfield, and J. E. Cunningham, “Terahertz spectroscopy of explosives and drugs,” Mater. Today11, 18–26 (2008).
[CrossRef]

Chakraborty, S.

S. P. Khanna, S. Chakraborty, M. Lachab, N. M. Hinchcliffe, E. H. Linfield, and A. G. Davies, “The growth and measurement of terahertz quantum cascade lasers,” Physica E: Low Dimens. Syst. Nanostruct.40, 1859–1861 (2008).
[CrossRef]

P. Dean, M. U. Shaukat, S. P. Khanna, S. Chakraborty, M. Lachab, A. Burnett, G. Davies, and E. H. Linfield, “Absorption-sensitive diffuse reflection imaging of concealed powders using a terahertz quantum cascade laser,” Opt. Express16, 5997–6007 (2008).
[CrossRef] [PubMed]

Chan, W. L.

W. L. Chan, J. Deibel, and D. M. Mittleman, “Imaging with terahertz radiation,” Rep. Prog. Phys.70, 1325 (2007).
[CrossRef]

Chandrayan, N.

Chatterjee, S.

S. Wietzke, C. Jansen, M. Reuter, T. Jung, D. Kraft, S. Chatterjee, B. Fischer, and M. Koch, “Terahertz spectroscopy on polymers: A review of morphological studies,” J. Mol. Struct.1006, 41–51 (2011).
[CrossRef]

Chen, Y.

X. Lu, N. Karpowicz, Y. Chen, and X.-C. Zhang, “Systematic study of broadband terahertz gas sensor,” Appl. Phys. Lett.93, 261106 (2008).
[CrossRef]

Colombelli, R.

S. Barbieri, P. Gellie, G. Santarelli, L. Ding, W. Maineult, C. Sirtori, R. Colombelli, H. Beere, and D. Ritchie, “Phase-locking of a 2.7-THz quantum cascade laser to a mode-locked erbium-doped fibre laser,” Nature Photon.4, 636–640 (2010).
[CrossRef]

Consolino, L.

M. S. Vitiello, L. Consolino, S. Bartalini, A. Taschin, A. Tredicucci, M. Inguscio, and P. De Natale, “Quantum-limited frequency fluctuations in a terahertz laser,” Nat. Photonics6, 525–528 (2012).
[CrossRef]

Cooke, D. G.

P. U. Jepsen, D. G. Cooke, and M. Koch, “Terahertz spectroscopy and imaging — Modern techniques and applications,” Laser Photon. Rev.5, 124–166 (2011).
[CrossRef]

Coulombe, M. J.

Coutaz, J.-L.

L. Duvillaret, F. Garet, and J.-L. Coutaz, “A reliable method for extraction of material parameters in terahertz time-domain spectroscopy,” IEEE J. Sel. Top. Quantum Electron.2, 739–746 (1996).
[CrossRef]

Cunningham, J.

Cunningham, J. E.

A. G. Davies, A. D. Burnett, W. Fan, E. H. Linfield, and J. E. Cunningham, “Terahertz spectroscopy of explosives and drugs,” Mater. Today11, 18–26 (2008).
[CrossRef]

Cunningham, P.

P. Cunningham, N. Valdes, F. Vallejo, L. Hayden, B. Polishak, X. Zhou, J. Luo, A. Jen, J. Williams, and R. Twieg, “Broadband terahertz characterization of the refractive index and absorption of some important polymeric and organic electro-optic materials,” J. Appl. Phys.109, 043505–043505 (2011).
[CrossRef]

X. Zheng, C. V. McLaughlin, P. Cunningham, and L. M. Hayden, “Organic broadband terahertz sources and sensors,” J. Nanoelectron. Optoelectron.2, 58–76 (2007).
[CrossRef]

Danylov, A. A.

Darmo, J.

Davies, A. G.

S. Barbieri, M. Ravaro, P. Gellie, G. Santarelli, C. Manquest, C. Sirtori, S. P. Khanna, E. H. Linfield, and A. G. Davies, “Coherent sampling of active mode-locked terahertz quantum cascade lasers and frequency synthesis,” Nature Photon.5, 306–313 (2011).
[CrossRef]

P. Dean, Y. L. Lim, A. Valavanis, R. Kliese, M. Nikolić, S. P. Khanna, M. Lachab, D. Indjin, Z. Ikonić, P. Harrison, A. D. Rakić, E. H. Linfield, and A. G. Davies, “Terahertz imaging through self-mixing in a quantum cascade laser,” Opt. Lett.36, 2587–2589 (2011).
[CrossRef] [PubMed]

Y. L. Lim, P. Dean, M. Nikolić, R. Kliese, S. P. Khanna, M. Lachab, A. Valavanis, D. Indjin, Z. Ikonić, P. Harrison, E. H. Linfield, A. G. Davies, S. J. Wilson, and A. D. Rakić, “Demonstration of a self-mixing displacement sensor based on terahertz quantum cascade lasers,” Appl. Phys. Lett.99, 081108 (2011).
[CrossRef]

P. Gellie, S. Barbieri, J.-F. Lampin, P. Filloux, C. Manquest, C. Sirtori, I. Sagnes, S. P. Khanna, E. H. Linfield, A. G. Davies, H. Beere, and D. Ritchie, “Injection-locking of terahertz quantum cascade lasers up to 35 GHz using RF amplitude modulation,” Opt. Express18, 20799–20816 (2010).
[CrossRef] [PubMed]

P. Dean, N. K. Saat, S. P. Khanna, M. Salih, A. Burnett, J. Cunningham, E. H. Linfield, and A. G. Davies, “Dual-frequency imaging using an electrically tunable terahertz quantum cascade laser,” Opt. Express17, 20631–20641 (2009).
[CrossRef] [PubMed]

S. P. Khanna, S. Chakraborty, M. Lachab, N. M. Hinchcliffe, E. H. Linfield, and A. G. Davies, “The growth and measurement of terahertz quantum cascade lasers,” Physica E: Low Dimens. Syst. Nanostruct.40, 1859–1861 (2008).
[CrossRef]

A. G. Davies, A. D. Burnett, W. Fan, E. H. Linfield, and J. E. Cunningham, “Terahertz spectroscopy of explosives and drugs,” Mater. Today11, 18–26 (2008).
[CrossRef]

W. H. Fan, A. Burnett, P. C. Upadhya, J. Cunningham, E. H. Linfield, and A. G. Davies, “Far-infrared spectroscopic characterization of explosives for security applications using broadband terahertz time-domain spectroscopy,” Appl. Spectrosc.61, 638–643 (2007).
[CrossRef] [PubMed]

R. Köhler, A. Tredicucci, F. Beltram, H. E. Beere, E. H. Linfield, A. G. Davies, D. A. Ritchie, R. C. Iotti, and F. Rossi, “Terahertz semiconductor-heterostructure laser,” Nature417, 156–159 (2002).
[CrossRef] [PubMed]

Davies, G.

P. Dean, M. U. Shaukat, S. P. Khanna, S. Chakraborty, M. Lachab, A. Burnett, G. Davies, and E. H. Linfield, “Absorption-sensitive diffuse reflection imaging of concealed powders using a terahertz quantum cascade laser,” Opt. Express16, 5997–6007 (2008).
[CrossRef] [PubMed]

G. Scalari, L. Ajili, J. Faist, H. Beere, E. Linfield, D. Ritchie, and G. Davies, “Far-infrared (λ= 87 μm) bound-to-continuum quantum-cascade lasers operating up to 90 K,” Appl. Phys. Lett.82, 3165–3167 (2003).
[CrossRef]

De Natale, P.

M. S. Vitiello, L. Consolino, S. Bartalini, A. Taschin, A. Tredicucci, M. Inguscio, and P. De Natale, “Quantum-limited frequency fluctuations in a terahertz laser,” Nat. Photonics6, 525–528 (2012).
[CrossRef]

Dean, P.

Debbage, P.

Deibel, J.

W. L. Chan, J. Deibel, and D. M. Mittleman, “Imaging with terahertz radiation,” Rep. Prog. Phys.70, 1325 (2007).
[CrossRef]

Ding, L.

S. Barbieri, P. Gellie, G. Santarelli, L. Ding, W. Maineult, C. Sirtori, R. Colombelli, H. Beere, and D. Ritchie, “Phase-locking of a 2.7-THz quantum cascade laser to a mode-locked erbium-doped fibre laser,” Nature Photon.4, 636–640 (2010).
[CrossRef]

Donati, S.

S. Donati, “Developing self-mixing interferometry for instrumentation and measurements,” Laser Photon. Rev.6, 393–417 (2012).
[CrossRef]

S. Donati, “Responsivity and noise of self-mixing photodetection schemes,” IEEE J. Quantum Electron.47, 1428–1433 (2011).
[CrossRef]

G. Giuliani, M. Norgia, S. Donati, and T. Bosch, “Laser diode self-mixing technique for sensing applications,” J. Opt. A: Pure Appl. Opt.4, S283–S294 (2002).
[CrossRef]

G. Giuliani and S. Donati, Unlocking Dynamical Diversity: Optical Feedback Effects on Semiconductor Lasers (John Wiley & Sons, 2005), chap. 7: Laser Interferometry.

Duvillaret, L.

L. Duvillaret, F. Garet, and J.-L. Coutaz, “A reliable method for extraction of material parameters in terahertz time-domain spectroscopy,” IEEE J. Sel. Top. Quantum Electron.2, 739–746 (1996).
[CrossRef]

Faist, J.

J. Darmo, V. Tamosiunas, G. Fasching, J. Kröll, K. Unterrainer, M. Beck, M. Giovannini, J. Faist, C. Kremser, and P. Debbage, “Imaging with a Terahertz quantum cascade laser,” Opt. Express12, 1879–1884 (2004).
[CrossRef] [PubMed]

G. Scalari, L. Ajili, J. Faist, H. Beere, E. Linfield, D. Ritchie, and G. Davies, “Far-infrared (λ= 87 μm) bound-to-continuum quantum-cascade lasers operating up to 90 K,” Appl. Phys. Lett.82, 3165–3167 (2003).
[CrossRef]

Fan, W.

A. G. Davies, A. D. Burnett, W. Fan, E. H. Linfield, and J. E. Cunningham, “Terahertz spectroscopy of explosives and drugs,” Mater. Today11, 18–26 (2008).
[CrossRef]

Fan, W. H.

