Abstract

We present a technique for enhancing the light output power of quantum cascade lasers (QCLs) by tilting of the front facet, which leads to a change of the modal reflectivity, resulting in an asymmetric light intensity distribution along the laser cavity. This asymmetry provides most of the light being emitted through one facet of the laser. An experimental study of threshold current, slope efficiency and light output power as a function of the front facet angles were performed and compared to conventional QCLs. The lasers with a front facet angle of 8° shows a 20% improved power output from the front facet.

© 2013 OSA

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, “Quantum Cascade Laser,” Science264(5158), 553–556 (1994).
    [CrossRef] [PubMed]
  2. S. Kumar, “Recent progress in Terahertz Quantum Cascade Lasers,” IEEE J. Quantum Electron.17(1), 38–47 (2011).
    [CrossRef]
  3. Y. Yao, A. J. Hoffman, and C. F. Gmachl, “Mid-infrared quantum cascade lasers,” Nat. Photonics6(7), 432–439 (2012).
    [CrossRef]
  4. M. Hannemann, A. Antufjew, K. Borgmann, F. Hempel, T. Ittermann, S. Welzel, K. D. Weltmann, H. Völzke, and J. Röpcke, “Influence of age and sex in exhaled breath samples investigated by means of infrared laser absorption spectroscopy,” J. Breath. Res.5(2), 027101 (2011).
    [CrossRef] [PubMed]
  5. F. Capasso, R. Paiella, R. Martini, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, and E. A. Whittaker, “Quantum Cascade Lasers: Ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron.38(6), 511–532 (2002).
    [CrossRef]
  6. G. Wysocki, R. Lewicki, R. F. Curl, F. K. Tittel, L. Diehl, F. Capasso, M. Troccoli, G. Hofler, D. Bour, S. Corzine, R. Maulini, M. Giovannini, and J. Faist, “Widely tunable mode-hop free external cavity quantum cascade lasers for high resolution spectroscopy and chemical sensing,” Appl. Phys. B92(3), 305–311 (2008).
    [CrossRef]
  7. B. Schwarz, P. Reininger, H. Detz, T. Zederbauer, A. M. Andrews, S. Kalchmair, W. Schrenk, O. Baumgartner, H. Kosina, and G. Strasser, “A bi-functional quantum cascade device for same frequency lasing and detection,” Appl. Phys. Lett.101(19), 191109 (2012).
    [CrossRef]
  8. R. Maulini, A. Lyakh, A. Tsekoun, R. Go, C. Pflügl, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett.95(15), 151112 (2009).
    [CrossRef]
  9. Y. Bai, S. R. Darvish, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “Optimizing facet coating of quantum cascade lasers for low power consumption,” J. Appl. Phys.109(5), 053103 (2011).
    [CrossRef]
  10. C. E. Zah, J. S. Osinski, C. Caneau, S. G. Menocal, L. A. Reith, J. Salzman, F. K. Shokoohi, and T. P. Lee, “Fabrication and performance of 1.5µm GaInAsP travelling-wave laser amplifiers with angled facets,” Electron. Lett.23(19), 990 (1987).
    [CrossRef]
  11. M. Troccoli, C. Gmachl, F. Capasso, D. L. Sivco, and A. Y. Cho, “Mid-infrared (λ≈7.4 µm) quantum cascade laser amplifier for high power single-mode emission and improved beam quality,” Appl. Phys. Lett.80(22), 4103 (2002).
    [CrossRef]
  12. E. A. Zibik, W. H. Ng, D. G. Revin, L. R. Wilson, J. W. Cockburn, K. M. Groom, and M. Hopkinson, “Broadband 6 µm < λ < 8 µm superluminescent quantum cascade light-emitting diodes,” Appl. Phys. Lett.88(12), 121109 (2006).
    [CrossRef]
  13. Y. Bai, S. Slivken, Q. Y. Lu, N. Bandyopadhyay, and M. Razeghi, “Angled cavity broad area quantum cascade lasers,” Appl. Phys. Lett.101(8), 081106 (2012).
    [CrossRef]
  14. C. F. Lin, “Superluminescent diodes with angled facet etched by chemically assisted ion beam etching,” Electron. Lett.27(11), 968 (1991).
    [CrossRef]
  15. A. O. Dirisu, G. Silva, Z. Liu, C. F. Gmachl, F. J. Towner, J. Bruno, and D. L. Sivco, “Reduction of facet reflectivity of quantum-cascade lasers with subwavelength grating,” IEEE Photon. Technol. Lett.19(4), 221–223 (2007).
    [CrossRef]
  16. N. Yu, R. Blanchard, J. Fan, F. Capasso, T. Edamura, M. Yamanishi, and H. Kan, “Small divergence edge-emitting semiconductor lasers with two-dimensional plasmonic collimators,” Appl. Phys. Lett.93(18), 181101 (2008).
    [CrossRef]
  17. M. Ettenberg, H. S. Sommers, H. Kressel, and H. F. Lockwood, “Control of facet damage in GaAs laser diodes,” Appl. Phys. Lett.18(12), 571 (1971).
    [CrossRef]
  18. K. Petermann, Laser diode modulation and noise, (KTH Scientific Publishers, Dordrecht, 1991), Chap. 2.4. “Lasing characteristic of Fabry-Pérot Type Laser”.
  19. Z. Liu, D. Wasserman, S. S. Howard, A. J. Hoffman, C. F. Gmachl, X. Wang, T. Tanbun-Ek, L. Cheng, and F. S. Choa, “Room-temperature continuous-wave quantum cascade lasers grown by MOCVD without lateral regrowth,” IEEE Photon. Technol. Lett.18(12), 1347–1349 (2006).
    [CrossRef]
  20. E. Mujagić, M. Nobile, H. Detz, W. Schrenk, J. Chen, C. Gmachl, and G. Strasser, “Ring cavity induced threshold reduction in single-mode surface emitting quantum cascade lasers,” Appl. Phys. Lett.96(3), 031111 (2010).
    [CrossRef]
  21. Z. Y. Zhang, I. J. Luxmoore, C. Y. Jin, H. Y. Liu, Q. Jiang, K. M. Groom, D. T. Childs, M. Hopkinson, A. G. Cullis, and R. A. Hogg, “Effect of facet angle on effective facet reflectivity and operating characteristics of quantum dot edge emitting lasers and superluminescent light-emitting diodes,” Appl. Phys. Lett.91(8), 081112 (2007).
    [CrossRef]

2012

Y. Yao, A. J. Hoffman, and C. F. Gmachl, “Mid-infrared quantum cascade lasers,” Nat. Photonics6(7), 432–439 (2012).
[CrossRef]

B. Schwarz, P. Reininger, H. Detz, T. Zederbauer, A. M. Andrews, S. Kalchmair, W. Schrenk, O. Baumgartner, H. Kosina, and G. Strasser, “A bi-functional quantum cascade device for same frequency lasing and detection,” Appl. Phys. Lett.101(19), 191109 (2012).
[CrossRef]

Y. Bai, S. Slivken, Q. Y. Lu, N. Bandyopadhyay, and M. Razeghi, “Angled cavity broad area quantum cascade lasers,” Appl. Phys. Lett.101(8), 081106 (2012).
[CrossRef]

2011

Y. Bai, S. R. Darvish, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “Optimizing facet coating of quantum cascade lasers for low power consumption,” J. Appl. Phys.109(5), 053103 (2011).
[CrossRef]

M. Hannemann, A. Antufjew, K. Borgmann, F. Hempel, T. Ittermann, S. Welzel, K. D. Weltmann, H. Völzke, and J. Röpcke, “Influence of age and sex in exhaled breath samples investigated by means of infrared laser absorption spectroscopy,” J. Breath. Res.5(2), 027101 (2011).
[CrossRef] [PubMed]

S. Kumar, “Recent progress in Terahertz Quantum Cascade Lasers,” IEEE J. Quantum Electron.17(1), 38–47 (2011).
[CrossRef]

2010

E. Mujagić, M. Nobile, H. Detz, W. Schrenk, J. Chen, C. Gmachl, and G. Strasser, “Ring cavity induced threshold reduction in single-mode surface emitting quantum cascade lasers,” Appl. Phys. Lett.96(3), 031111 (2010).
[CrossRef]

