Abstract

We report gain-guided broad area quantum cascade lasers at 4.55 μm. The devices were processed in a buried heterostructure configuration with a current injector section much narrower than the active region. They demonstrate 23.5 W peak power at a temperature of 20°C and duty cycle of 1%, while their far field consists of a single symmetric lobe centered on the optical axis. These experimental results are supported well by 2D numerical simulations of electric currents and optical fields in a device cross-section.

© 2016 Optical Society of America

Full Article  |  PDF Article
OSA Recommended Articles
Recent advances in mid infrared (3-5µm) Quantum Cascade Lasers

Manijeh Razeghi, Neelanjan Bandyopadhyay, Yanbo Bai, Quanyong Lu, and Steven Slivken
Opt. Mater. Express 3(11) 1872-1884 (2013)

Recent progress of quantum cascade laser research from 3 to 12  μm at the Center for Quantum Devices [Invited]

Manijeh Razeghi, Wenjia Zhou, Steven Slivken, Quan-Yong Lu, Donghai Wu, and Ryan McClintock
Appl. Opt. 56(31) H30-H44 (2017)

λ~7.1 μm quantum cascade lasers with 19% wall-plug efficiency at room temperature

Richard Maulini, Arkadiy Lyakh, Alexei Tsekoun, and C. Kumar N. Patel
Opt. Express 19(18) 17203-17211 (2011)

More Recommended Articles

References

  • View by:
  • Article Order
  • |
  • Year
  • |
  • Author
  • |
  • Publication
  1. A. Lyakh, R. Maulini, A. Tsekoun, R. Go, and C. K. N. Patel, “Tapered 4.7 μm quantum cascade lasers with highly strained active region composition delivering over 4.5 watts of continuous wave optical power,” Opt. Express 20, 4382–4388 (2012).
    [Crossref] [PubMed]
  2. Y. Bai, N. Bandyopadhyay, S. Tsao, S. Slivken, and M. Razeghi, “Room temperature quantum cascade lasers with 27% wall plug efficiency,” Appl. Phys. Lett. 98, 181102 (2011).
    [Crossref]
  3. R. Maulini, A. Lyakh, A. Tsekoun, and C. K. N. Patel, “λ ~7.1 μ m quantum cascade lasers with 19% wall-plug efficiency at room temperature,” Opt. Express 19, 17203–17211 (2011).
    [Crossref] [PubMed]
  4. Y. Bai, S. Slivken, S. R. Darvish, A. Haddadi, B. Gökden, and M. Razeghi, “High power broad area quantum cascade lasers,” Appl. Phys. Lett. 95, 221104 (2009).
    [Crossref]
  5. B. Gökden, Y. Bai, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “Broad area photonic crystal distributed feedback quantum cascade lasers emitting 34 W at λ ~ 4.36 μ m,” Appl. Phys. Lett. 97, 131112 (2010).
    [Crossref]
  6. D. Heydari, Y. Bai, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “High brightness angled cavity quantum cascade lasers,” Appl. Phys. Lett. 106, 091105 (2015).
    [Crossref]
  7. J. D. Kirch, C.-C. Chang, C. Boyle, L. J. Mawst, D. Lindberg, T. Earles, and D. Botez, “5.5 W near-diffraction-limited power from resonant leaky-wave coupled phase-locked arrays of quantum cascade lasers,” Appl. Phys. Lett. 106, 061113 (2015).
    [Crossref]
  8. F. Salin and J. Squier, “Gain guiding in solid-state lasers,” Opt. Lett. 17, 1352–1354 (1992).
    [Crossref] [PubMed]
  9. M. N. Polyanskiy, “Refractive index database,” http://refractiveindex.info (2016).
  10. V. Siklitsky, “Electronic archive: New semiconductor materials. characteristics and properties,” http://www.ioffe.ru/SVA/NSM/ (2001).
  11. A. Lyakh, P. Zory, D. Wasserman, G. Shu, C. Gmachl, M. D’Souza, D. Botez, and D. Bour, “Narrow stripe-width, low-ridge high power quantum cascade lasers,” Appl. Phys. Lett. 90, 141107 (2007).
    [Crossref]
  12. R. Terazzi and J. Faist, “A density matrix model of transport and radiation in quantum cascade lasers,” New J. Phys. 12, 033045 (2010).
    [Crossref]
  13. K. Krishnaswami, B. E. Bernacki, B. D. Cannon, N. Ho, and N. C. Anheier, “Emission and Propagation Properties of Midinfrared Quantum Cascade Lasers,” IEEE Photon. Tech. Lett. 20, 306–308 (2008).
    [Crossref]
  14. A. Bismuto, S. Blaser, R. Terazzi, T. Gresch, and A. Muller, “High performance, low dissipation quantum cascade lasers across the mid-IR range,” Opt. Express 23, 5477 (2015).
    [Crossref] [PubMed]