Fasching, G.

Filloux, P.

Fischer, B.

S. Wietzke, C. Jansen, M. Reuter, T. Jung, D. Kraft, S. Chatterjee, B. Fischer, and M. Koch, “Terahertz spectroscopy on polymers: A review of morphological studies,” J. Mol. Struct.1006, 41–51 (2011).
[CrossRef]

Fowler, J.

S. Barbieri, J. Alton, H. E. Beere, J. Fowler, E. H. Linfield, and D. A. Ritchie, “2.9 THz quantum cascade lasers operating up to 70 K in continuous wave,” Appl. Phys. Lett.85, 1674 (2004).
[CrossRef]

Garet, F.

L. Duvillaret, F. Garet, and J.-L. Coutaz, “A reliable method for extraction of material parameters in terahertz time-domain spectroscopy,” IEEE J. Sel. Top. Quantum Electron.2, 739–746 (1996).
[CrossRef]

Gatesman, A. J.

Gellie, P.

S. Barbieri, M. Ravaro, P. Gellie, G. Santarelli, C. Manquest, C. Sirtori, S. P. Khanna, E. H. Linfield, and A. G. Davies, “Coherent sampling of active mode-locked terahertz quantum cascade lasers and frequency synthesis,” Nature Photon.5, 306–313 (2011).
[CrossRef]

S. Barbieri, P. Gellie, G. Santarelli, L. Ding, W. Maineult, C. Sirtori, R. Colombelli, H. Beere, and D. Ritchie, “Phase-locking of a 2.7-THz quantum cascade laser to a mode-locked erbium-doped fibre laser,” Nature Photon.4, 636–640 (2010).
[CrossRef]

P. Gellie, S. Barbieri, J.-F. Lampin, P. Filloux, C. Manquest, C. Sirtori, I. Sagnes, S. P. Khanna, E. H. Linfield, A. G. Davies, H. Beere, and D. Ritchie, “Injection-locking of terahertz quantum cascade lasers up to 35 GHz using RF amplitude modulation,” Opt. Express18, 20799–20816 (2010).
[CrossRef] [PubMed]

Giles, R. H.

Giovannini, M.

Giuliani, G.

R. P. Green, J. H. Xu, L. Mahler, A. Tredicucci, F. Beltram, G. Giuliani, H. E. Beere, and D. A. Ritchie, “Linewidth enhancement factor of terahertz quantum cascade lasers,” Appl. Phys. Lett.92, 071106 (2008).
[CrossRef]

G. Giuliani, M. Norgia, S. Donati, and T. Bosch, “Laser diode self-mixing technique for sensing applications,” J. Opt. A: Pure Appl. Opt.4, S283–S294 (2002).
[CrossRef]

G. Giuliani and S. Donati, Unlocking Dynamical Diversity: Optical Feedback Effects on Semiconductor Lasers (John Wiley & Sons, 2005), chap. 7: Laser Interferometry.

Goodhue, W. D.

Goyette, T. M.

Green, R. P.

R. P. Green, J. H. Xu, L. Mahler, A. Tredicucci, F. Beltram, G. Giuliani, H. E. Beere, and D. A. Ritchie, “Linewidth enhancement factor of terahertz quantum cascade lasers,” Appl. Phys. Lett.92, 071106 (2008).
[CrossRef]

Grischkowsky, D.

Han, P.

P. Han, M. Tani, M. Usami, S. Kono, R. Kersting, and X.-C. Zhang, “A direct comparison between terahertz time-domain spectroscopy and far-infrared fourier transform spectroscopy,” J. Appl. Phys.89, 2357–2359 (2001).
[CrossRef]

Harrison, P.

P. Dean, Y. L. Lim, A. Valavanis, R. Kliese, M. Nikolić, S. P. Khanna, M. Lachab, D. Indjin, Z. Ikonić, P. Harrison, A. D. Rakić, E. H. Linfield, and A. G. Davies, “Terahertz imaging through self-mixing in a quantum cascade laser,” Opt. Lett.36, 2587–2589 (2011).
[CrossRef] [PubMed]

Y. L. Lim, P. Dean, M. Nikolić, R. Kliese, S. P. Khanna, M. Lachab, A. Valavanis, D. Indjin, Z. Ikonić, P. Harrison, E. H. Linfield, A. G. Davies, S. J. Wilson, and A. D. Rakić, “Demonstration of a self-mixing displacement sensor based on terahertz quantum cascade lasers,” Appl. Phys. Lett.99, 081108 (2011).
[CrossRef]

D. Indjin, P. Harrison, R. Kelsall, and Z. Ikonić, “Mechanisms of temperature performance degradation in terahertz quantum-cascade lasers,” Appl. Phys. Lett.82, 1347–1349 (2003).
[CrossRef]

Harsha, S. S.

Hayden, L.

P. Cunningham, N. Valdes, F. Vallejo, L. Hayden, B. Polishak, X. Zhou, J. Luo, A. Jen, J. Williams, and R. Twieg, “Broadband terahertz characterization of the refractive index and absorption of some important polymeric and organic electro-optic materials,” J. Appl. Phys.109, 043505–043505 (2011).
[CrossRef]

Hayden, L. M.

C. V. McLaughlin, L. M. Hayden, B. Polishak, S. Huang, J. Luo, T.-D. Kim, and A. K.-Y. Jen, “Wideband 15 THz response using organic electro-optic polymer emitter-sensor pairs at telecommunication wavelengths,” Appl. Phys. Lett.92, 151107 (2008).
[CrossRef]

X. Zheng, C. V. McLaughlin, P. Cunningham, and L. M. Hayden, “Organic broadband terahertz sources and sensors,” J. Nanoelectron. Optoelectron.2, 58–76 (2007).
[CrossRef]

Hinchcliffe, N. M.

S. P. Khanna, S. Chakraborty, M. Lachab, N. M. Hinchcliffe, E. H. Linfield, and A. G. Davies, “The growth and measurement of terahertz quantum cascade lasers,” Physica E: Low Dimens. Syst. Nanostruct.40, 1859–1861 (2008).
[CrossRef]

Hu, B.

Hu, Q.

A. W. M. Lee, T.-Y. Kao, D. Burghoff, Q. Hu, and J. L. Reno, “Terahertz tomography using quantum-cascade lasers,” Opt. Lett.37, 217–219 (2012).
[CrossRef] [PubMed]

A. W. Lee, Q. Qin, S. Kumar, B. S. Williams, Q. Hu, and J. L. Reno, “Real-time terahertz imaging over a standoff distance (≫25 meters),” Appl. Phys. Lett.89, 141125–141125 (2006).
[CrossRef]

Huang, S.

C. V. McLaughlin, L. M. Hayden, B. Polishak, S. Huang, J. Luo, T.-D. Kim, and A. K.-Y. Jen, “Wideband 15 THz response using organic electro-optic polymer emitter-sensor pairs at telecommunication wavelengths,” Appl. Phys. Lett.92, 151107 (2008).
[CrossRef]

Hubers, H.-W.

H.-W. Hubers, S. Pavlov, H. Richter, A. Semenov, L. Mahler, A. Tredicucci, H. Beere, and D. Ritchie, “High-resolution gas phase spectroscopy with a distributed feedback terahertz quantum cascade laser,” Appl. Phys. Lett.89, 061115 (2006).
[CrossRef]

Ikonic, Z.

P. Dean, Y. L. Lim, A. Valavanis, R. Kliese, M. Nikolić, S. P. Khanna, M. Lachab, D. Indjin, Z. Ikonić, P. Harrison, A. D. Rakić, E. H. Linfield, and A. G. Davies, “Terahertz imaging through self-mixing in a quantum cascade laser,” Opt. Lett.36, 2587–2589 (2011).
[CrossRef] [PubMed]

Y. L. Lim, P. Dean, M. Nikolić, R. Kliese, S. P. Khanna, M. Lachab, A. Valavanis, D. Indjin, Z. Ikonić, P. Harrison, E. H. Linfield, A. G. Davies, S. J. Wilson, and A. D. Rakić, “Demonstration of a self-mixing displacement sensor based on terahertz quantum cascade lasers,” Appl. Phys. Lett.99, 081108 (2011).
[CrossRef]

D. Indjin, P. Harrison, R. Kelsall, and Z. Ikonić, “Mechanisms of temperature performance degradation in terahertz quantum-cascade lasers,” Appl. Phys. Lett.82, 1347–1349 (2003).
[CrossRef]

Indjin, D.

Y. L. Lim, P. Dean, M. Nikolić, R. Kliese, S. P. Khanna, M. Lachab, A. Valavanis, D. Indjin, Z. Ikonić, P. Harrison, E. H. Linfield, A. G. Davies, S. J. Wilson, and A. D. Rakić, “Demonstration of a self-mixing displacement sensor based on terahertz quantum cascade lasers,” Appl. Phys. Lett.99, 081108 (2011).
[CrossRef]

P. Dean, Y. L. Lim, A. Valavanis, R. Kliese, M. Nikolić, S. P. Khanna, M. Lachab, D. Indjin, Z. Ikonić, P. Harrison, A. D. Rakić, E. H. Linfield, and A. G. Davies, “Terahertz imaging through self-mixing in a quantum cascade laser,” Opt. Lett.36, 2587–2589 (2011).
[CrossRef] [PubMed]

D. Indjin, P. Harrison, R. Kelsall, and Z. Ikonić, “Mechanisms of temperature performance degradation in terahertz quantum-cascade lasers,” Appl. Phys. Lett.82, 1347–1349 (2003).
[CrossRef]

Inguscio, M.

M. S. Vitiello, L. Consolino, S. Bartalini, A. Taschin, A. Tredicucci, M. Inguscio, and P. De Natale, “Quantum-limited frequency fluctuations in a terahertz laser,” Nat. Photonics6, 525–528 (2012).
[CrossRef]

Iotti, R. C.

R. Köhler, A. Tredicucci, F. Beltram, H. E. Beere, E. H. Linfield, A. G. Davies, D. A. Ritchie, R. C. Iotti, and F. Rossi, “Terahertz semiconductor-heterostructure laser,” Nature417, 156–159 (2002).
[CrossRef] [PubMed]

Itoh, T.

