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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 20, Iss. 4 — Feb. 13, 2012
  • pp: 3866–3876

Terahertz quantum cascade lasers operating up to ∼ 200 K with optimized oscillator strength and improved injection tunneling

S. Fathololoumi, E. Dupont, C.W.I. Chan, Z.R. Wasilewski, S.R. Laframboise, D. Ban, A. Mátyás, C. Jirauschek, Q. Hu, and H. C. Liu  »View Author Affiliations


Optics Express, Vol. 20, Issue 4, pp. 3866-3876 (2012)
http://dx.doi.org/10.1364/OE.20.003866


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Abstract

A new temperature performance record of 199.5 K for terahertz quantum cascade lasers is achieved by optimizing the lasing transition oscillator strength of the resonant phonon based three-well design. The optimum oscillator strength of 0.58 was found to be larger than that of the previous record (0.41) by Kumar et al. [Appl. Phys. Lett. 94, 131105 (2009)]. The choice of tunneling barrier thicknesses was determined with a simplified density matrix model, which converged towards higher tunneling coupling strengths than previously explored and nearly perfect alignment of the states across the injection and extraction barriers at the design electric field. At 8 K, the device showed a threshold current density of 1 kA/cm2, with a peak output power of ∼ 38 mW, and lasing frequency blue-shifting from 2.6 THz to 2.85 THz with increasing bias. The wavelength blue-shifted to 3.22 THz closer to the maximum operating temperature of 199.5 K, which corresponds to ∼ 1.28ħω/κB. The voltage dependence of laser frequency is related to the Stark effect of two intersubband transitions and is compared with the simulated gain spectra obtained by a Monte Carlo approach.

© 2012 OSA

OCIS Codes
(140.5965) Lasers and laser optics : Semiconductor lasers, quantum cascade

ToC Category:
Lasers and Laser Optics

History
Original Manuscript: November 21, 2011
Revised Manuscript: January 17, 2012
Manuscript Accepted: January 18, 2012
Published: February 1, 2012

Citation
S. Fathololoumi, E. Dupont, C.W.I. Chan, Z.R. Wasilewski, S.R. Laframboise, D. Ban, A. Mátyás, C. Jirauschek, Q. Hu, and H. C. Liu, "Terahertz quantum cascade lasers operating up to ∼ 200 K with optimized oscillator strength and improved injection tunneling," Opt. Express 20, 3866-3876 (2012)
http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-20-4-3866