2015 (3)

D. Heydari, Y. Bai, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “High brightness angled cavity quantum cascade lasers,” Appl. Phys. Lett. 106, 091105 (2015).
[Crossref]

J. D. Kirch, C.-C. Chang, C. Boyle, L. J. Mawst, D. Lindberg, T. Earles, and D. Botez, “5.5 W near-diffraction-limited power from resonant leaky-wave coupled phase-locked arrays of quantum cascade lasers,” Appl. Phys. Lett. 106, 061113 (2015).
[Crossref]

A. Bismuto, S. Blaser, R. Terazzi, T. Gresch, and A. Muller, “High performance, low dissipation quantum cascade lasers across the mid-IR range,” Opt. Express 23, 5477 (2015).
[Crossref] [PubMed]

2012 (1)

2011 (2)

Y. Bai, N. Bandyopadhyay, S. Tsao, S. Slivken, and M. Razeghi, “Room temperature quantum cascade lasers with 27% wall plug efficiency,” Appl. Phys. Lett. 98, 181102 (2011).
[Crossref]

R. Maulini, A. Lyakh, A. Tsekoun, and C. K. N. Patel, “λ ~7.1 μ m quantum cascade lasers with 19% wall-plug efficiency at room temperature,” Opt. Express 19, 17203–17211 (2011).
[Crossref] [PubMed]

2010 (2)

B. Gökden, Y. Bai, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “Broad area photonic crystal distributed feedback quantum cascade lasers emitting 34 W at λ ~ 4.36 μ m,” Appl. Phys. Lett. 97, 131112 (2010).
[Crossref]

R. Terazzi and J. Faist, “A density matrix model of transport and radiation in quantum cascade lasers,” New J. Phys. 12, 033045 (2010).
[Crossref]

2009 (1)

Y. Bai, S. Slivken, S. R. Darvish, A. Haddadi, B. Gökden, and M. Razeghi, “High power broad area quantum cascade lasers,” Appl. Phys. Lett. 95, 221104 (2009).
[Crossref]

2008 (1)

K. Krishnaswami, B. E. Bernacki, B. D. Cannon, N. Ho, and N. C. Anheier, “Emission and Propagation Properties of Midinfrared Quantum Cascade Lasers,” IEEE Photon. Tech. Lett. 20, 306–308 (2008).
[Crossref]

2007 (1)

A. Lyakh, P. Zory, D. Wasserman, G. Shu, C. Gmachl, M. D’Souza, D. Botez, and D. Bour, “Narrow stripe-width, low-ridge high power quantum cascade lasers,” Appl. Phys. Lett. 90, 141107 (2007).
[Crossref]

1992 (1)

Anheier, N. C.

K. Krishnaswami, B. E. Bernacki, B. D. Cannon, N. Ho, and N. C. Anheier, “Emission and Propagation Properties of Midinfrared Quantum Cascade Lasers,” IEEE Photon. Tech. Lett. 20, 306–308 (2008).
[Crossref]

Bai, Y.

D. Heydari, Y. Bai, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “High brightness angled cavity quantum cascade lasers,” Appl. Phys. Lett. 106, 091105 (2015).
[Crossref]

Y. Bai, N. Bandyopadhyay, S. Tsao, S. Slivken, and M. Razeghi, “Room temperature quantum cascade lasers with 27% wall plug efficiency,” Appl. Phys. Lett. 98, 181102 (2011).
[Crossref]

B. Gökden, Y. Bai, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “Broad area photonic crystal distributed feedback quantum cascade lasers emitting 34 W at λ ~ 4.36 μ m,” Appl. Phys. Lett. 97, 131112 (2010).
[Crossref]

Y. Bai, S. Slivken, S. R. Darvish, A. Haddadi, B. Gökden, and M. Razeghi, “High power broad area quantum cascade lasers,” Appl. Phys. Lett. 95, 221104 (2009).
[Crossref]

Bandyopadhyay, N.