H. Shimosato, M. Ashida, T. Itoh, S. Saito, and K. Sakai, “Ultrabroadband detection of terahertz radiation from 0.1 to 100 THz with photoconductive antenna,” in “Ultrafast Optics V,” (Springer, 2007), pp. 317–323.
[CrossRef]

Jagtap, V.

M. Ravaro, V. Jagtap, G. Santarelli, C. Sirtori, L. Li, S. Khanna, E. Linfield, and S. Barbieri, “Continuous-wave coherent imaging with terahertz quantum cascade lasers using electro-optic harmonic sampling,” Appl. Phys. Lett.102, 091107 (2013).
[CrossRef]

M. Ravaro, S. Barbieri, G. Santarelli, V. Jagtap, C. Manquest, C. Sirtori, S. Khanna, and E. Linfield, “Measurement of the intrinsic linewidth of terahertz quantum cascade lasers using a near-infrared frequency comb,” Opt. Express20, 25654–25661 (2012).
[CrossRef] [PubMed]

Jansen, C.

S. Wietzke, C. Jansen, M. Reuter, T. Jung, D. Kraft, S. Chatterjee, B. Fischer, and M. Koch, “Terahertz spectroscopy on polymers: A review of morphological studies,” J. Mol. Struct.1006, 41–51 (2011).
[CrossRef]

Jen, A.

P. Cunningham, N. Valdes, F. Vallejo, L. Hayden, B. Polishak, X. Zhou, J. Luo, A. Jen, J. Williams, and R. Twieg, “Broadband terahertz characterization of the refractive index and absorption of some important polymeric and organic electro-optic materials,” J. Appl. Phys.109, 043505–043505 (2011).
[CrossRef]

Jen, A. K.-Y.

C. V. McLaughlin, L. M. Hayden, B. Polishak, S. Huang, J. Luo, T.-D. Kim, and A. K.-Y. Jen, “Wideband 15 THz response using organic electro-optic polymer emitter-sensor pairs at telecommunication wavelengths,” Appl. Phys. Lett.92, 151107 (2008).
[CrossRef]

Jeon, S.-G.

Y.-S. Jin, G.-J. Kim, and S.-G. Jeon, “Terahertz dielectric properties of polymers,” J. Korean Phys. Soc.49, 513–517 (2006).

Jepsen, P. U.

P. U. Jepsen, D. G. Cooke, and M. Koch, “Terahertz spectroscopy and imaging — Modern techniques and applications,” Laser Photon. Rev.5, 124–166 (2011).
[CrossRef]

Jin, Y.-S.

Y.-S. Jin, G.-J. Kim, and S.-G. Jeon, “Terahertz dielectric properties of polymers,” J. Korean Phys. Soc.49, 513–517 (2006).

Jung, T.

S. Wietzke, C. Jansen, M. Reuter, T. Jung, D. Kraft, S. Chatterjee, B. Fischer, and M. Koch, “Terahertz spectroscopy on polymers: A review of morphological studies,” J. Mol. Struct.1006, 41–51 (2011).
[CrossRef]

Kao, T.-Y.

Karpowicz, N.

X. Lu, N. Karpowicz, Y. Chen, and X.-C. Zhang, “Systematic study of broadband terahertz gas sensor,” Appl. Phys. Lett.93, 261106 (2008).
[CrossRef]

Kelsall, R.

D. Indjin, P. Harrison, R. Kelsall, and Z. Ikonić, “Mechanisms of temperature performance degradation in terahertz quantum-cascade lasers,” Appl. Phys. Lett.82, 1347–1349 (2003).
[CrossRef]

Kersting, R.

P. Han, M. Tani, M. Usami, S. Kono, R. Kersting, and X.-C. Zhang, “A direct comparison between terahertz time-domain spectroscopy and far-infrared fourier transform spectroscopy,” J. Appl. Phys.89, 2357–2359 (2001).
[CrossRef]

Khanna, S.

M. Ravaro, V. Jagtap, G. Santarelli, C. Sirtori, L. Li, S. Khanna, E. Linfield, and S. Barbieri, “Continuous-wave coherent imaging with terahertz quantum cascade lasers using electro-optic harmonic sampling,” Appl. Phys. Lett.102, 091107 (2013).
[CrossRef]

M. Ravaro, S. Barbieri, G. Santarelli, V. Jagtap, C. Manquest, C. Sirtori, S. Khanna, and E. Linfield, “Measurement of the intrinsic linewidth of terahertz quantum cascade lasers using a near-infrared frequency comb,” Opt. Express20, 25654–25661 (2012).
[CrossRef] [PubMed]

Khanna, S. P.

S. Barbieri, M. Ravaro, P. Gellie, G. Santarelli, C. Manquest, C. Sirtori, S. P. Khanna, E. H. Linfield, and A. G. Davies, “Coherent sampling of active mode-locked terahertz quantum cascade lasers and frequency synthesis,” Nature Photon.5, 306–313 (2011).
[CrossRef]

P. Dean, Y. L. Lim, A. Valavanis, R. Kliese, M. Nikolić, S. P. Khanna, M. Lachab, D. Indjin, Z. Ikonić, P. Harrison, A. D. Rakić, E. H. Linfield, and A. G. Davies, “Terahertz imaging through self-mixing in a quantum cascade laser,” Opt. Lett.36, 2587–2589 (2011).
[CrossRef] [PubMed]

Y. L. Lim, P. Dean, M. Nikolić, R. Kliese, S. P. Khanna, M. Lachab, A. Valavanis, D. Indjin, Z. Ikonić, P. Harrison, E. H. Linfield, A. G. Davies, S. J. Wilson, and A. D. Rakić, “Demonstration of a self-mixing displacement sensor based on terahertz quantum cascade lasers,” Appl. Phys. Lett.99, 081108 (2011).
[CrossRef]

P. Gellie, S. Barbieri, J.-F. Lampin, P. Filloux, C. Manquest, C. Sirtori, I. Sagnes, S. P. Khanna, E. H. Linfield, A. G. Davies, H. Beere, and D. Ritchie, “Injection-locking of terahertz quantum cascade lasers up to 35 GHz using RF amplitude modulation,” Opt. Express18, 20799–20816 (2010).
[CrossRef] [PubMed]

P. Dean, N. K. Saat, S. P. Khanna, M. Salih, A. Burnett, J. Cunningham, E. H. Linfield, and A. G. Davies, “Dual-frequency imaging using an electrically tunable terahertz quantum cascade laser,” Opt. Express17, 20631–20641 (2009).
[CrossRef] [PubMed]

S. P. Khanna, S. Chakraborty, M. Lachab, N. M. Hinchcliffe, E. H. Linfield, and A. G. Davies, “The growth and measurement of terahertz quantum cascade lasers,” Physica E: Low Dimens. Syst. Nanostruct.40, 1859–1861 (2008).
[CrossRef]

P. Dean, M. U. Shaukat, S. P. Khanna, S. Chakraborty, M. Lachab, A. Burnett, G. Davies, and E. H. Linfield, “Absorption-sensitive diffuse reflection imaging of concealed powders using a terahertz quantum cascade laser,” Opt. Express16, 5997–6007 (2008).
[CrossRef] [PubMed]

Kim, G.-J.

Y.-S. Jin, G.-J. Kim, and S.-G. Jeon, “Terahertz dielectric properties of polymers,” J. Korean Phys. Soc.49, 513–517 (2006).

Kim, T.-D.

C. V. McLaughlin, L. M. Hayden, B. Polishak, S. Huang, J. Luo, T.-D. Kim, and A. K.-Y. Jen, “Wideband 15 THz response using organic electro-optic polymer emitter-sensor pairs at telecommunication wavelengths,” Appl. Phys. Lett.92, 151107 (2008).
[CrossRef]

Kliese, R.

Y. L. Lim, P. Dean, M. Nikolić, R. Kliese, S. P. Khanna, M. Lachab, A. Valavanis, D. Indjin, Z. Ikonić, P. Harrison, E. H. Linfield, A. G. Davies, S. J. Wilson, and A. D. Rakić, “Demonstration of a self-mixing displacement sensor based on terahertz quantum cascade lasers,” Appl. Phys. Lett.99, 081108 (2011).
[CrossRef]

P. Dean, Y. L. Lim, A. Valavanis, R. Kliese, M. Nikolić, S. P. Khanna, M. Lachab, D. Indjin, Z. Ikonić, P. Harrison, A. D. Rakić, E. H. Linfield, and A. G. Davies, “Terahertz imaging through self-mixing in a quantum cascade laser,” Opt. Lett.36, 2587–2589 (2011).
[CrossRef] [PubMed]

Kobayashi, K.

R. Lang and K. Kobayashi, “External optical feedback effects on semiconductor injection laser properties,” IEEE J. Quantum Electron.16, 347–355 (1980).
[CrossRef]

Koch, M.

P. U. Jepsen, D. G. Cooke, and M. Koch, “Terahertz spectroscopy and imaging — Modern techniques and applications,” Laser Photon. Rev.5, 124–166 (2011).
[CrossRef]

S. Wietzke, C. Jansen, M. Reuter, T. Jung, D. Kraft, S. Chatterjee, B. Fischer, and M. Koch, “Terahertz spectroscopy on polymers: A review of morphological studies,” J. Mol. Struct.1006, 41–51 (2011).
[CrossRef]

Köhler, R.

R. Köhler, A. Tredicucci, F. Beltram, H. E. Beere, E. H. Linfield, A. G. Davies, D. A. Ritchie, R. C. Iotti, and F. Rossi, “Terahertz semiconductor-heterostructure laser,” Nature417, 156–159 (2002).
[CrossRef] [PubMed]

Kono, S.

P. Han, M. Tani, M. Usami, S. Kono, R. Kersting, and X.-C. Zhang, “A direct comparison between terahertz time-domain spectroscopy and far-infrared fourier transform spectroscopy,” J. Appl. Phys.89, 2357–2359 (2001).
[CrossRef]

Kraft, D.

S. Wietzke, C. Jansen, M. Reuter, T. Jung, D. Kraft, S. Chatterjee, B. Fischer, and M. Koch, “Terahertz spectroscopy on polymers: A review of morphological studies,” J. Mol. Struct.1006, 41–51 (2011).
[CrossRef]

Kremser, C.

Kröll, J.

Kumar, S.