2009

R. Maulini, A. Lyakh, A. Tsekoun, R. Go, C. Pflügl, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett.95(15), 151112 (2009).
[CrossRef]

2008

G. Wysocki, R. Lewicki, R. F. Curl, F. K. Tittel, L. Diehl, F. Capasso, M. Troccoli, G. Hofler, D. Bour, S. Corzine, R. Maulini, M. Giovannini, and J. Faist, “Widely tunable mode-hop free external cavity quantum cascade lasers for high resolution spectroscopy and chemical sensing,” Appl. Phys. B92(3), 305–311 (2008).
[CrossRef]

N. Yu, R. Blanchard, J. Fan, F. Capasso, T. Edamura, M. Yamanishi, and H. Kan, “Small divergence edge-emitting semiconductor lasers with two-dimensional plasmonic collimators,” Appl. Phys. Lett.93(18), 181101 (2008).
[CrossRef]

2007

A. O. Dirisu, G. Silva, Z. Liu, C. F. Gmachl, F. J. Towner, J. Bruno, and D. L. Sivco, “Reduction of facet reflectivity of quantum-cascade lasers with subwavelength grating,” IEEE Photon. Technol. Lett.19(4), 221–223 (2007).
[CrossRef]

Z. Y. Zhang, I. J. Luxmoore, C. Y. Jin, H. Y. Liu, Q. Jiang, K. M. Groom, D. T. Childs, M. Hopkinson, A. G. Cullis, and R. A. Hogg, “Effect of facet angle on effective facet reflectivity and operating characteristics of quantum dot edge emitting lasers and superluminescent light-emitting diodes,” Appl. Phys. Lett.91(8), 081112 (2007).
[CrossRef]

2006

Z. Liu, D. Wasserman, S. S. Howard, A. J. Hoffman, C. F. Gmachl, X. Wang, T. Tanbun-Ek, L. Cheng, and F. S. Choa, “Room-temperature continuous-wave quantum cascade lasers grown by MOCVD without lateral regrowth,” IEEE Photon. Technol. Lett.18(12), 1347–1349 (2006).
[CrossRef]

E. A. Zibik, W. H. Ng, D. G. Revin, L. R. Wilson, J. W. Cockburn, K. M. Groom, and M. Hopkinson, “Broadband 6 µm < λ < 8 µm superluminescent quantum cascade light-emitting diodes,” Appl. Phys. Lett.88(12), 121109 (2006).
[CrossRef]

2002

M. Troccoli, C. Gmachl, F. Capasso, D. L. Sivco, and A. Y. Cho, “Mid-infrared (λ≈7.4 µm) quantum cascade laser amplifier for high power single-mode emission and improved beam quality,” Appl. Phys. Lett.80(22), 4103 (2002).
[CrossRef]

F. Capasso, R. Paiella, R. Martini, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, and E. A. Whittaker, “Quantum Cascade Lasers: Ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron.38(6), 511–532 (2002).
[CrossRef]

1994

J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, “Quantum Cascade Laser,” Science264(5158), 553–556 (1994).
[CrossRef] [PubMed]

1991

C. F. Lin, “Superluminescent diodes with angled facet etched by chemically assisted ion beam etching,” Electron. Lett.27(11), 968 (1991).
[CrossRef]

1987

C. E. Zah, J. S. Osinski, C. Caneau, S. G. Menocal, L. A. Reith, J. Salzman, F. K. Shokoohi, and T. P. Lee, “Fabrication and performance of 1.5µm GaInAsP travelling-wave laser amplifiers with angled facets,” Electron. Lett.23(19), 990 (1987).
[CrossRef]

1971

M. Ettenberg, H. S. Sommers, H. Kressel, and H. F. Lockwood, “Control of facet damage in GaAs laser diodes,” Appl. Phys. Lett.18(12), 571 (1971).
[CrossRef]

Andrews, A. M.

B. Schwarz, P. Reininger, H. Detz, T. Zederbauer, A. M. Andrews, S. Kalchmair, W. Schrenk, O. Baumgartner, H. Kosina, and G. Strasser, “A bi-functional quantum cascade device for same frequency lasing and detection,” Appl. Phys. Lett.101(19), 191109 (2012).
[CrossRef]

Antufjew, A.

M. Hannemann, A. Antufjew, K. Borgmann, F. Hempel, T. Ittermann, S. Welzel, K. D. Weltmann, H. Völzke, and J. Röpcke, “Influence of age and sex in exhaled breath samples investigated by means of infrared laser absorption spectroscopy,” J. Breath. Res.5(2), 027101 (2011).
[CrossRef] [PubMed]

Bai, Y.

Y. Bai, S. Slivken, Q. Y. Lu, N. Bandyopadhyay, and M. Razeghi, “Angled cavity broad area quantum cascade lasers,” Appl. Phys. Lett.101(8), 081106 (2012).
[CrossRef]

Y. Bai, S. R. Darvish, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “Optimizing facet coating of quantum cascade lasers for low power consumption,” J. Appl. Phys.109(5), 053103 (2011).
[CrossRef]

Bandyopadhyay, N.

Y. Bai, S. Slivken, Q. Y. Lu, N. Bandyopadhyay, and M. Razeghi, “Angled cavity broad area quantum cascade lasers,” Appl. Phys. Lett.101(8), 081106 (2012).
[CrossRef]

Y. Bai, S. R. Darvish, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “Optimizing facet coating of quantum cascade lasers for low power consumption,” J. Appl. Phys.109(5), 053103 (2011).
[CrossRef]

Baumgartner, O.

B. Schwarz, P. Reininger, H. Detz, T. Zederbauer, A. M. Andrews, S. Kalchmair, W. Schrenk, O. Baumgartner, H. Kosina, and G. Strasser, “A bi-functional quantum cascade device for same frequency lasing and detection,” Appl. Phys. Lett.101(19), 191109 (2012).
[CrossRef]

Bethea, C. G.

F. Capasso, R. Paiella, R. Martini, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, and E. A. Whittaker, “Quantum Cascade Lasers: Ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron.38(6), 511–532 (2002).
[CrossRef]

Blanchard, R.

N. Yu, R. Blanchard, J. Fan, F. Capasso, T. Edamura, M. Yamanishi, and H. Kan, “Small divergence edge-emitting semiconductor lasers with two-dimensional plasmonic collimators,” Appl. Phys. Lett.93(18), 181101 (2008).
[CrossRef]

Borgmann, K.

M. Hannemann, A. Antufjew, K. Borgmann, F. Hempel, T. Ittermann, S. Welzel, K. D. Weltmann, H. Völzke, and J. Röpcke, “Influence of age and sex in exhaled breath samples investigated by means of infrared laser absorption spectroscopy,” J. Breath. Res.5(2), 027101 (2011).
[CrossRef] [PubMed]

Bour, D.

G. Wysocki, R. Lewicki, R. F. Curl, F. K. Tittel, L. Diehl, F. Capasso, M. Troccoli, G. Hofler, D. Bour, S. Corzine, R. Maulini, M. Giovannini, and J. Faist, “Widely tunable mode-hop free external cavity quantum cascade lasers for high resolution spectroscopy and chemical sensing,” Appl. Phys. B92(3), 305–311 (2008).
[CrossRef]

Bruno, J.

A. O. Dirisu, G. Silva, Z. Liu, C. F. Gmachl, F. J. Towner, J. Bruno, and D. L. Sivco, “Reduction of facet reflectivity of quantum-cascade lasers with subwavelength grating,” IEEE Photon. Technol. Lett.19(4), 221–223 (2007).
[CrossRef]

Caneau, C.

C. E. Zah, J. S. Osinski, C. Caneau, S. G. Menocal, L. A. Reith, J. Salzman, F. K. Shokoohi, and T. P. Lee, “Fabrication and performance of 1.5µm GaInAsP travelling-wave laser amplifiers with angled facets,” Electron. Lett.23(19), 990 (1987).
[CrossRef]

Capasso, F.