D. Heydari, Y. Bai, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “High brightness angled cavity quantum cascade lasers,” Appl. Phys. Lett. 106, 091105 (2015).
[Crossref]

Y. Bai, N. Bandyopadhyay, S. Tsao, S. Slivken, and M. Razeghi, “Room temperature quantum cascade lasers with 27% wall plug efficiency,” Appl. Phys. Lett. 98, 181102 (2011).
[Crossref]

B. Gökden, Y. Bai, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “Broad area photonic crystal distributed feedback quantum cascade lasers emitting 34 W at λ ~ 4.36 μ m,” Appl. Phys. Lett. 97, 131112 (2010).
[Crossref]

Bernacki, B. E.

K. Krishnaswami, B. E. Bernacki, B. D. Cannon, N. Ho, and N. C. Anheier, “Emission and Propagation Properties of Midinfrared Quantum Cascade Lasers,” IEEE Photon. Tech. Lett. 20, 306–308 (2008).
[Crossref]

Bismuto, A.

Blaser, S.

Botez, D.

J. D. Kirch, C.-C. Chang, C. Boyle, L. J. Mawst, D. Lindberg, T. Earles, and D. Botez, “5.5 W near-diffraction-limited power from resonant leaky-wave coupled phase-locked arrays of quantum cascade lasers,” Appl. Phys. Lett. 106, 061113 (2015).
[Crossref]

A. Lyakh, P. Zory, D. Wasserman, G. Shu, C. Gmachl, M. D’Souza, D. Botez, and D. Bour, “Narrow stripe-width, low-ridge high power quantum cascade lasers,” Appl. Phys. Lett. 90, 141107 (2007).
[Crossref]

Bour, D.

A. Lyakh, P. Zory, D. Wasserman, G. Shu, C. Gmachl, M. D’Souza, D. Botez, and D. Bour, “Narrow stripe-width, low-ridge high power quantum cascade lasers,” Appl. Phys. Lett. 90, 141107 (2007).
[Crossref]

Boyle, C.

J. D. Kirch, C.-C. Chang, C. Boyle, L. J. Mawst, D. Lindberg, T. Earles, and D. Botez, “5.5 W near-diffraction-limited power from resonant leaky-wave coupled phase-locked arrays of quantum cascade lasers,” Appl. Phys. Lett. 106, 061113 (2015).
[Crossref]

Cannon, B. D.

K. Krishnaswami, B. E. Bernacki, B. D. Cannon, N. Ho, and N. C. Anheier, “Emission and Propagation Properties of Midinfrared Quantum Cascade Lasers,” IEEE Photon. Tech. Lett. 20, 306–308 (2008).
[Crossref]

Chang, C.-C.

J. D. Kirch, C.-C. Chang, C. Boyle, L. J. Mawst, D. Lindberg, T. Earles, and D. Botez, “5.5 W near-diffraction-limited power from resonant leaky-wave coupled phase-locked arrays of quantum cascade lasers,” Appl. Phys. Lett. 106, 061113 (2015).
[Crossref]

D’Souza, M.

A. Lyakh, P. Zory, D. Wasserman, G. Shu, C. Gmachl, M. D’Souza, D. Botez, and D. Bour, “Narrow stripe-width, low-ridge high power quantum cascade lasers,” Appl. Phys. Lett. 90, 141107 (2007).
[Crossref]

Darvish, S. R.

Y. Bai, S. Slivken, S. R. Darvish, A. Haddadi, B. Gökden, and M. Razeghi, “High power broad area quantum cascade lasers,” Appl. Phys. Lett. 95, 221104 (2009).
[Crossref]

Earles, T.

J. D. Kirch, C.-C. Chang, C. Boyle, L. J. Mawst, D. Lindberg, T. Earles, and D. Botez, “5.5 W near-diffraction-limited power from resonant leaky-wave coupled phase-locked arrays of quantum cascade lasers,” Appl. Phys. Lett. 106, 061113 (2015).
[Crossref]

Faist, J.