A. W. Lee, Q. Qin, S. Kumar, B. S. Williams, Q. Hu, and J. L. Reno, “Real-time terahertz imaging over a standoff distance (≫25 meters),” Appl. Phys. Lett.89, 141125–141125 (2006).
[CrossRef]

Lachab, M.

P. Dean, Y. L. Lim, A. Valavanis, R. Kliese, M. Nikolić, S. P. Khanna, M. Lachab, D. Indjin, Z. Ikonić, P. Harrison, A. D. Rakić, E. H. Linfield, and A. G. Davies, “Terahertz imaging through self-mixing in a quantum cascade laser,” Opt. Lett.36, 2587–2589 (2011).
[CrossRef] [PubMed]

Y. L. Lim, P. Dean, M. Nikolić, R. Kliese, S. P. Khanna, M. Lachab, A. Valavanis, D. Indjin, Z. Ikonić, P. Harrison, E. H. Linfield, A. G. Davies, S. J. Wilson, and A. D. Rakić, “Demonstration of a self-mixing displacement sensor based on terahertz quantum cascade lasers,” Appl. Phys. Lett.99, 081108 (2011).
[CrossRef]

S. P. Khanna, S. Chakraborty, M. Lachab, N. M. Hinchcliffe, E. H. Linfield, and A. G. Davies, “The growth and measurement of terahertz quantum cascade lasers,” Physica E: Low Dimens. Syst. Nanostruct.40, 1859–1861 (2008).
[CrossRef]

P. Dean, M. U. Shaukat, S. P. Khanna, S. Chakraborty, M. Lachab, A. Burnett, G. Davies, and E. H. Linfield, “Absorption-sensitive diffuse reflection imaging of concealed powders using a terahertz quantum cascade laser,” Opt. Express16, 5997–6007 (2008).
[CrossRef] [PubMed]

Laman, N.

Lampin, J.-F.

Lang, R.

R. Lang and K. Kobayashi, “External optical feedback effects on semiconductor injection laser properties,” IEEE J. Quantum Electron.16, 347–355 (1980).
[CrossRef]

Lee, A. W.

A. W. Lee, Q. Qin, S. Kumar, B. S. Williams, Q. Hu, and J. L. Reno, “Real-time terahertz imaging over a standoff distance (≫25 meters),” Appl. Phys. Lett.89, 141125–141125 (2006).
[CrossRef]

Lee, A. W. M.

Li, L.

M. Ravaro, V. Jagtap, G. Santarelli, C. Sirtori, L. Li, S. Khanna, E. Linfield, and S. Barbieri, “Continuous-wave coherent imaging with terahertz quantum cascade lasers using electro-optic harmonic sampling,” Appl. Phys. Lett.102, 091107 (2013).
[CrossRef]

Lim, Y. L.

P. Dean, Y. L. Lim, A. Valavanis, R. Kliese, M. Nikolić, S. P. Khanna, M. Lachab, D. Indjin, Z. Ikonić, P. Harrison, A. D. Rakić, E. H. Linfield, and A. G. Davies, “Terahertz imaging through self-mixing in a quantum cascade laser,” Opt. Lett.36, 2587–2589 (2011).
[CrossRef] [PubMed]

Y. L. Lim, P. Dean, M. Nikolić, R. Kliese, S. P. Khanna, M. Lachab, A. Valavanis, D. Indjin, Z. Ikonić, P. Harrison, E. H. Linfield, A. G. Davies, S. J. Wilson, and A. D. Rakić, “Demonstration of a self-mixing displacement sensor based on terahertz quantum cascade lasers,” Appl. Phys. Lett.99, 081108 (2011).
[CrossRef]

Y. L. Lim, K. Bertling, P. Rio, J. Tucker, and A. Rakic, “Displacement and distance measurement using the change in junction voltage across a laser diode due to the self-mixing effect,” in Photonics: Design, Technology, and Packaging II, D. Abbott, Y. S. Kivshar, H. H. Rubinsztein-Dunlop, and S. Fan, eds., Proc. SPIE 6038, 60381O-1 (2006).

Linfield, E.

M. Ravaro, V. Jagtap, G. Santarelli, C. Sirtori, L. Li, S. Khanna, E. Linfield, and S. Barbieri, “Continuous-wave coherent imaging with terahertz quantum cascade lasers using electro-optic harmonic sampling,” Appl. Phys. Lett.102, 091107 (2013).
[CrossRef]

M. Ravaro, S. Barbieri, G. Santarelli, V. Jagtap, C. Manquest, C. Sirtori, S. Khanna, and E. Linfield, “Measurement of the intrinsic linewidth of terahertz quantum cascade lasers using a near-infrared frequency comb,” Opt. Express20, 25654–25661 (2012).
[CrossRef] [PubMed]

G. Scalari, L. Ajili, J. Faist, H. Beere, E. Linfield, D. Ritchie, and G. Davies, “Far-infrared (λ= 87 μm) bound-to-continuum quantum-cascade lasers operating up to 90 K,” Appl. Phys. Lett.82, 3165–3167 (2003).
[CrossRef]

Linfield, E. H.

S. Barbieri, M. Ravaro, P. Gellie, G. Santarelli, C. Manquest, C. Sirtori, S. P. Khanna, E. H. Linfield, and A. G. Davies, “Coherent sampling of active mode-locked terahertz quantum cascade lasers and frequency synthesis,” Nature Photon.5, 306–313 (2011).
[CrossRef]

Y. L. Lim, P. Dean, M. Nikolić, R. Kliese, S. P. Khanna, M. Lachab, A. Valavanis, D. Indjin, Z. Ikonić, P. Harrison, E. H. Linfield, A. G. Davies, S. J. Wilson, and A. D. Rakić, “Demonstration of a self-mixing displacement sensor based on terahertz quantum cascade lasers,” Appl. Phys. Lett.99, 081108 (2011).
[CrossRef]

P. Dean, Y. L. Lim, A. Valavanis, R. Kliese, M. Nikolić, S. P. Khanna, M. Lachab, D. Indjin, Z. Ikonić, P. Harrison, A. D. Rakić, E. H. Linfield, and A. G. Davies, “Terahertz imaging through self-mixing in a quantum cascade laser,” Opt. Lett.36, 2587–2589 (2011).
[CrossRef] [PubMed]

P. Gellie, S. Barbieri, J.-F. Lampin, P. Filloux, C. Manquest, C. Sirtori, I. Sagnes, S. P. Khanna, E. H. Linfield, A. G. Davies, H. Beere, and D. Ritchie, “Injection-locking of terahertz quantum cascade lasers up to 35 GHz using RF amplitude modulation,” Opt. Express18, 20799–20816 (2010).
[CrossRef] [PubMed]

P. Dean, N. K. Saat, S. P. Khanna, M. Salih, A. Burnett, J. Cunningham, E. H. Linfield, and A. G. Davies, “Dual-frequency imaging using an electrically tunable terahertz quantum cascade laser,” Opt. Express17, 20631–20641 (2009).
[CrossRef] [PubMed]

S. P. Khanna, S. Chakraborty, M. Lachab, N. M. Hinchcliffe, E. H. Linfield, and A. G. Davies, “The growth and measurement of terahertz quantum cascade lasers,” Physica E: Low Dimens. Syst. Nanostruct.40, 1859–1861 (2008).
[CrossRef]

A. G. Davies, A. D. Burnett, W. Fan, E. H. Linfield, and J. E. Cunningham, “Terahertz spectroscopy of explosives and drugs,” Mater. Today11, 18–26 (2008).
[CrossRef]

P. Dean, M. U. Shaukat, S. P. Khanna, S. Chakraborty, M. Lachab, A. Burnett, G. Davies, and E. H. Linfield, “Absorption-sensitive diffuse reflection imaging of concealed powders using a terahertz quantum cascade laser,” Opt. Express16, 5997–6007 (2008).
[CrossRef] [PubMed]

W. H. Fan, A. Burnett, P. C. Upadhya, J. Cunningham, E. H. Linfield, and A. G. Davies, “Far-infrared spectroscopic characterization of explosives for security applications using broadband terahertz time-domain spectroscopy,” Appl. Spectrosc.61, 638–643 (2007).
[CrossRef] [PubMed]

S. Barbieri, J. Alton, H. E. Beere, J. Fowler, E. H. Linfield, and D. A. Ritchie, “2.9 THz quantum cascade lasers operating up to 70 K in continuous wave,” Appl. Phys. Lett.85, 1674 (2004).
[CrossRef]

R. Köhler, A. Tredicucci, F. Beltram, H. E. Beere, E. H. Linfield, A. G. Davies, D. A. Ritchie, R. C. Iotti, and F. Rossi, “Terahertz semiconductor-heterostructure laser,” Nature417, 156–159 (2002).
[CrossRef] [PubMed]

Lu, X.

X. Lu, N. Karpowicz, Y. Chen, and X.-C. Zhang, “Systematic study of broadband terahertz gas sensor,” Appl. Phys. Lett.93, 261106 (2008).
[CrossRef]

Luo, J.

P. Cunningham, N. Valdes, F. Vallejo, L. Hayden, B. Polishak, X. Zhou, J. Luo, A. Jen, J. Williams, and R. Twieg, “Broadband terahertz characterization of the refractive index and absorption of some important polymeric and organic electro-optic materials,” J. Appl. Phys.109, 043505–043505 (2011).
[CrossRef]

C. V. McLaughlin, L. M. Hayden, B. Polishak, S. Huang, J. Luo, T.-D. Kim, and A. K.-Y. Jen, “Wideband 15 THz response using organic electro-optic polymer emitter-sensor pairs at telecommunication wavelengths,” Appl. Phys. Lett.92, 151107 (2008).
[CrossRef]

Mahler, L.

R. P. Green, J. H. Xu, L. Mahler, A. Tredicucci, F. Beltram, G. Giuliani, H. E. Beere, and D. A. Ritchie, “Linewidth enhancement factor of terahertz quantum cascade lasers,” Appl. Phys. Lett.92, 071106 (2008).
[CrossRef]

H.-W. Hubers, S. Pavlov, H. Richter, A. Semenov, L. Mahler, A. Tredicucci, H. Beere, and D. Ritchie, “High-resolution gas phase spectroscopy with a distributed feedback terahertz quantum cascade laser,” Appl. Phys. Lett.89, 061115 (2006).
[CrossRef]

Maineult, W.