R. Maulini, A. Lyakh, A. Tsekoun, R. Go, C. Pflügl, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett.95(15), 151112 (2009).
[CrossRef]

G. Wysocki, R. Lewicki, R. F. Curl, F. K. Tittel, L. Diehl, F. Capasso, M. Troccoli, G. Hofler, D. Bour, S. Corzine, R. Maulini, M. Giovannini, and J. Faist, “Widely tunable mode-hop free external cavity quantum cascade lasers for high resolution spectroscopy and chemical sensing,” Appl. Phys. B92(3), 305–311 (2008).
[CrossRef]

N. Yu, R. Blanchard, J. Fan, F. Capasso, T. Edamura, M. Yamanishi, and H. Kan, “Small divergence edge-emitting semiconductor lasers with two-dimensional plasmonic collimators,” Appl. Phys. Lett.93(18), 181101 (2008).
[CrossRef]

M. Troccoli, C. Gmachl, F. Capasso, D. L. Sivco, and A. Y. Cho, “Mid-infrared (λ≈7.4 µm) quantum cascade laser amplifier for high power single-mode emission and improved beam quality,” Appl. Phys. Lett.80(22), 4103 (2002).
[CrossRef]

F. Capasso, R. Paiella, R. Martini, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, and E. A. Whittaker, “Quantum Cascade Lasers: Ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron.38(6), 511–532 (2002).
[CrossRef]

J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, “Quantum Cascade Laser,” Science264(5158), 553–556 (1994).
[CrossRef] [PubMed]

Chen, J.

E. Mujagić, M. Nobile, H. Detz, W. Schrenk, J. Chen, C. Gmachl, and G. Strasser, “Ring cavity induced threshold reduction in single-mode surface emitting quantum cascade lasers,” Appl. Phys. Lett.96(3), 031111 (2010).
[CrossRef]

Cheng, L.

Z. Liu, D. Wasserman, S. S. Howard, A. J. Hoffman, C. F. Gmachl, X. Wang, T. Tanbun-Ek, L. Cheng, and F. S. Choa, “Room-temperature continuous-wave quantum cascade lasers grown by MOCVD without lateral regrowth,” IEEE Photon. Technol. Lett.18(12), 1347–1349 (2006).
[CrossRef]

Childs, D. T.

Z. Y. Zhang, I. J. Luxmoore, C. Y. Jin, H. Y. Liu, Q. Jiang, K. M. Groom, D. T. Childs, M. Hopkinson, A. G. Cullis, and R. A. Hogg, “Effect of facet angle on effective facet reflectivity and operating characteristics of quantum dot edge emitting lasers and superluminescent light-emitting diodes,” Appl. Phys. Lett.91(8), 081112 (2007).
[CrossRef]

Cho, A. Y.

M. Troccoli, C. Gmachl, F. Capasso, D. L. Sivco, and A. Y. Cho, “Mid-infrared (λ≈7.4 µm) quantum cascade laser amplifier for high power single-mode emission and improved beam quality,” Appl. Phys. Lett.80(22), 4103 (2002).
[CrossRef]

F. Capasso, R. Paiella, R. Martini, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, and E. A. Whittaker, “Quantum Cascade Lasers: Ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron.38(6), 511–532 (2002).
[CrossRef]

J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, “Quantum Cascade Laser,” Science264(5158), 553–556 (1994).
[CrossRef] [PubMed]

Choa, F. S.

Z. Liu, D. Wasserman, S. S. Howard, A. J. Hoffman, C. F. Gmachl, X. Wang, T. Tanbun-Ek, L. Cheng, and F. S. Choa, “Room-temperature continuous-wave quantum cascade lasers grown by MOCVD without lateral regrowth,” IEEE Photon. Technol. Lett.18(12), 1347–1349 (2006).
[CrossRef]

Cockburn, J. W.

E. A. Zibik, W. H. Ng, D. G. Revin, L. R. Wilson, J. W. Cockburn, K. M. Groom, and M. Hopkinson, “Broadband 6 µm < λ < 8 µm superluminescent quantum cascade light-emitting diodes,” Appl. Phys. Lett.88(12), 121109 (2006).
[CrossRef]

Colombelli, R.

F. Capasso, R. Paiella, R. Martini, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, and E. A. Whittaker, “Quantum Cascade Lasers: Ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron.38(6), 511–532 (2002).
[CrossRef]

Corzine, S.

G. Wysocki, R. Lewicki, R. F. Curl, F. K. Tittel, L. Diehl, F. Capasso, M. Troccoli, G. Hofler, D. Bour, S. Corzine, R. Maulini, M. Giovannini, and J. Faist, “Widely tunable mode-hop free external cavity quantum cascade lasers for high resolution spectroscopy and chemical sensing,” Appl. Phys. B92(3), 305–311 (2008).
[CrossRef]

Cullis, A. G.

Z. Y. Zhang, I. J. Luxmoore, C. Y. Jin, H. Y. Liu, Q. Jiang, K. M. Groom, D. T. Childs, M. Hopkinson, A. G. Cullis, and R. A. Hogg, “Effect of facet angle on effective facet reflectivity and operating characteristics of quantum dot edge emitting lasers and superluminescent light-emitting diodes,” Appl. Phys. Lett.91(8), 081112 (2007).
[CrossRef]

Curl, R. F.

G. Wysocki, R. Lewicki, R. F. Curl, F. K. Tittel, L. Diehl, F. Capasso, M. Troccoli, G. Hofler, D. Bour, S. Corzine, R. Maulini, M. Giovannini, and J. Faist, “Widely tunable mode-hop free external cavity quantum cascade lasers for high resolution spectroscopy and chemical sensing,” Appl. Phys. B92(3), 305–311 (2008).
[CrossRef]

Darvish, S. R.

Y. Bai, S. R. Darvish, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “Optimizing facet coating of quantum cascade lasers for low power consumption,” J. Appl. Phys.109(5), 053103 (2011).
[CrossRef]

Detz, H.

B. Schwarz, P. Reininger, H. Detz, T. Zederbauer, A. M. Andrews, S. Kalchmair, W. Schrenk, O. Baumgartner, H. Kosina, and G. Strasser, “A bi-functional quantum cascade device for same frequency lasing and detection,” Appl. Phys. Lett.101(19), 191109 (2012).
[CrossRef]

E. Mujagić, M. Nobile, H. Detz, W. Schrenk, J. Chen, C. Gmachl, and G. Strasser, “Ring cavity induced threshold reduction in single-mode surface emitting quantum cascade lasers,” Appl. Phys. Lett.96(3), 031111 (2010).
[CrossRef]

Diehl, L.

R. Maulini, A. Lyakh, A. Tsekoun, R. Go, C. Pflügl, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett.95(15), 151112 (2009).
[CrossRef]

G. Wysocki, R. Lewicki, R. F. Curl, F. K. Tittel, L. Diehl, F. Capasso, M. Troccoli, G. Hofler, D. Bour, S. Corzine, R. Maulini, M. Giovannini, and J. Faist, “Widely tunable mode-hop free external cavity quantum cascade lasers for high resolution spectroscopy and chemical sensing,” Appl. Phys. B92(3), 305–311 (2008).
[CrossRef]

Dirisu, A. O.

A. O. Dirisu, G. Silva, Z. Liu, C. F. Gmachl, F. J. Towner, J. Bruno, and D. L. Sivco, “Reduction of facet reflectivity of quantum-cascade lasers with subwavelength grating,” IEEE Photon. Technol. Lett.19(4), 221–223 (2007).
[CrossRef]

Edamura, T.

N. Yu, R. Blanchard, J. Fan, F. Capasso, T. Edamura, M. Yamanishi, and H. Kan, “Small divergence edge-emitting semiconductor lasers with two-dimensional plasmonic collimators,” Appl. Phys. Lett.93(18), 181101 (2008).
[CrossRef]

Ettenberg, M.

M. Ettenberg, H. S. Sommers, H. Kressel, and H. F. Lockwood, “Control of facet damage in GaAs laser diodes,” Appl. Phys. Lett.18(12), 571 (1971).
[CrossRef]

Faist, J.

G. Wysocki, R. Lewicki, R. F. Curl, F. K. Tittel, L. Diehl, F. Capasso, M. Troccoli, G. Hofler, D. Bour, S. Corzine, R. Maulini, M. Giovannini, and J. Faist, “Widely tunable mode-hop free external cavity quantum cascade lasers for high resolution spectroscopy and chemical sensing,” Appl. Phys. B92(3), 305–311 (2008).
[CrossRef]

J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, “Quantum Cascade Laser,” Science264(5158), 553–556 (1994).
[CrossRef] [PubMed]

Fan, J.