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References

  1. R. Kohler, A. Tredicucci, F. Beltram, H. E. Beere, E. H. Linfield, A. G. Davies, D. Ritchie, R. C. Iotti, and F. Rossi, “Terahertz semiconductor-heterostructure laser,” Nature417, 156–159 (2002). [CrossRef] [PubMed]
  2. B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, “Operation of terahertz quantum-cascade lasers at 164 K in pulsed mode and at 117 K in continuous-wave mode,” Opt. Express13, 3331–3339 (2005). [CrossRef] [PubMed]
  3. H. Luo, S. R. Laframboise, Z. R. Wasilewski, and H. C. Liu, “Terahertz quantum cascade lasers based on a three-well active module,” Appl. Phys. Lett.90, 041112 (2007). [CrossRef]
  4. M. A. Belkin, J. A. Fan, S. Hormoz, F. Capasso, S. P. Khanna, M. Lachab, A. G. Davies, and E. H. Linfield, “Terahertz quantum cascade lasers with copper metal-metal waveguides operating up to 178 K,” Opt. Express16, 3242–3248 (2008). [CrossRef] [PubMed]
  5. S. Kumar, Q. Hu, and J. L. Reno, “186 K operation of terahertz quantum cascade lasers based on a diagonal design,” Appl. Phys. Lett.94, 131105 (2009). [CrossRef]
  6. S. Kumar, C. W. I. Chan, Q. Hu, and J. L. Reno, “A 1.8-THz quantum cascade laser operating significantly above the temperature of ħω/κB,” Nat. Phys.7, 166–171 (2011). [CrossRef]
  7. R. W. Adams, K. Vijayraghavan, Q. J. Wang, J. Fan, F. Capasso, S. P. Khanna, A. G. Davies, E. H. Linfield, and M. A. Belkin, “GaAs/Al0.15Ga0.85As terahertz quantum cascade lasers with double-phonon resonant depopulation operating up to 172 K,” Appl. Phys. Lett.97, 131111 (2010). [CrossRef]
  8. S. Kumar, C. W. I. Chan, Q. Hu, and J. L. Reno, “Two-well terahertz quantum-cascade laser with direct intrawellphonon depopulation,” Appl. Phys. Lett.95, 141110 (2009). [CrossRef]
  9. G. Scalari, M. I. Amanti, C. Walther, R. Terazzi, M. Beck, and J. Faist, “Broadband THz lasing from a photon-phonon quantum cascade structure,” Opt. Express8, 8043–8052 (2010). [CrossRef]
  10. A. Wacker, “Extraction-controlled quantum cascade lasers,” Appl. Phys. Lett.97, 081105 (2010). [CrossRef]
  11. B. S. Williams, H. Callebaut, S. Kumar, Q. Hu, and J. L. Reno, “THz quantum cascade laser at λ ≈ 100 μm using metal waveguide for mode confinement,” Appl. Phys. Lett.83, 2124–2126 (2003). [CrossRef]
  12. Q. Hu, B. S. Williams, S. Kumar, H. Callebaut, S. Kohen, and J. L. Reno, “Resonant-phonon-assisted THz quantum-cascade lasers with metal–metal waveguides,” Semicond. Sci. Technol.20, S228–S236 (2005). [CrossRef]
  13. S. Fathololoumi, E. Dupont, S. G. Razavipour, S. R. Laframboise, G. Parent, Z. Wasilewski, H. C. Liu, and D. Ban, “On metal contacts of terahertz quantum-cascade lasers with a metal-metal waveguide,” Semicond. Sci. Technol.26, 105021 (2011). [CrossRef]
  14. M. A. Belkin, Q. J. Wang, C. Pflügl, A. Belyanin, S. P. Khanna, A. G. Davies, E. H. Linfield, and F. Capasso, “High-temperature operation of terahertz quantum cascade laser sources,” IEEE Sel. Top. Quantum Electron.15, 952–967 (2009). [CrossRef]
  15. R. Terrazi and J. Faist, “A density matrix model of transport and radiation in quantum cascade lasers,” New J. Phys.12, 033045 (2010). [CrossRef]
  16. S. Kumar and Q. Hu, “Coherence of resonant-tunneling transport in terahertz quantum-cascade lasers,” Phys. Rev. B80, 245316 (2009). [CrossRef]
  17. E. Dupont, S. Fathololoumi, and H. C. Liu, “Simplified density matrix model applied to three-well terahertz quantum cascade lsers,” Phys. Rev. B81, 205311 (2010). [CrossRef]
  18. S. C. Lee and A. Wacker, “Nonequilibrium Greens function theory for transport and gain properties of quantum cascade structures,” Phys. Rev. B66, 245314 (2002). [CrossRef]
  19. T. Kubis, C. Yeh, P. Vogl, A. Benz, G. Fasching, and C. Deutsch, “Theory of nonequilibrium quantum transport and energy dissipation in terahertz quantum cascade lasers,” Phys. Rev. B79, 195323 (2009). [CrossRef]
  20. H. Callebaut, S. Kumar, B.S. Williams, Q. Hu, and J. L. Reno, “Analysis of transport properties of terahertz quantum cascade lasers,” Appl. Phys. Lett.83, 207–209 (2003). [CrossRef]
  21. H. Callebaut and Q. Hu, “Importance of coherence for electron transport in terahertz quantum cascade lasers,” J. Appl. Phys.98, 104505 (2005). [CrossRef]