S. Barbieri, P. Gellie, G. Santarelli, L. Ding, W. Maineult, C. Sirtori, R. Colombelli, H. Beere, and D. Ritchie, “Phase-locking of a 2.7-THz quantum cascade laser to a mode-locked erbium-doped fibre laser,” Nature Photon.4, 636–640 (2010).
[CrossRef]

Manquest, C.

McLaughlin, C. V.

C. V. McLaughlin, L. M. Hayden, B. Polishak, S. Huang, J. Luo, T.-D. Kim, and A. K.-Y. Jen, “Wideband 15 THz response using organic electro-optic polymer emitter-sensor pairs at telecommunication wavelengths,” Appl. Phys. Lett.92, 151107 (2008).
[CrossRef]

X. Zheng, C. V. McLaughlin, P. Cunningham, and L. M. Hayden, “Organic broadband terahertz sources and sensors,” J. Nanoelectron. Optoelectron.2, 58–76 (2007).
[CrossRef]

Melinger, J. S.

Mittleman, D. M.

W. L. Chan, J. Deibel, and D. M. Mittleman, “Imaging with terahertz radiation,” Rep. Prog. Phys.70, 1325 (2007).
[CrossRef]

Naftaly, M.

M. Naftaly, “Metrology issues and solutions in THz time-domain spectroscopy: Noise, errors, calibration,” IEEE Sens. J.13, 8–17 (2013).
[CrossRef]

Nikolic, M.

Y. L. Lim, P. Dean, M. Nikolić, R. Kliese, S. P. Khanna, M. Lachab, A. Valavanis, D. Indjin, Z. Ikonić, P. Harrison, E. H. Linfield, A. G. Davies, S. J. Wilson, and A. D. Rakić, “Demonstration of a self-mixing displacement sensor based on terahertz quantum cascade lasers,” Appl. Phys. Lett.99, 081108 (2011).
[CrossRef]

P. Dean, Y. L. Lim, A. Valavanis, R. Kliese, M. Nikolić, S. P. Khanna, M. Lachab, D. Indjin, Z. Ikonić, P. Harrison, A. D. Rakić, E. H. Linfield, and A. G. Davies, “Terahertz imaging through self-mixing in a quantum cascade laser,” Opt. Lett.36, 2587–2589 (2011).
[CrossRef] [PubMed]

Nixon, W. E.

Norgia, M.

G. Giuliani, M. Norgia, S. Donati, and T. Bosch, “Laser diode self-mixing technique for sensing applications,” J. Opt. A: Pure Appl. Opt.4, S283–S294 (2002).
[CrossRef]

Nuss, M.

Pavlov, S.

H.-W. Hubers, S. Pavlov, H. Richter, A. Semenov, L. Mahler, A. Tredicucci, H. Beere, and D. Ritchie, “High-resolution gas phase spectroscopy with a distributed feedback terahertz quantum cascade laser,” Appl. Phys. Lett.89, 061115 (2006).
[CrossRef]

Petermann, K.

K. Petermann, Laser diode modulation and noise, 3rd ed. (Springer, 1991).

Pierce, I.

P. Spencer, P. Rees, and I. Pierce, Unlocking Dynamical Diversity: Optical Feedback Effects on Semiconductor Lasers (John Wiley & Sons, 2005), chap. 2: Theoretical Analysis.

Plantier, G.

G. Plantier, C. Bès, and T. Bosch, “Behavioral model of a self-mixing laser diode sensor,” IEEE J. Quantum Electron.41, 1157–1167 (2005).
[CrossRef]

T. Bosch, C. Bès, L. Scalise, and G. Plantier, Encyclopedia of Sensors (American Scientific Publishers, 2006), chap. Optical feedback interferometry, pp. 1–20.

Polishak, B.

P. Cunningham, N. Valdes, F. Vallejo, L. Hayden, B. Polishak, X. Zhou, J. Luo, A. Jen, J. Williams, and R. Twieg, “Broadband terahertz characterization of the refractive index and absorption of some important polymeric and organic electro-optic materials,” J. Appl. Phys.109, 043505–043505 (2011).
[CrossRef]

C. V. McLaughlin, L. M. Hayden, B. Polishak, S. Huang, J. Luo, T.-D. Kim, and A. K.-Y. Jen, “Wideband 15 THz response using organic electro-optic polymer emitter-sensor pairs at telecommunication wavelengths,” Appl. Phys. Lett.92, 151107 (2008).
[CrossRef]

Qian, X.

Qin, Q.

A. W. Lee, Q. Qin, S. Kumar, B. S. Williams, Q. Hu, and J. L. Reno, “Real-time terahertz imaging over a standoff distance (≫25 meters),” Appl. Phys. Lett.89, 141125–141125 (2006).
[CrossRef]

Rakic, A.

Y. L. Lim, K. Bertling, P. Rio, J. Tucker, and A. Rakic, “Displacement and distance measurement using the change in junction voltage across a laser diode due to the self-mixing effect,” in Photonics: Design, Technology, and Packaging II, D. Abbott, Y. S. Kivshar, H. H. Rubinsztein-Dunlop, and S. Fan, eds., Proc. SPIE 6038, 60381O-1 (2006).

Rakic, A. D.

P. Dean, Y. L. Lim, A. Valavanis, R. Kliese, M. Nikolić, S. P. Khanna, M. Lachab, D. Indjin, Z. Ikonić, P. Harrison, A. D. Rakić, E. H. Linfield, and A. G. Davies, “Terahertz imaging through self-mixing in a quantum cascade laser,” Opt. Lett.36, 2587–2589 (2011).
[CrossRef] [PubMed]

Y. L. Lim, P. Dean, M. Nikolić, R. Kliese, S. P. Khanna, M. Lachab, A. Valavanis, D. Indjin, Z. Ikonić, P. Harrison, E. H. Linfield, A. G. Davies, S. J. Wilson, and A. D. Rakić, “Demonstration of a self-mixing displacement sensor based on terahertz quantum cascade lasers,” Appl. Phys. Lett.99, 081108 (2011).
[CrossRef]

A. D. Rakić, “Algorithm for the determination of intrinsic optical constants of metal films: application to aluminum,” Appl. Opt.34, 4755–4767 (1995).
[CrossRef]

Ravaro, M.

M. Ravaro, V. Jagtap, G. Santarelli, C. Sirtori, L. Li, S. Khanna, E. Linfield, and S. Barbieri, “Continuous-wave coherent imaging with terahertz quantum cascade lasers using electro-optic harmonic sampling,” Appl. Phys. Lett.102, 091107 (2013).
[CrossRef]

M. Ravaro, S. Barbieri, G. Santarelli, V. Jagtap, C. Manquest, C. Sirtori, S. Khanna, and E. Linfield, “Measurement of the intrinsic linewidth of terahertz quantum cascade lasers using a near-infrared frequency comb,” Opt. Express20, 25654–25661 (2012).
[CrossRef] [PubMed]

S. Barbieri, M. Ravaro, P. Gellie, G. Santarelli, C. Manquest, C. Sirtori, S. P. Khanna, E. H. Linfield, and A. G. Davies, “Coherent sampling of active mode-locked terahertz quantum cascade lasers and frequency synthesis,” Nature Photon.5, 306–313 (2011).
[CrossRef]

Rees, P.

P. Spencer, P. Rees, and I. Pierce, Unlocking Dynamical Diversity: Optical Feedback Effects on Semiconductor Lasers (John Wiley & Sons, 2005), chap. 2: Theoretical Analysis.

Reno, J. L.

A. W. M. Lee, T.-Y. Kao, D. Burghoff, Q. Hu, and J. L. Reno, “Terahertz tomography using quantum-cascade lasers,” Opt. Lett.37, 217–219 (2012).
[CrossRef] [PubMed]

A. W. Lee, Q. Qin, S. Kumar, B. S. Williams, Q. Hu, and J. L. Reno, “Real-time terahertz imaging over a standoff distance (≫25 meters),” Appl. Phys. Lett.89, 141125–141125 (2006).
[CrossRef]

Reuter, M.

S. Wietzke, C. Jansen, M. Reuter, T. Jung, D. Kraft, S. Chatterjee, B. Fischer, and M. Koch, “Terahertz spectroscopy on polymers: A review of morphological studies,” J. Mol. Struct.1006, 41–51 (2011).
[CrossRef]

Richter, H.

H.-W. Hubers, S. Pavlov, H. Richter, A. Semenov, L. Mahler, A. Tredicucci, H. Beere, and D. Ritchie, “High-resolution gas phase spectroscopy with a distributed feedback terahertz quantum cascade laser,” Appl. Phys. Lett.89, 061115 (2006).
[CrossRef]

Rio, P.

Y. L. Lim, K. Bertling, P. Rio, J. Tucker, and A. Rakic, “Displacement and distance measurement using the change in junction voltage across a laser diode due to the self-mixing effect,” in Photonics: Design, Technology, and Packaging II, D. Abbott, Y. S. Kivshar, H. H. Rubinsztein-Dunlop, and S. Fan, eds., Proc. SPIE 6038, 60381O-1 (2006).

Ritchie, D.

S. Barbieri, P. Gellie, G. Santarelli, L. Ding, W. Maineult, C. Sirtori, R. Colombelli, H. Beere, and D. Ritchie, “Phase-locking of a 2.7-THz quantum cascade laser to a mode-locked erbium-doped fibre laser,” Nature Photon.4, 636–640 (2010).
[CrossRef]

P. Gellie, S. Barbieri, J.-F. Lampin, P. Filloux, C. Manquest, C. Sirtori, I. Sagnes, S. P. Khanna, E. H. Linfield, A. G. Davies, H. Beere, and D. Ritchie, “Injection-locking of terahertz quantum cascade lasers up to 35 GHz using RF amplitude modulation,” Opt. Express18, 20799–20816 (2010).
[CrossRef] [PubMed]

H.-W. Hubers, S. Pavlov, H. Richter, A. Semenov, L. Mahler, A. Tredicucci, H. Beere, and D. Ritchie, “High-resolution gas phase spectroscopy with a distributed feedback terahertz quantum cascade laser,” Appl. Phys. Lett.89, 061115 (2006).
[CrossRef]

G. Scalari, L. Ajili, J. Faist, H. Beere, E. Linfield, D. Ritchie, and G. Davies, “Far-infrared (λ= 87 μm) bound-to-continuum quantum-cascade lasers operating up to 90 K,” Appl. Phys. Lett.82, 3165–3167 (2003).
[CrossRef]

Ritchie, D. A.