N. Yu, R. Blanchard, J. Fan, F. Capasso, T. Edamura, M. Yamanishi, and H. Kan, “Small divergence edge-emitting semiconductor lasers with two-dimensional plasmonic collimators,” Appl. Phys. Lett.93(18), 181101 (2008).
[CrossRef]

Giovannini, M.

G. Wysocki, R. Lewicki, R. F. Curl, F. K. Tittel, L. Diehl, F. Capasso, M. Troccoli, G. Hofler, D. Bour, S. Corzine, R. Maulini, M. Giovannini, and J. Faist, “Widely tunable mode-hop free external cavity quantum cascade lasers for high resolution spectroscopy and chemical sensing,” Appl. Phys. B92(3), 305–311 (2008).
[CrossRef]

Gmachl, C.

E. Mujagić, M. Nobile, H. Detz, W. Schrenk, J. Chen, C. Gmachl, and G. Strasser, “Ring cavity induced threshold reduction in single-mode surface emitting quantum cascade lasers,” Appl. Phys. Lett.96(3), 031111 (2010).
[CrossRef]

M. Troccoli, C. Gmachl, F. Capasso, D. L. Sivco, and A. Y. Cho, “Mid-infrared (λ≈7.4 µm) quantum cascade laser amplifier for high power single-mode emission and improved beam quality,” Appl. Phys. Lett.80(22), 4103 (2002).
[CrossRef]

F. Capasso, R. Paiella, R. Martini, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, and E. A. Whittaker, “Quantum Cascade Lasers: Ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron.38(6), 511–532 (2002).
[CrossRef]

Gmachl, C. F.

Y. Yao, A. J. Hoffman, and C. F. Gmachl, “Mid-infrared quantum cascade lasers,” Nat. Photonics6(7), 432–439 (2012).
[CrossRef]

A. O. Dirisu, G. Silva, Z. Liu, C. F. Gmachl, F. J. Towner, J. Bruno, and D. L. Sivco, “Reduction of facet reflectivity of quantum-cascade lasers with subwavelength grating,” IEEE Photon. Technol. Lett.19(4), 221–223 (2007).
[CrossRef]

Z. Liu, D. Wasserman, S. S. Howard, A. J. Hoffman, C. F. Gmachl, X. Wang, T. Tanbun-Ek, L. Cheng, and F. S. Choa, “Room-temperature continuous-wave quantum cascade lasers grown by MOCVD without lateral regrowth,” IEEE Photon. Technol. Lett.18(12), 1347–1349 (2006).
[CrossRef]

Go, R.

R. Maulini, A. Lyakh, A. Tsekoun, R. Go, C. Pflügl, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett.95(15), 151112 (2009).
[CrossRef]

Groom, K. M.

Z. Y. Zhang, I. J. Luxmoore, C. Y. Jin, H. Y. Liu, Q. Jiang, K. M. Groom, D. T. Childs, M. Hopkinson, A. G. Cullis, and R. A. Hogg, “Effect of facet angle on effective facet reflectivity and operating characteristics of quantum dot edge emitting lasers and superluminescent light-emitting diodes,” Appl. Phys. Lett.91(8), 081112 (2007).
[CrossRef]

E. A. Zibik, W. H. Ng, D. G. Revin, L. R. Wilson, J. W. Cockburn, K. M. Groom, and M. Hopkinson, “Broadband 6 µm < λ < 8 µm superluminescent quantum cascade light-emitting diodes,” Appl. Phys. Lett.88(12), 121109 (2006).
[CrossRef]

Hannemann, M.

M. Hannemann, A. Antufjew, K. Borgmann, F. Hempel, T. Ittermann, S. Welzel, K. D. Weltmann, H. Völzke, and J. Röpcke, “Influence of age and sex in exhaled breath samples investigated by means of infrared laser absorption spectroscopy,” J. Breath. Res.5(2), 027101 (2011).
[CrossRef] [PubMed]

Hempel, F.

M. Hannemann, A. Antufjew, K. Borgmann, F. Hempel, T. Ittermann, S. Welzel, K. D. Weltmann, H. Völzke, and J. Röpcke, “Influence of age and sex in exhaled breath samples investigated by means of infrared laser absorption spectroscopy,” J. Breath. Res.5(2), 027101 (2011).
[CrossRef] [PubMed]

Hoffman, A. J.

Y. Yao, A. J. Hoffman, and C. F. Gmachl, “Mid-infrared quantum cascade lasers,” Nat. Photonics6(7), 432–439 (2012).
[CrossRef]

Z. Liu, D. Wasserman, S. S. Howard, A. J. Hoffman, C. F. Gmachl, X. Wang, T. Tanbun-Ek, L. Cheng, and F. S. Choa, “Room-temperature continuous-wave quantum cascade lasers grown by MOCVD without lateral regrowth,” IEEE Photon. Technol. Lett.18(12), 1347–1349 (2006).
[CrossRef]

Hofler, G.

G. Wysocki, R. Lewicki, R. F. Curl, F. K. Tittel, L. Diehl, F. Capasso, M. Troccoli, G. Hofler, D. Bour, S. Corzine, R. Maulini, M. Giovannini, and J. Faist, “Widely tunable mode-hop free external cavity quantum cascade lasers for high resolution spectroscopy and chemical sensing,” Appl. Phys. B92(3), 305–311 (2008).
[CrossRef]

Hogg, R. A.

Z. Y. Zhang, I. J. Luxmoore, C. Y. Jin, H. Y. Liu, Q. Jiang, K. M. Groom, D. T. Childs, M. Hopkinson, A. G. Cullis, and R. A. Hogg, “Effect of facet angle on effective facet reflectivity and operating characteristics of quantum dot edge emitting lasers and superluminescent light-emitting diodes,” Appl. Phys. Lett.91(8), 081112 (2007).
[CrossRef]

Hopkinson, M.

Z. Y. Zhang, I. J. Luxmoore, C. Y. Jin, H. Y. Liu, Q. Jiang, K. M. Groom, D. T. Childs, M. Hopkinson, A. G. Cullis, and R. A. Hogg, “Effect of facet angle on effective facet reflectivity and operating characteristics of quantum dot edge emitting lasers and superluminescent light-emitting diodes,” Appl. Phys. Lett.91(8), 081112 (2007).
[CrossRef]

E. A. Zibik, W. H. Ng, D. G. Revin, L. R. Wilson, J. W. Cockburn, K. M. Groom, and M. Hopkinson, “Broadband 6 µm < λ < 8 µm superluminescent quantum cascade light-emitting diodes,” Appl. Phys. Lett.88(12), 121109 (2006).
[CrossRef]

Howard, S. S.

Z. Liu, D. Wasserman, S. S. Howard, A. J. Hoffman, C. F. Gmachl, X. Wang, T. Tanbun-Ek, L. Cheng, and F. S. Choa, “Room-temperature continuous-wave quantum cascade lasers grown by MOCVD without lateral regrowth,” IEEE Photon. Technol. Lett.18(12), 1347–1349 (2006).
[CrossRef]

Hutchinson, A. L.

J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, “Quantum Cascade Laser,” Science264(5158), 553–556 (1994).
[CrossRef] [PubMed]

Hwang, H. Y.

F. Capasso, R. Paiella, R. Martini, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, and E. A. Whittaker, “Quantum Cascade Lasers: Ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron.38(6), 511–532 (2002).
[CrossRef]

Ittermann, T.

M. Hannemann, A. Antufjew, K. Borgmann, F. Hempel, T. Ittermann, S. Welzel, K. D. Weltmann, H. Völzke, and J. Röpcke, “Influence of age and sex in exhaled breath samples investigated by means of infrared laser absorption spectroscopy,” J. Breath. Res.5(2), 027101 (2011).
[CrossRef] [PubMed]

Jiang, Q.