R. Terazzi and J. Faist, “A density matrix model of transport and radiation in quantum cascade lasers,” New J. Phys. 12, 033045 (2010).
[Crossref]

Gmachl, C.

A. Lyakh, P. Zory, D. Wasserman, G. Shu, C. Gmachl, M. D’Souza, D. Botez, and D. Bour, “Narrow stripe-width, low-ridge high power quantum cascade lasers,” Appl. Phys. Lett. 90, 141107 (2007).
[Crossref]

Go, R.

Gökden, B.

B. Gökden, Y. Bai, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “Broad area photonic crystal distributed feedback quantum cascade lasers emitting 34 W at λ ~ 4.36 μ m,” Appl. Phys. Lett. 97, 131112 (2010).
[Crossref]

Y. Bai, S. Slivken, S. R. Darvish, A. Haddadi, B. Gökden, and M. Razeghi, “High power broad area quantum cascade lasers,” Appl. Phys. Lett. 95, 221104 (2009).
[Crossref]

Gresch, T.

Haddadi, A.

Y. Bai, S. Slivken, S. R. Darvish, A. Haddadi, B. Gökden, and M. Razeghi, “High power broad area quantum cascade lasers,” Appl. Phys. Lett. 95, 221104 (2009).
[Crossref]

Heydari, D.

D. Heydari, Y. Bai, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “High brightness angled cavity quantum cascade lasers,” Appl. Phys. Lett. 106, 091105 (2015).
[Crossref]

Ho, N.

K. Krishnaswami, B. E. Bernacki, B. D. Cannon, N. Ho, and N. C. Anheier, “Emission and Propagation Properties of Midinfrared Quantum Cascade Lasers,” IEEE Photon. Tech. Lett. 20, 306–308 (2008).
[Crossref]

Kirch, J. D.

J. D. Kirch, C.-C. Chang, C. Boyle, L. J. Mawst, D. Lindberg, T. Earles, and D. Botez, “5.5 W near-diffraction-limited power from resonant leaky-wave coupled phase-locked arrays of quantum cascade lasers,” Appl. Phys. Lett. 106, 061113 (2015).
[Crossref]

Krishnaswami, K.

K. Krishnaswami, B. E. Bernacki, B. D. Cannon, N. Ho, and N. C. Anheier, “Emission and Propagation Properties of Midinfrared Quantum Cascade Lasers,” IEEE Photon. Tech. Lett. 20, 306–308 (2008).
[Crossref]

Lindberg, D.

J. D. Kirch, C.-C. Chang, C. Boyle, L. J. Mawst, D. Lindberg, T. Earles, and D. Botez, “5.5 W near-diffraction-limited power from resonant leaky-wave coupled phase-locked arrays of quantum cascade lasers,” Appl. Phys. Lett. 106, 061113 (2015).
[Crossref]

Lyakh, A.

Maulini, R.

Mawst, L. J.

J. D. Kirch, C.-C. Chang, C. Boyle, L. J. Mawst, D. Lindberg, T. Earles, and D. Botez, “5.5 W near-diffraction-limited power from resonant leaky-wave coupled phase-locked arrays of quantum cascade lasers,” Appl. Phys. Lett. 106, 061113 (2015).
[Crossref]

Muller, A.

Patel, C. K. N.

Razeghi, M.

D. Heydari, Y. Bai, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “High brightness angled cavity quantum cascade lasers,” Appl. Phys. Lett. 106, 091105 (2015).
[Crossref]

Y. Bai, N. Bandyopadhyay, S. Tsao, S. Slivken, and M. Razeghi, “Room temperature quantum cascade lasers with 27% wall plug efficiency,” Appl. Phys. Lett. 98, 181102 (2011).
[Crossref]

B. Gökden, Y. Bai, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “Broad area photonic crystal distributed feedback quantum cascade lasers emitting 34 W at λ ~ 4.36 μ m,” Appl. Phys. Lett. 97, 131112 (2010).
[Crossref]

Y. Bai, S. Slivken, S. R. Darvish, A. Haddadi, B. Gökden, and M. Razeghi, “High power broad area quantum cascade lasers,” Appl. Phys. Lett. 95, 221104 (2009).
[Crossref]

Salin, F.