R. P. Green, J. H. Xu, L. Mahler, A. Tredicucci, F. Beltram, G. Giuliani, H. E. Beere, and D. A. Ritchie, “Linewidth enhancement factor of terahertz quantum cascade lasers,” Appl. Phys. Lett.92, 071106 (2008).
[CrossRef]

S. Barbieri, J. Alton, H. E. Beere, J. Fowler, E. H. Linfield, and D. A. Ritchie, “2.9 THz quantum cascade lasers operating up to 70 K in continuous wave,” Appl. Phys. Lett.85, 1674 (2004).
[CrossRef]

R. Köhler, A. Tredicucci, F. Beltram, H. E. Beere, E. H. Linfield, A. G. Davies, D. A. Ritchie, R. C. Iotti, and F. Rossi, “Terahertz semiconductor-heterostructure laser,” Nature417, 156–159 (2002).
[CrossRef] [PubMed]

Rossi, F.

R. Köhler, A. Tredicucci, F. Beltram, H. E. Beere, E. H. Linfield, A. G. Davies, D. A. Ritchie, R. C. Iotti, and F. Rossi, “Terahertz semiconductor-heterostructure laser,” Nature417, 156–159 (2002).
[CrossRef] [PubMed]

Saat, N. K.

Sagnes, I.

Saito, S.

H. Shimosato, M. Ashida, T. Itoh, S. Saito, and K. Sakai, “Ultrabroadband detection of terahertz radiation from 0.1 to 100 THz with photoconductive antenna,” in “Ultrafast Optics V,” (Springer, 2007), pp. 317–323.
[CrossRef]

Sakai, K.

H. Shimosato, M. Ashida, T. Itoh, S. Saito, and K. Sakai, “Ultrabroadband detection of terahertz radiation from 0.1 to 100 THz with photoconductive antenna,” in “Ultrafast Optics V,” (Springer, 2007), pp. 317–323.
[CrossRef]

Salih, M.

Santarelli, G.

M. Ravaro, V. Jagtap, G. Santarelli, C. Sirtori, L. Li, S. Khanna, E. Linfield, and S. Barbieri, “Continuous-wave coherent imaging with terahertz quantum cascade lasers using electro-optic harmonic sampling,” Appl. Phys. Lett.102, 091107 (2013).
[CrossRef]

M. Ravaro, S. Barbieri, G. Santarelli, V. Jagtap, C. Manquest, C. Sirtori, S. Khanna, and E. Linfield, “Measurement of the intrinsic linewidth of terahertz quantum cascade lasers using a near-infrared frequency comb,” Opt. Express20, 25654–25661 (2012).
[CrossRef] [PubMed]

S. Barbieri, M. Ravaro, P. Gellie, G. Santarelli, C. Manquest, C. Sirtori, S. P. Khanna, E. H. Linfield, and A. G. Davies, “Coherent sampling of active mode-locked terahertz quantum cascade lasers and frequency synthesis,” Nature Photon.5, 306–313 (2011).
[CrossRef]

S. Barbieri, P. Gellie, G. Santarelli, L. Ding, W. Maineult, C. Sirtori, R. Colombelli, H. Beere, and D. Ritchie, “Phase-locking of a 2.7-THz quantum cascade laser to a mode-locked erbium-doped fibre laser,” Nature Photon.4, 636–640 (2010).
[CrossRef]

Scalari, G.

G. Scalari, L. Ajili, J. Faist, H. Beere, E. Linfield, D. Ritchie, and G. Davies, “Far-infrared (λ= 87 μm) bound-to-continuum quantum-cascade lasers operating up to 90 K,” Appl. Phys. Lett.82, 3165–3167 (2003).
[CrossRef]

Scalise, L.

T. Bosch, C. Bès, L. Scalise, and G. Plantier, Encyclopedia of Sensors (American Scientific Publishers, 2006), chap. Optical feedback interferometry, pp. 1–20.

Semenov, A.

H.-W. Hubers, S. Pavlov, H. Richter, A. Semenov, L. Mahler, A. Tredicucci, H. Beere, and D. Ritchie, “High-resolution gas phase spectroscopy with a distributed feedback terahertz quantum cascade laser,” Appl. Phys. Lett.89, 061115 (2006).
[CrossRef]

Shaukat, M. U.

Shimosato, H.

H. Shimosato, M. Ashida, T. Itoh, S. Saito, and K. Sakai, “Ultrabroadband detection of terahertz radiation from 0.1 to 100 THz with photoconductive antenna,” in “Ultrafast Optics V,” (Springer, 2007), pp. 317–323.
[CrossRef]

Sirtori, C.

M. Ravaro, V. Jagtap, G. Santarelli, C. Sirtori, L. Li, S. Khanna, E. Linfield, and S. Barbieri, “Continuous-wave coherent imaging with terahertz quantum cascade lasers using electro-optic harmonic sampling,” Appl. Phys. Lett.102, 091107 (2013).
[CrossRef]

M. Ravaro, S. Barbieri, G. Santarelli, V. Jagtap, C. Manquest, C. Sirtori, S. Khanna, and E. Linfield, “Measurement of the intrinsic linewidth of terahertz quantum cascade lasers using a near-infrared frequency comb,” Opt. Express20, 25654–25661 (2012).
[CrossRef] [PubMed]

S. Barbieri, M. Ravaro, P. Gellie, G. Santarelli, C. Manquest, C. Sirtori, S. P. Khanna, E. H. Linfield, and A. G. Davies, “Coherent sampling of active mode-locked terahertz quantum cascade lasers and frequency synthesis,” Nature Photon.5, 306–313 (2011).
[CrossRef]

S. Barbieri, P. Gellie, G. Santarelli, L. Ding, W. Maineult, C. Sirtori, R. Colombelli, H. Beere, and D. Ritchie, “Phase-locking of a 2.7-THz quantum cascade laser to a mode-locked erbium-doped fibre laser,” Nature Photon.4, 636–640 (2010).
[CrossRef]

P. Gellie, S. Barbieri, J.-F. Lampin, P. Filloux, C. Manquest, C. Sirtori, I. Sagnes, S. P. Khanna, E. H. Linfield, A. G. Davies, H. Beere, and D. Ritchie, “Injection-locking of terahertz quantum cascade lasers up to 35 GHz using RF amplitude modulation,” Opt. Express18, 20799–20816 (2010).
[CrossRef] [PubMed]

Spencer, P.

P. Spencer, P. Rees, and I. Pierce, Unlocking Dynamical Diversity: Optical Feedback Effects on Semiconductor Lasers (John Wiley & Sons, 2005), chap. 2: Theoretical Analysis.

Tamosiunas, V.

Tani, M.

P. Han, M. Tani, M. Usami, S. Kono, R. Kersting, and X.-C. Zhang, “A direct comparison between terahertz time-domain spectroscopy and far-infrared fourier transform spectroscopy,” J. Appl. Phys.89, 2357–2359 (2001).
[CrossRef]

Taschin, A.

M. S. Vitiello, L. Consolino, S. Bartalini, A. Taschin, A. Tredicucci, M. Inguscio, and P. De Natale, “Quantum-limited frequency fluctuations in a terahertz laser,” Nat. Photonics6, 525–528 (2012).
[CrossRef]

Termkoa, K.

Tonouchi, M.

M. Tonouchi, “Cutting-edge terahertz technology,” Nature Photon.1, 97–105 (2007).
[CrossRef]

Tredicucci, A.

M. S. Vitiello, L. Consolino, S. Bartalini, A. Taschin, A. Tredicucci, M. Inguscio, and P. De Natale, “Quantum-limited frequency fluctuations in a terahertz laser,” Nat. Photonics6, 525–528 (2012).
[CrossRef]

R. P. Green, J. H. Xu, L. Mahler, A. Tredicucci, F. Beltram, G. Giuliani, H. E. Beere, and D. A. Ritchie, “Linewidth enhancement factor of terahertz quantum cascade lasers,” Appl. Phys. Lett.92, 071106 (2008).
[CrossRef]

H.-W. Hubers, S. Pavlov, H. Richter, A. Semenov, L. Mahler, A. Tredicucci, H. Beere, and D. Ritchie, “High-resolution gas phase spectroscopy with a distributed feedback terahertz quantum cascade laser,” Appl. Phys. Lett.89, 061115 (2006).
[CrossRef]

R. Köhler, A. Tredicucci, F. Beltram, H. E. Beere, E. H. Linfield, A. G. Davies, D. A. Ritchie, R. C. Iotti, and F. Rossi, “Terahertz semiconductor-heterostructure laser,” Nature417, 156–159 (2002).
[CrossRef] [PubMed]

Tucker, J.

Y. L. Lim, K. Bertling, P. Rio, J. Tucker, and A. Rakic, “Displacement and distance measurement using the change in junction voltage across a laser diode due to the self-mixing effect,” in Photonics: Design, Technology, and Packaging II, D. Abbott, Y. S. Kivshar, H. H. Rubinsztein-Dunlop, and S. Fan, eds., Proc. SPIE 6038, 60381O-1 (2006).

Twieg, R.

P. Cunningham, N. Valdes, F. Vallejo, L. Hayden, B. Polishak, X. Zhou, J. Luo, A. Jen, J. Williams, and R. Twieg, “Broadband terahertz characterization of the refractive index and absorption of some important polymeric and organic electro-optic materials,” J. Appl. Phys.109, 043505–043505 (2011).
[CrossRef]

Unterrainer, K.

Upadhya, P. C.

Usami, M.

P. Han, M. Tani, M. Usami, S. Kono, R. Kersting, and X.-C. Zhang, “A direct comparison between terahertz time-domain spectroscopy and far-infrared fourier transform spectroscopy,” J. Appl. Phys.89, 2357–2359 (2001).
[CrossRef]

Valavanis, A.