Z. Y. Zhang, I. J. Luxmoore, C. Y. Jin, H. Y. Liu, Q. Jiang, K. M. Groom, D. T. Childs, M. Hopkinson, A. G. Cullis, and R. A. Hogg, “Effect of facet angle on effective facet reflectivity and operating characteristics of quantum dot edge emitting lasers and superluminescent light-emitting diodes,” Appl. Phys. Lett.91(8), 081112 (2007).
[CrossRef]

Jin, C. Y.

Z. Y. Zhang, I. J. Luxmoore, C. Y. Jin, H. Y. Liu, Q. Jiang, K. M. Groom, D. T. Childs, M. Hopkinson, A. G. Cullis, and R. A. Hogg, “Effect of facet angle on effective facet reflectivity and operating characteristics of quantum dot edge emitting lasers and superluminescent light-emitting diodes,” Appl. Phys. Lett.91(8), 081112 (2007).
[CrossRef]

Kalchmair, S.

B. Schwarz, P. Reininger, H. Detz, T. Zederbauer, A. M. Andrews, S. Kalchmair, W. Schrenk, O. Baumgartner, H. Kosina, and G. Strasser, “A bi-functional quantum cascade device for same frequency lasing and detection,” Appl. Phys. Lett.101(19), 191109 (2012).
[CrossRef]

Kan, H.

N. Yu, R. Blanchard, J. Fan, F. Capasso, T. Edamura, M. Yamanishi, and H. Kan, “Small divergence edge-emitting semiconductor lasers with two-dimensional plasmonic collimators,” Appl. Phys. Lett.93(18), 181101 (2008).
[CrossRef]

Kosina, H.

B. Schwarz, P. Reininger, H. Detz, T. Zederbauer, A. M. Andrews, S. Kalchmair, W. Schrenk, O. Baumgartner, H. Kosina, and G. Strasser, “A bi-functional quantum cascade device for same frequency lasing and detection,” Appl. Phys. Lett.101(19), 191109 (2012).
[CrossRef]

Kressel, H.

M. Ettenberg, H. S. Sommers, H. Kressel, and H. F. Lockwood, “Control of facet damage in GaAs laser diodes,” Appl. Phys. Lett.18(12), 571 (1971).
[CrossRef]

Kumar, C.

R. Maulini, A. Lyakh, A. Tsekoun, R. Go, C. Pflügl, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett.95(15), 151112 (2009).
[CrossRef]

Kumar, S.

S. Kumar, “Recent progress in Terahertz Quantum Cascade Lasers,” IEEE J. Quantum Electron.17(1), 38–47 (2011).
[CrossRef]

Lee, T. P.

C. E. Zah, J. S. Osinski, C. Caneau, S. G. Menocal, L. A. Reith, J. Salzman, F. K. Shokoohi, and T. P. Lee, “Fabrication and performance of 1.5µm GaInAsP travelling-wave laser amplifiers with angled facets,” Electron. Lett.23(19), 990 (1987).
[CrossRef]

Lewicki, R.

G. Wysocki, R. Lewicki, R. F. Curl, F. K. Tittel, L. Diehl, F. Capasso, M. Troccoli, G. Hofler, D. Bour, S. Corzine, R. Maulini, M. Giovannini, and J. Faist, “Widely tunable mode-hop free external cavity quantum cascade lasers for high resolution spectroscopy and chemical sensing,” Appl. Phys. B92(3), 305–311 (2008).
[CrossRef]

Lin, C. F.

C. F. Lin, “Superluminescent diodes with angled facet etched by chemically assisted ion beam etching,” Electron. Lett.27(11), 968 (1991).
[CrossRef]

Liu, H. C.

F. Capasso, R. Paiella, R. Martini, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, and E. A. Whittaker, “Quantum Cascade Lasers: Ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron.38(6), 511–532 (2002).
[CrossRef]

Liu, H. Y.

Z. Y. Zhang, I. J. Luxmoore, C. Y. Jin, H. Y. Liu, Q. Jiang, K. M. Groom, D. T. Childs, M. Hopkinson, A. G. Cullis, and R. A. Hogg, “Effect of facet angle on effective facet reflectivity and operating characteristics of quantum dot edge emitting lasers and superluminescent light-emitting diodes,” Appl. Phys. Lett.91(8), 081112 (2007).
[CrossRef]

Liu, Z.

A. O. Dirisu, G. Silva, Z. Liu, C. F. Gmachl, F. J. Towner, J. Bruno, and D. L. Sivco, “Reduction of facet reflectivity of quantum-cascade lasers with subwavelength grating,” IEEE Photon. Technol. Lett.19(4), 221–223 (2007).
[CrossRef]

Z. Liu, D. Wasserman, S. S. Howard, A. J. Hoffman, C. F. Gmachl, X. Wang, T. Tanbun-Ek, L. Cheng, and F. S. Choa, “Room-temperature continuous-wave quantum cascade lasers grown by MOCVD without lateral regrowth,” IEEE Photon. Technol. Lett.18(12), 1347–1349 (2006).
[CrossRef]

Lockwood, H. F.

M. Ettenberg, H. S. Sommers, H. Kressel, and H. F. Lockwood, “Control of facet damage in GaAs laser diodes,” Appl. Phys. Lett.18(12), 571 (1971).
[CrossRef]

Lu, Q. Y.

Y. Bai, S. Slivken, Q. Y. Lu, N. Bandyopadhyay, and M. Razeghi, “Angled cavity broad area quantum cascade lasers,” Appl. Phys. Lett.101(8), 081106 (2012).
[CrossRef]

Luxmoore, I. J.

Z. Y. Zhang, I. J. Luxmoore, C. Y. Jin, H. Y. Liu, Q. Jiang, K. M. Groom, D. T. Childs, M. Hopkinson, A. G. Cullis, and R. A. Hogg, “Effect of facet angle on effective facet reflectivity and operating characteristics of quantum dot edge emitting lasers and superluminescent light-emitting diodes,” Appl. Phys. Lett.91(8), 081112 (2007).
[CrossRef]

Lyakh, A.

R. Maulini, A. Lyakh, A. Tsekoun, R. Go, C. Pflügl, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett.95(15), 151112 (2009).
[CrossRef]

Martini, R.

F. Capasso, R. Paiella, R. Martini, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, and E. A. Whittaker, “Quantum Cascade Lasers: Ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron.38(6), 511–532 (2002).
[CrossRef]

Maulini, R.

R. Maulini, A. Lyakh, A. Tsekoun, R. Go, C. Pflügl, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett.95(15), 151112 (2009).
[CrossRef]

G. Wysocki, R. Lewicki, R. F. Curl, F. K. Tittel, L. Diehl, F. Capasso, M. Troccoli, G. Hofler, D. Bour, S. Corzine, R. Maulini, M. Giovannini, and J. Faist, “Widely tunable mode-hop free external cavity quantum cascade lasers for high resolution spectroscopy and chemical sensing,” Appl. Phys. B92(3), 305–311 (2008).
[CrossRef]

Menocal, S. G.

C. E. Zah, J. S. Osinski, C. Caneau, S. G. Menocal, L. A. Reith, J. Salzman, F. K. Shokoohi, and T. P. Lee, “Fabrication and performance of 1.5µm GaInAsP travelling-wave laser amplifiers with angled facets,” Electron. Lett.23(19), 990 (1987).
[CrossRef]

Mujagic, E.

E. Mujagić, M. Nobile, H. Detz, W. Schrenk, J. Chen, C. Gmachl, and G. Strasser, “Ring cavity induced threshold reduction in single-mode surface emitting quantum cascade lasers,” Appl. Phys. Lett.96(3), 031111 (2010).
[CrossRef]

Myers, T. L.

F. Capasso, R. Paiella, R. Martini, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, and E. A. Whittaker, “Quantum Cascade Lasers: Ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron.38(6), 511–532 (2002).
[CrossRef]

Ng, W. H.

E. A. Zibik, W. H. Ng, D. G. Revin, L. R. Wilson, J. W. Cockburn, K. M. Groom, and M. Hopkinson, “Broadband 6 µm < λ < 8 µm superluminescent quantum cascade light-emitting diodes,” Appl. Phys. Lett.88(12), 121109 (2006).
[CrossRef]

Nobile, M.