Shu, G.

A. Lyakh, P. Zory, D. Wasserman, G. Shu, C. Gmachl, M. D’Souza, D. Botez, and D. Bour, “Narrow stripe-width, low-ridge high power quantum cascade lasers,” Appl. Phys. Lett. 90, 141107 (2007).
[Crossref]

Slivken, S.

D. Heydari, Y. Bai, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “High brightness angled cavity quantum cascade lasers,” Appl. Phys. Lett. 106, 091105 (2015).
[Crossref]

Y. Bai, N. Bandyopadhyay, S. Tsao, S. Slivken, and M. Razeghi, “Room temperature quantum cascade lasers with 27% wall plug efficiency,” Appl. Phys. Lett. 98, 181102 (2011).
[Crossref]

B. Gökden, Y. Bai, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “Broad area photonic crystal distributed feedback quantum cascade lasers emitting 34 W at λ ~ 4.36 μ m,” Appl. Phys. Lett. 97, 131112 (2010).
[Crossref]

Y. Bai, S. Slivken, S. R. Darvish, A. Haddadi, B. Gökden, and M. Razeghi, “High power broad area quantum cascade lasers,” Appl. Phys. Lett. 95, 221104 (2009).
[Crossref]

Squier, J.

Terazzi, R.

A. Bismuto, S. Blaser, R. Terazzi, T. Gresch, and A. Muller, “High performance, low dissipation quantum cascade lasers across the mid-IR range,” Opt. Express 23, 5477 (2015).
[Crossref] [PubMed]

R. Terazzi and J. Faist, “A density matrix model of transport and radiation in quantum cascade lasers,” New J. Phys. 12, 033045 (2010).
[Crossref]

Tsao, S.

Y. Bai, N. Bandyopadhyay, S. Tsao, S. Slivken, and M. Razeghi, “Room temperature quantum cascade lasers with 27% wall plug efficiency,” Appl. Phys. Lett. 98, 181102 (2011).
[Crossref]

Tsekoun, A.

Wasserman, D.

A. Lyakh, P. Zory, D. Wasserman, G. Shu, C. Gmachl, M. D’Souza, D. Botez, and D. Bour, “Narrow stripe-width, low-ridge high power quantum cascade lasers,” Appl. Phys. Lett. 90, 141107 (2007).
[Crossref]

Zory, P.

A. Lyakh, P. Zory, D. Wasserman, G. Shu, C. Gmachl, M. D’Souza, D. Botez, and D. Bour, “Narrow stripe-width, low-ridge high power quantum cascade lasers,” Appl. Phys. Lett. 90, 141107 (2007).
[Crossref]

Appl. Phys. Lett. (6)

Y. Bai, S. Slivken, S. R. Darvish, A. Haddadi, B. Gökden, and M. Razeghi, “High power broad area quantum cascade lasers,” Appl. Phys. Lett. 95, 221104 (2009).
[Crossref]

B. Gökden, Y. Bai, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “Broad area photonic crystal distributed feedback quantum cascade lasers emitting 34 W at λ ~ 4.36 μ m,” Appl. Phys. Lett. 97, 131112 (2010).
[Crossref]

D. Heydari, Y. Bai, N. Bandyopadhyay, S. Slivken, and M. Razeghi, “High brightness angled cavity quantum cascade lasers,” Appl. Phys. Lett. 106, 091105 (2015).
[Crossref]

J. D. Kirch, C.-C. Chang, C. Boyle, L. J. Mawst, D. Lindberg, T. Earles, and D. Botez, “5.5 W near-diffraction-limited power from resonant leaky-wave coupled phase-locked arrays of quantum cascade lasers,” Appl. Phys. Lett. 106, 061113 (2015).
[Crossref]

Y. Bai, N. Bandyopadhyay, S. Tsao, S. Slivken, and M. Razeghi, “Room temperature quantum cascade lasers with 27% wall plug efficiency,” Appl. Phys. Lett. 98, 181102 (2011).
[Crossref]