P. Dean, Y. L. Lim, A. Valavanis, R. Kliese, M. Nikolić, S. P. Khanna, M. Lachab, D. Indjin, Z. Ikonić, P. Harrison, A. D. Rakić, E. H. Linfield, and A. G. Davies, “Terahertz imaging through self-mixing in a quantum cascade laser,” Opt. Lett.36, 2587–2589 (2011).
[CrossRef] [PubMed]

Y. L. Lim, P. Dean, M. Nikolić, R. Kliese, S. P. Khanna, M. Lachab, A. Valavanis, D. Indjin, Z. Ikonić, P. Harrison, E. H. Linfield, A. G. Davies, S. J. Wilson, and A. D. Rakić, “Demonstration of a self-mixing displacement sensor based on terahertz quantum cascade lasers,” Appl. Phys. Lett.99, 081108 (2011).
[CrossRef]

Valdes, N.

P. Cunningham, N. Valdes, F. Vallejo, L. Hayden, B. Polishak, X. Zhou, J. Luo, A. Jen, J. Williams, and R. Twieg, “Broadband terahertz characterization of the refractive index and absorption of some important polymeric and organic electro-optic materials,” J. Appl. Phys.109, 043505–043505 (2011).
[CrossRef]

Vallejo, F.

P. Cunningham, N. Valdes, F. Vallejo, L. Hayden, B. Polishak, X. Zhou, J. Luo, A. Jen, J. Williams, and R. Twieg, “Broadband terahertz characterization of the refractive index and absorption of some important polymeric and organic electro-optic materials,” J. Appl. Phys.109, 043505–043505 (2011).
[CrossRef]

Vangala, S.

Vitiello, M. S.

M. S. Vitiello, L. Consolino, S. Bartalini, A. Taschin, A. Tredicucci, M. Inguscio, and P. De Natale, “Quantum-limited frequency fluctuations in a terahertz laser,” Nat. Photonics6, 525–528 (2012).
[CrossRef]

Waldman, J.

Wietzke, S.

S. Wietzke, C. Jansen, M. Reuter, T. Jung, D. Kraft, S. Chatterjee, B. Fischer, and M. Koch, “Terahertz spectroscopy on polymers: A review of morphological studies,” J. Mol. Struct.1006, 41–51 (2011).
[CrossRef]

Williams, B. S.

A. W. Lee, Q. Qin, S. Kumar, B. S. Williams, Q. Hu, and J. L. Reno, “Real-time terahertz imaging over a standoff distance (≫25 meters),” Appl. Phys. Lett.89, 141125–141125 (2006).
[CrossRef]

Williams, J.

P. Cunningham, N. Valdes, F. Vallejo, L. Hayden, B. Polishak, X. Zhou, J. Luo, A. Jen, J. Williams, and R. Twieg, “Broadband terahertz characterization of the refractive index and absorption of some important polymeric and organic electro-optic materials,” J. Appl. Phys.109, 043505–043505 (2011).
[CrossRef]

Wilson, S. J.

Y. L. Lim, P. Dean, M. Nikolić, R. Kliese, S. P. Khanna, M. Lachab, A. Valavanis, D. Indjin, Z. Ikonić, P. Harrison, E. H. Linfield, A. G. Davies, S. J. Wilson, and A. D. Rakić, “Demonstration of a self-mixing displacement sensor based on terahertz quantum cascade lasers,” Appl. Phys. Lett.99, 081108 (2011).
[CrossRef]

Xu, J. H.

R. P. Green, J. H. Xu, L. Mahler, A. Tredicucci, F. Beltram, G. Giuliani, H. E. Beere, and D. A. Ritchie, “Linewidth enhancement factor of terahertz quantum cascade lasers,” Appl. Phys. Lett.92, 071106 (2008).
[CrossRef]

Zhang, X.-C.

X. Lu, N. Karpowicz, Y. Chen, and X.-C. Zhang, “Systematic study of broadband terahertz gas sensor,” Appl. Phys. Lett.93, 261106 (2008).
[CrossRef]

P. Han, M. Tani, M. Usami, S. Kono, R. Kersting, and X.-C. Zhang, “A direct comparison between terahertz time-domain spectroscopy and far-infrared fourier transform spectroscopy,” J. Appl. Phys.89, 2357–2359 (2001).
[CrossRef]

Zheng, X.

X. Zheng, C. V. McLaughlin, P. Cunningham, and L. M. Hayden, “Organic broadband terahertz sources and sensors,” J. Nanoelectron. Optoelectron.2, 58–76 (2007).
[CrossRef]

Zhou, X.

P. Cunningham, N. Valdes, F. Vallejo, L. Hayden, B. Polishak, X. Zhou, J. Luo, A. Jen, J. Williams, and R. Twieg, “Broadband terahertz characterization of the refractive index and absorption of some important polymeric and organic electro-optic materials,” J. Appl. Phys.109, 043505–043505 (2011).
[CrossRef]

Appl. Opt. (1)

Appl. Phys. Lett. (10)

X. Lu, N. Karpowicz, Y. Chen, and X.-C. Zhang, “Systematic study of broadband terahertz gas sensor,” Appl. Phys. Lett.93, 261106 (2008).
[CrossRef]

A. W. Lee, Q. Qin, S. Kumar, B. S. Williams, Q. Hu, and J. L. Reno, “Real-time terahertz imaging over a standoff distance (≫25 meters),” Appl. Phys. Lett.89, 141125–141125 (2006).
[CrossRef]

H.-W. Hubers, S. Pavlov, H. Richter, A. Semenov, L. Mahler, A. Tredicucci, H. Beere, and D. Ritchie, “High-resolution gas phase spectroscopy with a distributed feedback terahertz quantum cascade laser,” Appl. Phys. Lett.89, 061115 (2006).
[CrossRef]

M. Ravaro, V. Jagtap, G. Santarelli, C. Sirtori, L. Li, S. Khanna, E. Linfield, and S. Barbieri, “Continuous-wave coherent imaging with terahertz quantum cascade lasers using electro-optic harmonic sampling,” Appl. Phys. Lett.102, 091107 (2013).
[CrossRef]

C. V. McLaughlin, L. M. Hayden, B. Polishak, S. Huang, J. Luo, T.-D. Kim, and A. K.-Y. Jen, “Wideband 15 THz response using organic electro-optic polymer emitter-sensor pairs at telecommunication wavelengths,” Appl. Phys. Lett.92, 151107 (2008).
[CrossRef]

G. Scalari, L. Ajili, J. Faist, H. Beere, E. Linfield, D. Ritchie, and G. Davies, “Far-infrared (λ= 87 μm) bound-to-continuum quantum-cascade lasers operating up to 90 K,” Appl. Phys. Lett.82, 3165–3167 (2003).
[CrossRef]

D. Indjin, P. Harrison, R. Kelsall, and Z. Ikonić, “Mechanisms of temperature performance degradation in terahertz quantum-cascade lasers,” Appl. Phys. Lett.82, 1347–1349 (2003).
[CrossRef]

R. P. Green, J. H. Xu, L. Mahler, A. Tredicucci, F. Beltram, G. Giuliani, H. E. Beere, and D. A. Ritchie, “Linewidth enhancement factor of terahertz quantum cascade lasers,” Appl. Phys. Lett.92, 071106 (2008).
[CrossRef]

Y. L. Lim, P. Dean, M. Nikolić, R. Kliese, S. P. Khanna, M. Lachab, A. Valavanis, D. Indjin, Z. Ikonić, P. Harrison, E. H. Linfield, A. G. Davies, S. J. Wilson, and A. D. Rakić, “Demonstration of a self-mixing displacement sensor based on terahertz quantum cascade lasers,” Appl. Phys. Lett.99, 081108 (2011).
[CrossRef]

S. Barbieri, J. Alton, H. E. Beere, J. Fowler, E. H. Linfield, and D. A. Ritchie, “2.9 THz quantum cascade lasers operating up to 70 K in continuous wave,” Appl. Phys. Lett.85, 1674 (2004).
[CrossRef]

Appl. Spectrosc. (1)

IEEE J. Quantum Electron. (3)

S. Donati, “Responsivity and noise of self-mixing photodetection schemes,” IEEE J. Quantum Electron.47, 1428–1433 (2011).
[CrossRef]

G. Plantier, C. Bès, and T. Bosch, “Behavioral model of a self-mixing laser diode sensor,” IEEE J. Quantum Electron.41, 1157–1167 (2005).
[CrossRef]

R. Lang and K. Kobayashi, “External optical feedback effects on semiconductor injection laser properties,” IEEE J. Quantum Electron.16, 347–355 (1980).
[CrossRef]

IEEE J. Sel. Top. Quantum Electron. (1)

L. Duvillaret, F. Garet, and J.-L. Coutaz, “A reliable method for extraction of material parameters in terahertz time-domain spectroscopy,” IEEE J. Sel. Top. Quantum Electron.2, 739–746 (1996).
[CrossRef]

IEEE Sens. J. (1)

M. Naftaly, “Metrology issues and solutions in THz time-domain spectroscopy: Noise, errors, calibration,” IEEE Sens. J.13, 8–17 (2013).
[CrossRef]

J. Appl. Phys. (2)

P. Han, M. Tani, M. Usami, S. Kono, R. Kersting, and X.-C. Zhang, “A direct comparison between terahertz time-domain spectroscopy and far-infrared fourier transform spectroscopy,” J. Appl. Phys.89, 2357–2359 (2001).
[CrossRef]

P. Cunningham, N. Valdes, F. Vallejo, L. Hayden, B. Polishak, X. Zhou, J. Luo, A. Jen, J. Williams, and R. Twieg, “Broadband terahertz characterization of the refractive index and absorption of some important polymeric and organic electro-optic materials,” J. Appl. Phys.109, 043505–043505 (2011).
[CrossRef]

J. Korean Phys. Soc. (1)

Y.-S. Jin, G.-J. Kim, and S.-G. Jeon, “Terahertz dielectric properties of polymers,” J. Korean Phys. Soc.49, 513–517 (2006).