E. Mujagić, M. Nobile, H. Detz, W. Schrenk, J. Chen, C. Gmachl, and G. Strasser, “Ring cavity induced threshold reduction in single-mode surface emitting quantum cascade lasers,” Appl. Phys. Lett.96(3), 031111 (2010).
[CrossRef]

Osinski, J. S.

C. E. Zah, J. S. Osinski, C. Caneau, S. G. Menocal, L. A. Reith, J. Salzman, F. K. Shokoohi, and T. P. Lee, “Fabrication and performance of 1.5µm GaInAsP travelling-wave laser amplifiers with angled facets,” Electron. Lett.23(19), 990 (1987).
[CrossRef]

Paiella, R.

F. Capasso, R. Paiella, R. Martini, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, and E. A. Whittaker, “Quantum Cascade Lasers: Ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron.38(6), 511–532 (2002).
[CrossRef]

Patel, N.

R. Maulini, A. Lyakh, A. Tsekoun, R. Go, C. Pflügl, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett.95(15), 151112 (2009).
[CrossRef]

Pflügl, C.

R. Maulini, A. Lyakh, A. Tsekoun, R. Go, C. Pflügl, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett.95(15), 151112 (2009).
[CrossRef]

Razeghi, M.

Y. Bai, S. Slivken, Q. Y. Lu, N. Bandyopadhyay, and M. Razeghi, “Angled cavity broad area quantum cascade lasers,” Appl. Phys. Lett.101(8), 081106 (2012).
[CrossRef]

Y. Bai, S. R. Darvish, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “Optimizing facet coating of quantum cascade lasers for low power consumption,” J. Appl. Phys.109(5), 053103 (2011).
[CrossRef]

Reininger, P.

B. Schwarz, P. Reininger, H. Detz, T. Zederbauer, A. M. Andrews, S. Kalchmair, W. Schrenk, O. Baumgartner, H. Kosina, and G. Strasser, “A bi-functional quantum cascade device for same frequency lasing and detection,” Appl. Phys. Lett.101(19), 191109 (2012).
[CrossRef]

Reith, L. A.

C. E. Zah, J. S. Osinski, C. Caneau, S. G. Menocal, L. A. Reith, J. Salzman, F. K. Shokoohi, and T. P. Lee, “Fabrication and performance of 1.5µm GaInAsP travelling-wave laser amplifiers with angled facets,” Electron. Lett.23(19), 990 (1987).
[CrossRef]

Revin, D. G.

E. A. Zibik, W. H. Ng, D. G. Revin, L. R. Wilson, J. W. Cockburn, K. M. Groom, and M. Hopkinson, “Broadband 6 µm < λ < 8 µm superluminescent quantum cascade light-emitting diodes,” Appl. Phys. Lett.88(12), 121109 (2006).
[CrossRef]

Röpcke, J.

M. Hannemann, A. Antufjew, K. Borgmann, F. Hempel, T. Ittermann, S. Welzel, K. D. Weltmann, H. Völzke, and J. Röpcke, “Influence of age and sex in exhaled breath samples investigated by means of infrared laser absorption spectroscopy,” J. Breath. Res.5(2), 027101 (2011).
[CrossRef] [PubMed]

Salzman, J.

C. E. Zah, J. S. Osinski, C. Caneau, S. G. Menocal, L. A. Reith, J. Salzman, F. K. Shokoohi, and T. P. Lee, “Fabrication and performance of 1.5µm GaInAsP travelling-wave laser amplifiers with angled facets,” Electron. Lett.23(19), 990 (1987).
[CrossRef]

Schrenk, W.

B. Schwarz, P. Reininger, H. Detz, T. Zederbauer, A. M. Andrews, S. Kalchmair, W. Schrenk, O. Baumgartner, H. Kosina, and G. Strasser, “A bi-functional quantum cascade device for same frequency lasing and detection,” Appl. Phys. Lett.101(19), 191109 (2012).
[CrossRef]

E. Mujagić, M. Nobile, H. Detz, W. Schrenk, J. Chen, C. Gmachl, and G. Strasser, “Ring cavity induced threshold reduction in single-mode surface emitting quantum cascade lasers,” Appl. Phys. Lett.96(3), 031111 (2010).
[CrossRef]

Schwarz, B.

B. Schwarz, P. Reininger, H. Detz, T. Zederbauer, A. M. Andrews, S. Kalchmair, W. Schrenk, O. Baumgartner, H. Kosina, and G. Strasser, “A bi-functional quantum cascade device for same frequency lasing and detection,” Appl. Phys. Lett.101(19), 191109 (2012).
[CrossRef]

Sergent, A. M.

F. Capasso, R. Paiella, R. Martini, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, and E. A. Whittaker, “Quantum Cascade Lasers: Ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron.38(6), 511–532 (2002).
[CrossRef]

Shokoohi, F. K.

C. E. Zah, J. S. Osinski, C. Caneau, S. G. Menocal, L. A. Reith, J. Salzman, F. K. Shokoohi, and T. P. Lee, “Fabrication and performance of 1.5µm GaInAsP travelling-wave laser amplifiers with angled facets,” Electron. Lett.23(19), 990 (1987).
[CrossRef]

Silva, G.

A. O. Dirisu, G. Silva, Z. Liu, C. F. Gmachl, F. J. Towner, J. Bruno, and D. L. Sivco, “Reduction of facet reflectivity of quantum-cascade lasers with subwavelength grating,” IEEE Photon. Technol. Lett.19(4), 221–223 (2007).
[CrossRef]

Sirtori, C.

J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, “Quantum Cascade Laser,” Science264(5158), 553–556 (1994).
[CrossRef] [PubMed]

Sivco, D. L.

A. O. Dirisu, G. Silva, Z. Liu, C. F. Gmachl, F. J. Towner, J. Bruno, and D. L. Sivco, “Reduction of facet reflectivity of quantum-cascade lasers with subwavelength grating,” IEEE Photon. Technol. Lett.19(4), 221–223 (2007).
[CrossRef]

M. Troccoli, C. Gmachl, F. Capasso, D. L. Sivco, and A. Y. Cho, “Mid-infrared (λ≈7.4 µm) quantum cascade laser amplifier for high power single-mode emission and improved beam quality,” Appl. Phys. Lett.80(22), 4103 (2002).
[CrossRef]

F. Capasso, R. Paiella, R. Martini, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, and E. A. Whittaker, “Quantum Cascade Lasers: Ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron.38(6), 511–532 (2002).
[CrossRef]

J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, “Quantum Cascade Laser,” Science264(5158), 553–556 (1994).
[CrossRef] [PubMed]

Slivken, S.

Y. Bai, S. Slivken, Q. Y. Lu, N. Bandyopadhyay, and M. Razeghi, “Angled cavity broad area quantum cascade lasers,” Appl. Phys. Lett.101(8), 081106 (2012).
[CrossRef]

Y. Bai, S. R. Darvish, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “Optimizing facet coating of quantum cascade lasers for low power consumption,” J. Appl. Phys.109(5), 053103 (2011).
[CrossRef]

Sommers, H. S.

M. Ettenberg, H. S. Sommers, H. Kressel, and H. F. Lockwood, “Control of facet damage in GaAs laser diodes,” Appl. Phys. Lett.18(12), 571 (1971).
[CrossRef]

Strasser, G.

B. Schwarz, P. Reininger, H. Detz, T. Zederbauer, A. M. Andrews, S. Kalchmair, W. Schrenk, O. Baumgartner, H. Kosina, and G. Strasser, “A bi-functional quantum cascade device for same frequency lasing and detection,” Appl. Phys. Lett.101(19), 191109 (2012).
[CrossRef]

E. Mujagić, M. Nobile, H. Detz, W. Schrenk, J. Chen, C. Gmachl, and G. Strasser, “Ring cavity induced threshold reduction in single-mode surface emitting quantum cascade lasers,” Appl. Phys. Lett.96(3), 031111 (2010).
[CrossRef]

Tanbun-Ek, T.

Z. Liu, D. Wasserman, S. S. Howard, A. J. Hoffman, C. F. Gmachl, X. Wang, T. Tanbun-Ek, L. Cheng, and F. S. Choa, “Room-temperature continuous-wave quantum cascade lasers grown by MOCVD without lateral regrowth,” IEEE Photon. Technol. Lett.18(12), 1347–1349 (2006).
[CrossRef]

Taubman, M. S.