A. Lyakh, P. Zory, D. Wasserman, G. Shu, C. Gmachl, M. D’Souza, D. Botez, and D. Bour, “Narrow stripe-width, low-ridge high power quantum cascade lasers,” Appl. Phys. Lett. 90, 141107 (2007).
[Crossref]

IEEE Photon. Tech. Lett. (1)

K. Krishnaswami, B. E. Bernacki, B. D. Cannon, N. Ho, and N. C. Anheier, “Emission and Propagation Properties of Midinfrared Quantum Cascade Lasers,” IEEE Photon. Tech. Lett. 20, 306–308 (2008).
[Crossref]

New J. Phys. (1)

R. Terazzi and J. Faist, “A density matrix model of transport and radiation in quantum cascade lasers,” New J. Phys. 12, 033045 (2010).
[Crossref]

Opt. Express (3)

Opt. Lett. (1)

Other (2)

M. N. Polyanskiy, “Refractive index database,” http://refractiveindex.info (2016).

V. Siklitsky, “Electronic archive: New semiconductor materials. characteristics and properties,” http://www.ioffe.ru/SVA/NSM/ (2001).

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 (9)

Fig. 1
Fig. 1 Simulated TM00 optical mode intensity (color, a.u.) and current flow (red arrows) in the center of a cross-section of a gain-guided laser (one transverse symmetric half is shown). Applied voltage is 20 V.

Download Full Size | PPT Slide | PDF

Fig. 2
Fig. 2 Simulated current density lateral distribution in the active region of a gain-guided QCL as function of applied voltage (one transverse symmetric half is shown). Inset: half width at half maximum (HWHM) of current density distribution as function of applied voltage (solid curve) for 1 μm of cladding thickness left unetched as in fabricated devices. Simulations for 2 μm (dashed) and 3 μm (dotted) provided for comparison as well.

Download Full Size | PPT Slide | PDF

Fig. 3
Fig. 3 LIV (light-current-voltage) curves for index guided laser (left) and gain guided (right) at 20°C, 300 ns pulse width, 1% duty cycle. Bold lines - measured power, thinner lines - measured voltage, dashed - simulated voltage.

Download Full Size | PPT Slide | PDF

Fig. 4
Fig. 4 Simulated modal gain as function of applied voltage in a gain-guided QCL. High gain margin between the TM00 and TM01 modes makes first one always reach lasing threshold first.

Download Full Size | PPT Slide | PDF

Fig. 5
Fig. 5 Top: pulsed driver simplified schematics. Vin - input voltage, 1 - laser voltage control, 2 - pulse generation, 3 - amplified pulses for driving MOSFET gate, 4 - laser voltage measurement, 5 - laser current measurement, 6 - external communication and synchronization, RS - sense resistor, AMP - operational amplifier. Solid line indicates the main current path, dashed ones - supplementary signals. Bottom: board photo, size: 88 × 33 mm.

Download Full Size | PPT Slide | PDF

Fig. 6
Fig. 6 Typical measured emission spectrum of the fabricated lasers.

Download Full Size | PPT Slide | PDF

Fig. 7
Fig. 7 Measured beam intensity profiles of a gain-guided QCL at a distance of 6 mm for various injection currents. Each image dimensions are 3.0 × 12.4 mm (initially 12.4 × 12.4, sides containing no signal were cropped). Ith ≈ 6 A.

Download Full Size | PPT Slide | PDF

Fig. 8
Fig. 8 Measured horizontal far field intensity of a gain-guided QCL at various currents (dots) along with gaussian fits (lines). Curves are shifted vertically with a step of 0.1 for distinctness. Inset: half angle beam divergence (θd) at 1/e2 of maximum value extracted from gaussian fits with black error bars representing standard deviation errors.

Download Full Size | PPT Slide | PDF

Fig. 9
Fig. 9 Top left: measured instantaneous horizontal far field intensity evolution (color, a.u.) of a gain-guided QCL during 300 ns pulse at maximum current of 20 A showing transition from TM00 to high order modes. Top right: same data averaged from 0 ns to a given time (50 ns, 100 ns, …) shown with black dots along with gaussian fits (red lines). Bottom: half angle beam divergence (θd) at 1/e2 of maximum value extracted from gaussian fits with black error bars representing standard deviation errors.

Download Full Size | PPT Slide | PDF

Metrics