J. Mol. Struct. (1)

S. Wietzke, C. Jansen, M. Reuter, T. Jung, D. Kraft, S. Chatterjee, B. Fischer, and M. Koch, “Terahertz spectroscopy on polymers: A review of morphological studies,” J. Mol. Struct.1006, 41–51 (2011).
[CrossRef]

J. Nanoelectron. Optoelectron. (1)

X. Zheng, C. V. McLaughlin, P. Cunningham, and L. M. Hayden, “Organic broadband terahertz sources and sensors,” J. Nanoelectron. Optoelectron.2, 58–76 (2007).
[CrossRef]

J. Opt. A: Pure Appl. Opt. (1)

G. Giuliani, M. Norgia, S. Donati, and T. Bosch, “Laser diode self-mixing technique for sensing applications,” J. Opt. A: Pure Appl. Opt.4, S283–S294 (2002).
[CrossRef]

Laser Photon. Rev. (2)

P. U. Jepsen, D. G. Cooke, and M. Koch, “Terahertz spectroscopy and imaging — Modern techniques and applications,” Laser Photon. Rev.5, 124–166 (2011).
[CrossRef]

S. Donati, “Developing self-mixing interferometry for instrumentation and measurements,” Laser Photon. Rev.6, 393–417 (2012).
[CrossRef]

Mater. Today (1)

A. G. Davies, A. D. Burnett, W. Fan, E. H. Linfield, and J. E. Cunningham, “Terahertz spectroscopy of explosives and drugs,” Mater. Today11, 18–26 (2008).
[CrossRef]

Nat. Photonics (1)

M. S. Vitiello, L. Consolino, S. Bartalini, A. Taschin, A. Tredicucci, M. Inguscio, and P. De Natale, “Quantum-limited frequency fluctuations in a terahertz laser,” Nat. Photonics6, 525–528 (2012).
[CrossRef]

Nature (1)

R. Köhler, A. Tredicucci, F. Beltram, H. E. Beere, E. H. Linfield, A. G. Davies, D. A. Ritchie, R. C. Iotti, and F. Rossi, “Terahertz semiconductor-heterostructure laser,” Nature417, 156–159 (2002).
[CrossRef] [PubMed]

Nature Photon. (3)

S. Barbieri, P. Gellie, G. Santarelli, L. Ding, W. Maineult, C. Sirtori, R. Colombelli, H. Beere, and D. Ritchie, “Phase-locking of a 2.7-THz quantum cascade laser to a mode-locked erbium-doped fibre laser,” Nature Photon.4, 636–640 (2010).
[CrossRef]

M. Tonouchi, “Cutting-edge terahertz technology,” Nature Photon.1, 97–105 (2007).
[CrossRef]

S. Barbieri, M. Ravaro, P. Gellie, G. Santarelli, C. Manquest, C. Sirtori, S. P. Khanna, E. H. Linfield, and A. G. Davies, “Coherent sampling of active mode-locked terahertz quantum cascade lasers and frequency synthesis,” Nature Photon.5, 306–313 (2011).
[CrossRef]

Opt. Express (7)

J. Darmo, V. Tamosiunas, G. Fasching, J. Kröll, K. Unterrainer, M. Beck, M. Giovannini, J. Faist, C. Kremser, and P. Debbage, “Imaging with a Terahertz quantum cascade laser,” Opt. Express12, 1879–1884 (2004).
[CrossRef] [PubMed]

M. Ravaro, S. Barbieri, G. Santarelli, V. Jagtap, C. Manquest, C. Sirtori, S. Khanna, and E. Linfield, “Measurement of the intrinsic linewidth of terahertz quantum cascade lasers using a near-infrared frequency comb,” Opt. Express20, 25654–25661 (2012).
[CrossRef] [PubMed]

N. Laman, S. S. Harsha, D. Grischkowsky, and J. S. Melinger, “7 GHz resolution waveguide THz spectroscopy of explosives related solids showing new features,” Opt. Express16, 4094–4105 (2008).
[CrossRef] [PubMed]

P. Dean, M. U. Shaukat, S. P. Khanna, S. Chakraborty, M. Lachab, A. Burnett, G. Davies, and E. H. Linfield, “Absorption-sensitive diffuse reflection imaging of concealed powders using a terahertz quantum cascade laser,” Opt. Express16, 5997–6007 (2008).
[CrossRef] [PubMed]

P. Dean, N. K. Saat, S. P. Khanna, M. Salih, A. Burnett, J. Cunningham, E. H. Linfield, and A. G. Davies, “Dual-frequency imaging using an electrically tunable terahertz quantum cascade laser,” Opt. Express17, 20631–20641 (2009).
[CrossRef] [PubMed]

A. A. Danylov, T. M. Goyette, J. Waldman, M. J. Coulombe, A. J. Gatesman, R. H. Giles, X. Qian, N. Chandrayan, S. Vangala, K. Termkoa, W. D. Goodhue, and W. E. Nixon, “Terahertz inverse synthetic aperture radar (ISAR) imaging with a quantum cascade laser transmitter,” Opt. Express18, 16264–16272 (2010).
[CrossRef] [PubMed]

P. Gellie, S. Barbieri, J.-F. Lampin, P. Filloux, C. Manquest, C. Sirtori, I. Sagnes, S. P. Khanna, E. H. Linfield, A. G. Davies, H. Beere, and D. Ritchie, “Injection-locking of terahertz quantum cascade lasers up to 35 GHz using RF amplitude modulation,” Opt. Express18, 20799–20816 (2010).
[CrossRef] [PubMed]

Opt. Lett. (3)

Physica E: Low Dimens. Syst. Nanostruct. (1)

S. P. Khanna, S. Chakraborty, M. Lachab, N. M. Hinchcliffe, E. H. Linfield, and A. G. Davies, “The growth and measurement of terahertz quantum cascade lasers,” Physica E: Low Dimens. Syst. Nanostruct.40, 1859–1861 (2008).
[CrossRef]

Rep. Prog. Phys. (1)

W. L. Chan, J. Deibel, and D. M. Mittleman, “Imaging with terahertz radiation,” Rep. Prog. Phys.70, 1325 (2007).
[CrossRef]

Other (7)

H. Shimosato, M. Ashida, T. Itoh, S. Saito, and K. Sakai, “Ultrabroadband detection of terahertz radiation from 0.1 to 100 THz with photoconductive antenna,” in “Ultrafast Optics V,” (Springer, 2007), pp. 317–323.
[CrossRef]

T. Bosch, C. Bès, L. Scalise, and G. Plantier, Encyclopedia of Sensors (American Scientific Publishers, 2006), chap. Optical feedback interferometry, pp. 1–20.

Y. L. Lim, K. Bertling, P. Rio, J. Tucker, and A. Rakic, “Displacement and distance measurement using the change in junction voltage across a laser diode due to the self-mixing effect,” in Photonics: Design, Technology, and Packaging II, D. Abbott, Y. S. Kivshar, H. H. Rubinsztein-Dunlop, and S. Fan, eds., Proc. SPIE 6038, 60381O-1 (2006).

G. Bryant, Principles of microwave measurements(P. Peregrinus Ltd. on behalf of the Institution of Electrical Engineers, 1993).
[CrossRef]

K. Petermann, Laser diode modulation and noise, 3rd ed. (Springer, 1991).

G. Giuliani and S. Donati, Unlocking Dynamical Diversity: Optical Feedback Effects on Semiconductor Lasers (John Wiley & Sons, 2005), chap. 7: Laser Interferometry.

P. Spencer, P. Rees, and I. Pierce, Unlocking Dynamical Diversity: Optical Feedback Effects on Semiconductor Lasers (John Wiley & Sons, 2005), chap. 2: Theoretical Analysis.

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Figures (3)

Fig. 1
Fig. 1

Schematic diagram showing an intensity, and frequency modulated, self-mixing interferometer with representative waveforms in the time domain. (a) A laser with an external target at distance Lext from the exit facet of the laser. (b) Self-mixing signal observed through variation in laser terminal voltage as a function of time. Broken line: reference slope. Solid line: typical voltage signal. (c) Single period T of the self-mixing signal showing effect of increasing refractive index n of the target. The waveform narrows with increasing n, and the peak shifts to right. (d) Effect of increasing extinction coefficient k of the target. This mainly translates the waveform to the right.

Fig. 2
Fig. 2

Schematic diagram of the experimental apparatus used for target measurements. (a) Current stimulus signal; the current range was selected to sweep the laser frequency through three external cavity resonances in the region where the laser was most sensitive to optical feedback. (b) Corresponding voltage signal measured across the laser terminals. For illustrative purposes, the magnitude of the self-mixing signal has been increased ten-fold. The voltage signal shown is typical for this set-up. (c) The QCL is driven by a sawtooth current signal and the QCL terminal voltage variations are acquired using a PC-based data acquisition card (PC DAQ). A pair of parabolic mirrors focusses the beam onto the remote target containing materials under test, mounted on a computer-controlled translation stage. The six-dot triangular pattern was used for target orientation.

Fig. 3
Fig. 3

Targets, images, and exemplar time-domain traces. (a) Photograph of the front surface of the target. The three circular regions are materials under test embedded in an aluminium holder. Yellow — PA6. Green — PVC. Red — POM. Representative purple line of raster scan across PVC and POM is elaborated upon in (b). (b) Two-dimensional representation of time domain self-mixing signals acquired along representative line in (a), each showing three fringes. The vertical axis represents the temporal evolution of the signal whilst horizontal axis shows their spatial dependence. (c) Amplitude-like Image: Pseudo-colour plot representing the effective aggregate difference between the time domain trace relative to the reference slope. (d) Phase-like Image: Pseudo-colour plot based on the temporal location of the representative peak of the self-mixing signal relative to the edge of the modulation waveform. (e) Representative time domain waveforms for one spatial pixel on the target per material (solid lines) with corresponding model fits (broken lines). The common reference slope is removed.

Tables (1)

Tables Icon

Table 1 Results for six materials under test obtained from two different targets compared against reference values from the literature.

Equations (12)

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φ ( t ) = φ 0 + Φ Δ T t θ R ,
φ S φ FB = C sin ( φ FB + arctan α ) ,
V = V 0 + β cos ( φ FB ) ,
R C 1 + α 2 .
R M = a R + b R R A ,
θ R M = a θ + b θ θ R A ,
R 1 M = a R + b R R 1 A ,
R 2 M = a R + b R R 2 A ,
θ R , 1 M = a θ + b θ θ R , 1 A ,
θ R , 2 M = a θ + b θ θ R , 2 A .
n = 1 R 1 + R 2 R cos ( θ R ) ,
k = 2 R sin ( θ R ) 1 + R 2 R cos ( θ R ) .

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