F. Capasso, R. Paiella, R. Martini, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, and E. A. Whittaker, “Quantum Cascade Lasers: Ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron.38(6), 511–532 (2002).
[CrossRef]

Tittel, F. K.

G. Wysocki, R. Lewicki, R. F. Curl, F. K. Tittel, L. Diehl, F. Capasso, M. Troccoli, G. Hofler, D. Bour, S. Corzine, R. Maulini, M. Giovannini, and J. Faist, “Widely tunable mode-hop free external cavity quantum cascade lasers for high resolution spectroscopy and chemical sensing,” Appl. Phys. B92(3), 305–311 (2008).
[CrossRef]

Towner, F. J.

A. O. Dirisu, G. Silva, Z. Liu, C. F. Gmachl, F. J. Towner, J. Bruno, and D. L. Sivco, “Reduction of facet reflectivity of quantum-cascade lasers with subwavelength grating,” IEEE Photon. Technol. Lett.19(4), 221–223 (2007).
[CrossRef]

Troccoli, M.

G. Wysocki, R. Lewicki, R. F. Curl, F. K. Tittel, L. Diehl, F. Capasso, M. Troccoli, G. Hofler, D. Bour, S. Corzine, R. Maulini, M. Giovannini, and J. Faist, “Widely tunable mode-hop free external cavity quantum cascade lasers for high resolution spectroscopy and chemical sensing,” Appl. Phys. B92(3), 305–311 (2008).
[CrossRef]

M. Troccoli, C. Gmachl, F. Capasso, D. L. Sivco, and A. Y. Cho, “Mid-infrared (λ≈7.4 µm) quantum cascade laser amplifier for high power single-mode emission and improved beam quality,” Appl. Phys. Lett.80(22), 4103 (2002).
[CrossRef]

Tsekoun, A.

R. Maulini, A. Lyakh, A. Tsekoun, R. Go, C. Pflügl, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett.95(15), 151112 (2009).
[CrossRef]

Unterrainer, K.

F. Capasso, R. Paiella, R. Martini, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, and E. A. Whittaker, “Quantum Cascade Lasers: Ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron.38(6), 511–532 (2002).
[CrossRef]

Völzke, H.

M. Hannemann, A. Antufjew, K. Borgmann, F. Hempel, T. Ittermann, S. Welzel, K. D. Weltmann, H. Völzke, and J. Röpcke, “Influence of age and sex in exhaled breath samples investigated by means of infrared laser absorption spectroscopy,” J. Breath. Res.5(2), 027101 (2011).
[CrossRef] [PubMed]

Wang, X.

Z. Liu, D. Wasserman, S. S. Howard, A. J. Hoffman, C. F. Gmachl, X. Wang, T. Tanbun-Ek, L. Cheng, and F. S. Choa, “Room-temperature continuous-wave quantum cascade lasers grown by MOCVD without lateral regrowth,” IEEE Photon. Technol. Lett.18(12), 1347–1349 (2006).
[CrossRef]

Wasserman, D.

Z. Liu, D. Wasserman, S. S. Howard, A. J. Hoffman, C. F. Gmachl, X. Wang, T. Tanbun-Ek, L. Cheng, and F. S. Choa, “Room-temperature continuous-wave quantum cascade lasers grown by MOCVD without lateral regrowth,” IEEE Photon. Technol. Lett.18(12), 1347–1349 (2006).
[CrossRef]

Weltmann, K. D.

M. Hannemann, A. Antufjew, K. Borgmann, F. Hempel, T. Ittermann, S. Welzel, K. D. Weltmann, H. Völzke, and J. Röpcke, “Influence of age and sex in exhaled breath samples investigated by means of infrared laser absorption spectroscopy,” J. Breath. Res.5(2), 027101 (2011).
[CrossRef] [PubMed]

Welzel, S.

M. Hannemann, A. Antufjew, K. Borgmann, F. Hempel, T. Ittermann, S. Welzel, K. D. Weltmann, H. Völzke, and J. Röpcke, “Influence of age and sex in exhaled breath samples investigated by means of infrared laser absorption spectroscopy,” J. Breath. Res.5(2), 027101 (2011).
[CrossRef] [PubMed]

Whittaker, E. A.

F. Capasso, R. Paiella, R. Martini, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, and E. A. Whittaker, “Quantum Cascade Lasers: Ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron.38(6), 511–532 (2002).
[CrossRef]

Williams, R. M.

F. Capasso, R. Paiella, R. Martini, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, and E. A. Whittaker, “Quantum Cascade Lasers: Ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron.38(6), 511–532 (2002).
[CrossRef]

Wilson, L. R.

E. A. Zibik, W. H. Ng, D. G. Revin, L. R. Wilson, J. W. Cockburn, K. M. Groom, and M. Hopkinson, “Broadband 6 µm < λ < 8 µm superluminescent quantum cascade light-emitting diodes,” Appl. Phys. Lett.88(12), 121109 (2006).
[CrossRef]

Wysocki, G.

G. Wysocki, R. Lewicki, R. F. Curl, F. K. Tittel, L. Diehl, F. Capasso, M. Troccoli, G. Hofler, D. Bour, S. Corzine, R. Maulini, M. Giovannini, and J. Faist, “Widely tunable mode-hop free external cavity quantum cascade lasers for high resolution spectroscopy and chemical sensing,” Appl. Phys. B92(3), 305–311 (2008).
[CrossRef]

Yamanishi, M.

N. Yu, R. Blanchard, J. Fan, F. Capasso, T. Edamura, M. Yamanishi, and H. Kan, “Small divergence edge-emitting semiconductor lasers with two-dimensional plasmonic collimators,” Appl. Phys. Lett.93(18), 181101 (2008).
[CrossRef]

Yao, Y.

Y. Yao, A. J. Hoffman, and C. F. Gmachl, “Mid-infrared quantum cascade lasers,” Nat. Photonics6(7), 432–439 (2012).
[CrossRef]

Yu, N.

N. Yu, R. Blanchard, J. Fan, F. Capasso, T. Edamura, M. Yamanishi, and H. Kan, “Small divergence edge-emitting semiconductor lasers with two-dimensional plasmonic collimators,” Appl. Phys. Lett.93(18), 181101 (2008).
[CrossRef]

Zah, C. E.

C. E. Zah, J. S. Osinski, C. Caneau, S. G. Menocal, L. A. Reith, J. Salzman, F. K. Shokoohi, and T. P. Lee, “Fabrication and performance of 1.5µm GaInAsP travelling-wave laser amplifiers with angled facets,” Electron. Lett.23(19), 990 (1987).
[CrossRef]

Zederbauer, T.

B. Schwarz, P. Reininger, H. Detz, T. Zederbauer, A. M. Andrews, S. Kalchmair, W. Schrenk, O. Baumgartner, H. Kosina, and G. Strasser, “A bi-functional quantum cascade device for same frequency lasing and detection,” Appl. Phys. Lett.101(19), 191109 (2012).
[CrossRef]

Zhang, Z. Y.

Z. Y. Zhang, I. J. Luxmoore, C. Y. Jin, H. Y. Liu, Q. Jiang, K. M. Groom, D. T. Childs, M. Hopkinson, A. G. Cullis, and R. A. Hogg, “Effect of facet angle on effective facet reflectivity and operating characteristics of quantum dot edge emitting lasers and superluminescent light-emitting diodes,” Appl. Phys. Lett.91(8), 081112 (2007).
[CrossRef]

Zibik, E. A.

E. A. Zibik, W. H. Ng, D. G. Revin, L. R. Wilson, J. W. Cockburn, K. M. Groom, and M. Hopkinson, “Broadband 6 µm < λ < 8 µm superluminescent quantum cascade light-emitting diodes,” Appl. Phys. Lett.88(12), 121109 (2006).
[CrossRef]

Appl. Phys. B

G. Wysocki, R. Lewicki, R. F. Curl, F. K. Tittel, L. Diehl, F. Capasso, M. Troccoli, G. Hofler, D. Bour, S. Corzine, R. Maulini, M. Giovannini, and J. Faist, “Widely tunable mode-hop free external cavity quantum cascade lasers for high resolution spectroscopy and chemical sensing,” Appl. Phys. B92(3), 305–311 (2008).
[CrossRef]

Appl. Phys. Lett.