  22. C. Jirauschek and P. Lugli, “Monte-Carlo-based spectral gain analysis for terahertz quantum cascade lasers,” J. Appl. Phys.105, 123102 (2009). [CrossRef]
  23. A. Mátyás, M. A. Belkin, P. Lugli, and C. Jirauschek, “Temperature performance analysis of terahertz quantum cascade lasers: Vertical versus diagonal designs,” Appl. Phys. Lett.96, 201110 (2010). [CrossRef]
  24. S. Fathololoumi, E. Dupont, S.R. Laframboise, Z. R. Wasilewski, D. Ban, and H. Liu, “Design of laser transition oscillator strength for THz quantum cascade lasers,” Presented at Conference on Lasers and Electro-Optics, Baltimore, MD (2011).
  25. H. Luo, S. R. Laframboise, Z. R. Wasilewski, and H. C. Liu, “Effects of injector barrier on performance of terahertz quantum-cascade lasers,” IEEE Electron. Lett.43, 633–635 (2007). [CrossRef]
  26. H. Luo, S. R. Laframboise, Z. R. Wasilewski, H. C. Liu, and J. C. Cao, “Effects of extraction barrier width on performance of terahertz quantum-cascade lasers,” IEEE Electron. Lett.44, 630–631 (2008). [CrossRef]
  27. For the density matrix calculations, the electron temperature was chosen 90 K higher than lattice. Pure dephasing time constants of tunneling τ* = 0.35 ps, and of optical intersubband transition τul*=1.1 ps were used. Intrawell intersubband scatterings by LO phonon, e-impurities and interface roughness were considered. The momentum dependance of scattering is averaged over the assumed Maxwell-Boltzmann distribution of carriers in the sub-bands.
  28. S. Fathololoumi, E. Dupont, Z. R. Wasilewski, S. R. Laframboise, D. Ban, and H. C. Liu, “Effect of intermediate resonance on the performance of resonant phonon based terahertz quantum cascade laser,” Presented at 11th International Conference on Intersubband Transitions in Quantum Wells, Badesi, Italy (2011).
  29. S. Fathololoumi, D. Ban, H. Luo, E. Dupont, S. R. Laframboise, A. Boucherif, and H. C. Liu, “Thermal behavior investigation of terahertz quantum-cascade lasers,” IEEE J. Quantum Electron.44, 1139–1144 (2008). [CrossRef]
  30. S. Fathololoumi, E. Dupont, D. Ban, M. Graf, S. R. Laframboise, Z. Wasilewski, and H. C. Liu, “Time-resolved thermal quenching of THz quantum cascade lasers,” IEEE J. Quantum Electron46, 396–404 (2010). [CrossRef]
  31. S. Kumar, “Development of terahertz quantum-cascade lasers,” Massachusetts Institute of Technology163–166 (2007).
  32. C. W. I. Chan, S. Fathololoumi, E. Dupont, Z. R. Wasilewski, S. R. Laframboise, D. Ban, Q. Hu, and H. C. Liu, “A terahertz quantum cascade laser operating up to 193 K,” Presented at 11th International Conference on Intersubband Transitions in Quantum Wells, Badesi, Italy (2011).
  33. The waveguide loss of 22.1 cm−1 was calculated for the Au-Au device without the top n+ layer (∼ 170 μm wide and 1.98 mm long). The estimated cavity loss is, therefore, reduced for ∼ 3 cm−1 (1.9 cm−1 from the waveguide loss and 1.1 cm−1 from the mirror loss), as compared to the estimated cavity loss of the Au-Au device with the top n+ layer (∼ 144 μm wide and 1 mm long), lasing up to 180 K. The MC simulations at 12.8 kV/cm and 3.22 THz showed a gain reduction of ∼ 4 cm−1.
  34. J. Faist, F. Capasso, A. L. Hutchinson, L. Pfeiffer, and K. W. West, “Suppression of optical absorption by electric-field-induced quantum interference in coupled potential wells,” Phys. Rev. Lett.71, 3573–3576 (1993). [CrossRef] [PubMed]
  35. L. A. Dunbar, R. Houdré, G. Scalari, L. Sirigu, M. Giovannini, and J. Faist, “Small optical volume terahertz emitting microdisk quantum cascade lasers,” Appl. Phys. Lett.90, 141114 (2007). [CrossRef]
  36. C. Weber, A. Wacker, and A. Knorr, “Density-matrix theory of the optical dynamics and transport in quantum cascade structures: the role of coherence,” Phys. Rev. B79, 165322 (2007). [CrossRef]
  37. A. Mátyás, P. Lugli, and C. Jirauschek, “Photon-induced carrier transport in high efficiency midinfrared quantum cascade lasers,” J. Appl. Phys.110, 013108 (2011). [CrossRef]
  38. A. Mátyás, T. Kubis, P. Lugli, and C. Jirauschek, “Comparison between semiclassical and full quantum transport analysis of THz quantum cascade lasers,” Physica E42, 2628 (2010). [CrossRef]

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