B. Schwarz, P. Reininger, H. Detz, T. Zederbauer, A. M. Andrews, S. Kalchmair, W. Schrenk, O. Baumgartner, H. Kosina, and G. Strasser, “A bi-functional quantum cascade device for same frequency lasing and detection,” Appl. Phys. Lett.101(19), 191109 (2012).
[CrossRef]

R. Maulini, A. Lyakh, A. Tsekoun, R. Go, C. Pflügl, L. Diehl, F. Capasso, C. Kumar, and N. Patel, “High power thermoelectrically cooled and uncooled quantum cascade lasers with optimized reflectivity facet coatings,” Appl. Phys. Lett.95(15), 151112 (2009).
[CrossRef]

M. Troccoli, C. Gmachl, F. Capasso, D. L. Sivco, and A. Y. Cho, “Mid-infrared (λ≈7.4 µm) quantum cascade laser amplifier for high power single-mode emission and improved beam quality,” Appl. Phys. Lett.80(22), 4103 (2002).
[CrossRef]

E. A. Zibik, W. H. Ng, D. G. Revin, L. R. Wilson, J. W. Cockburn, K. M. Groom, and M. Hopkinson, “Broadband 6 µm < λ < 8 µm superluminescent quantum cascade light-emitting diodes,” Appl. Phys. Lett.88(12), 121109 (2006).
[CrossRef]

Y. Bai, S. Slivken, Q. Y. Lu, N. Bandyopadhyay, and M. Razeghi, “Angled cavity broad area quantum cascade lasers,” Appl. Phys. Lett.101(8), 081106 (2012).
[CrossRef]

N. Yu, R. Blanchard, J. Fan, F. Capasso, T. Edamura, M. Yamanishi, and H. Kan, “Small divergence edge-emitting semiconductor lasers with two-dimensional plasmonic collimators,” Appl. Phys. Lett.93(18), 181101 (2008).
[CrossRef]

M. Ettenberg, H. S. Sommers, H. Kressel, and H. F. Lockwood, “Control of facet damage in GaAs laser diodes,” Appl. Phys. Lett.18(12), 571 (1971).
[CrossRef]

E. Mujagić, M. Nobile, H. Detz, W. Schrenk, J. Chen, C. Gmachl, and G. Strasser, “Ring cavity induced threshold reduction in single-mode surface emitting quantum cascade lasers,” Appl. Phys. Lett.96(3), 031111 (2010).
[CrossRef]

Z. Y. Zhang, I. J. Luxmoore, C. Y. Jin, H. Y. Liu, Q. Jiang, K. M. Groom, D. T. Childs, M. Hopkinson, A. G. Cullis, and R. A. Hogg, “Effect of facet angle on effective facet reflectivity and operating characteristics of quantum dot edge emitting lasers and superluminescent light-emitting diodes,” Appl. Phys. Lett.91(8), 081112 (2007).
[CrossRef]

Electron. Lett.

C. E. Zah, J. S. Osinski, C. Caneau, S. G. Menocal, L. A. Reith, J. Salzman, F. K. Shokoohi, and T. P. Lee, “Fabrication and performance of 1.5µm GaInAsP travelling-wave laser amplifiers with angled facets,” Electron. Lett.23(19), 990 (1987).
[CrossRef]

C. F. Lin, “Superluminescent diodes with angled facet etched by chemically assisted ion beam etching,” Electron. Lett.27(11), 968 (1991).
[CrossRef]

IEEE J. Quantum Electron.

F. Capasso, R. Paiella, R. Martini, R. Colombelli, C. Gmachl, T. L. Myers, M. S. Taubman, R. M. Williams, C. G. Bethea, K. Unterrainer, H. Y. Hwang, D. L. Sivco, A. Y. Cho, A. M. Sergent, H. C. Liu, and E. A. Whittaker, “Quantum Cascade Lasers: Ultrahigh-speed operation, optical wireless communication, narrow linewidth, and far-infrared emission,” IEEE J. Quantum Electron.38(6), 511–532 (2002).
[CrossRef]

S. Kumar, “Recent progress in Terahertz Quantum Cascade Lasers,” IEEE J. Quantum Electron.17(1), 38–47 (2011).
[CrossRef]

IEEE Photon. Technol. Lett.

A. O. Dirisu, G. Silva, Z. Liu, C. F. Gmachl, F. J. Towner, J. Bruno, and D. L. Sivco, “Reduction of facet reflectivity of quantum-cascade lasers with subwavelength grating,” IEEE Photon. Technol. Lett.19(4), 221–223 (2007).
[CrossRef]

Z. Liu, D. Wasserman, S. S. Howard, A. J. Hoffman, C. F. Gmachl, X. Wang, T. Tanbun-Ek, L. Cheng, and F. S. Choa, “Room-temperature continuous-wave quantum cascade lasers grown by MOCVD without lateral regrowth,” IEEE Photon. Technol. Lett.18(12), 1347–1349 (2006).
[CrossRef]

J. Appl. Phys.

Y. Bai, S. R. Darvish, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “Optimizing facet coating of quantum cascade lasers for low power consumption,” J. Appl. Phys.109(5), 053103 (2011).
[CrossRef]

J. Breath. Res.

M. Hannemann, A. Antufjew, K. Borgmann, F. Hempel, T. Ittermann, S. Welzel, K. D. Weltmann, H. Völzke, and J. Röpcke, “Influence of age and sex in exhaled breath samples investigated by means of infrared laser absorption spectroscopy,” J. Breath. Res.5(2), 027101 (2011).
[CrossRef] [PubMed]

Nat. Photonics

Y. Yao, A. J. Hoffman, and C. F. Gmachl, “Mid-infrared quantum cascade lasers,” Nat. Photonics6(7), 432–439 (2012).
[CrossRef]

Science

J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, “Quantum Cascade Laser,” Science264(5158), 553–556 (1994).
[CrossRef] [PubMed]

Other

K. Petermann, Laser diode modulation and noise, (KTH Scientific Publishers, Dordrecht, 1991), Chap. 2.4. “Lasing characteristic of Fabry-Pérot Type Laser”.

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (7)

Fig. 1
Fig. 1

Sketch of the (a) symmetric and (b) asymmetric light intensity distribution inside a laser cavity. The arrows (dash) and arrows (line) are indicating the light reflection and transmission at the laser facet.

Fig. 2
Fig. 2

Sketch of the asymmetric light intensity distribution inside a laser cavity for the tilted front facet. The arrows (dash), arrows (line) and symbols ( × —–) are indicating the light reflection, emission at the laser facets and reflected light at the tilted front facet which is not coupled back into the cavity, respectively.

Fig. 3
Fig. 3

(a) Sketch of a QCL with a tilted front facet. Only the front facet of the QCLs was milled, while the back facet was left as cleaved. (b) A scanning electron microscope picture shows the fabricated tilted front facet (θF = 12°). ( + ) and (–) signs are defined for the far field measurement in the following section.

Fig. 4
Fig. 4

(a) The ratio of the threshold current densities of QCLs after FIB milling to before FIB milling for all given facet angles. (b) The experimentally determined modal reflectivity (triangles) of the tilted facet as a function of the facet angles.

Fig. 5
Fig. 5

(a) A comparison of LIV characteristics (the linear part of the LI curve just above threshold) for the emission from front and back facets of the QCL with a facet angle of 17°. (b) Ratios of the slope efficiencies between front and back facet (triangles), as a function of facet angles compared to the ratios (Eq. (2) of the power arriving at the laser facets (stars).

Fig. 6
Fig. 6

(a) A comparison of LJV characteristics between before and after FIB milling for QCLs with a facet angle of 8°. (b) The ratios, between before and after FIB milling, of ηs for the QCLs as a function of the facet angles, based on the emitted light from the front facet.

Fig. 7
Fig. 7

(a) Far field profiles measured along the lateral (Y) direction [see Fig. 3(a)] of various facet angles of QCLs, driven nearly at the peak optical power. The dash line at 0° represents the ridge normal direction. (b) The beam emission angle from the ridge normal (circles) and FWHM (squares) as a function of the facet angles are shown.

Metrics