2012

I. Bhattacharya, C. W. I. Chan, and Q. Hu, “Effects of stimulated emission on transport in terahertz quantum cascade lasers based on diagonal designs,” Appl. Phys. Lett. 100, 011108 (2012).
Alan Wei Min Lee, Tsung-Yu Kao, David Burghoff, Qing Hu, and John L. Reno, “Terahertz Tomography Using Quantum-Cascade Lasers,” Opt. Lett. 37, 217 (2012).
Sushil Kumar and Qing Hu, “Investigation of possible microcavity effect on lasing threshold of nonradiative-scattering-dominated semiconductor lasers,” Appl. Phys. Lett. 100, 041105 (2012).
Y. Ren, J. N. Hovenier, M. Cui, D. J. Hayton, J. R. Gao, T. M. Klapwijk, S. C. Shi, T-Y. Kao, Q. Hu, and J. L. Reno, “Frequency locking of single-mode 3.5-THz quantum cascade lasers using a gas cell,” Appl. Phys. Lett. 100, 041111 (2012).
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,” Optics Express, 20, 3866 (2012).
Miriam S. Vitiello, Rita C. Iotti, Fausto Rossi,Alessandro Tredicucci, Qing Hu, and Gaetano Scamarcio, “Non-equilibrium longitudinal and transverse optical phonons in terahertz quantum cascade lasers,” Appl. Phys. Lett. 100, 091101 (2012).
Q. Hu, “Terahertz Quantum Cascade Lasers and Applications,” special seminar, Capital Normal University, Beijing, China, March 26 (2012). (Invited)

Y. Ren, J.N. Hovenier, D.J. Hayton, M. Cui, J.R. Gao, T.M. Klapwijk, S.C. Shi, T-Y. Kao, Q. Hu, and J. L. Reno, “Stabilized HEB-QCL heterodyne spectrometer at super-terahertz”, at the 23rd International Symposium on Space Terahertz Technology, Tokyo, Japan, April 2-4, (2012).

Q. Hu, “THz Quantum Cascade Lasers, Sensing, and Real-Time Imaging,” DTRA CB Defense THz Forum, Falls Church, Virginia, April 3 (2012). (Invited)

2011

S. Kumar, C. W. I. Chan, Q. Hu, and J. L. Reno, "A 1.8 THz quantum-cascade laser operating up to 163 K; significantly above the temperature of ," Nature Physics 7, 166-171 (2011).
David Burghoff, Tsung-Yu Kao, Dayan Ban, Alan Wei Min. Lee, Qing Hu, and John Reno, “A terahertz pulse emitter monolithically integrated with a quantum cascade laser,” Appl. Phys. Lett. 98, 061112 (2011).
Qi Qin, John L. Reno, and Qing Hu, “MEMS-based tunable terahertz wire-laser over 330 GHz,” Opt. Lett. 36, 692 (2011).
Qi Qin and Qing Hu, “MEMS-plunger platform for tunable terahertz wire-laser at ~ 5 K,” J. Micromechanics and Microengineering, 21, 075004 (2011).
Y. Ren, J.N. Hovenier, R. Higgins, J.R. Gao, T.M. Klapwijk, S.C. Shi, , B. Klein, T-Y. Kao, Q. Hu, and J. L. Reno, “High-resolution heterodyne spectroscopy using a tunable quantum cascade laser around 3.5 THz,” Appl. Phys. Lett. 98, 231109 (2011).
J. Gambari, A. I. Fernandez-Dominguez, S. A. Maier, C. C. Phillips, B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, “Thresholdless THz Lasing from a Semiconductor Nanostructure in a Strongly-Coupled Plasmonic Microcavity,” EPS “Nanometa” conference, Seefeld, Austria, January (2011).
Sushil Kumar, Qi Qin, Chun W. I. Chan, Qing Hu, and John L. Reno, “High-temperature performance and broad continuous tunability of terahertz quantum-cascade lasers,” IEEE Phonoics West, San Francisco, CA, 22-27 January (2011). (Invited)
Q. Hu, “Terahertz Quantum Cascade Lasers and Applications,” special seminar, Shanghai Jiao Tong University, Shanghai, China, March 21 (2011). (Invited)
Y. Ren, M.Cui, J.N. Hovenier, J.R. Gao, T.M. Klapwijk, S.C. Shi, T-Y. Kao, Q. Hu, and J. L. Reno, “Frequency locking of a 3.5 THz quantum cascade laser using a gas cell,” 22nd International Symposium on Space Terahertz Technology, Tucson, 26-28 April (2011).
Tsung-Yu Kao; Qing Hu; John Reno, “True Phase-Matched Third-order DFB Terahertz Quantum-Cascade Lasers using Weakly-coupled Cavities,” CLEO/IQEC 2011, CThE4, Baltimore, MD, May 5 (2011).
David Burghoff; Tsung-Yu Kao; Dayan Ban; Alan Lee; John Reno; and Qing Hu, “Gain measurements of a metal-metal terahertz quantum cascade laser using an integrated terahertz pulse emitter,” CLEO/IQEC 2011, CThE5, Baltimore, MD, May 5 (2011).
Qi Qin; Qing Hu; John Reno, “Fast tuning of MEMS-based tunable terahertz wire lasers,” CLEO/IQEC 2011, CThE7, Baltimore, MD, May 5 (2011).
Q. Hu, “Terahertz Quantum Cascade Lasers and Applications,” special seminar, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, China, June 17 (2011). (Invited)
Q. Hu, “Terahertz Quantum Cascade Lasers and Applications”, The 2011 International Symposium on Microwave/Terahertz Science and Applications (MTSA 2011), T1-2, Nanjing, China, June 21 (2011). (Invited)
Y. Ren, M.Cui, J.N. Hovenier, J.R. Gao, T.M. Klapwijk, S.C. Shi, T-Y. Kao, Q. Hu, and J. L. Reno, “Frequency locking of a 3.5 THz quantum cascade laser using a molecular absorption line,” THE 11TH INTERNATIONAL CONFERENCE ON INTERSUBBAND TRANSITIONS IN QUANTUM WELLS (ITQW2011), Sardinia, Italy, September 1-17 (2011).
Y. Ren, J.N. Hovenier, J.R. Gao, T.M. Klapwijk, S.C. Shi, T-Y. Kao, Q. Hu, and J. L. Reno, “High-resolution heterodyne spectroscopy using a tunable quantum cascade laser around 3.5 THz,” THE 11TH INTERNATIONAL CONFERENCE ON INTERSUBBAND TRANSITIONS IN QUANTUM WELLS (ITQW2011), Sardinia, Italy, September 1-17 (2011).
Tsung-Yu Kao, Qing Hu, and John L. Reno, “Perfectly Phase-Matched Third-order DFB THz Quantum-Cascade Lasers,” THE 11TH INTERNATIONAL CONFERENCE ON INTERSUBBAND TRANSITIONS IN QUANTUM WELLS (ITQW2011), Sardinia, Italy, September 1-17 (2011).
David Burghoff, Tsung-Yu Kao, Dayan Ban, Alan Wei Min Lee, John L. Reno, and Qing Hu, “Gain measurements of terahertz quantum cascade lasers using independent mode-matched emitters,” THE 11TH INTERNATIONAL CONFERENCE ON INTERSUBBAND TRANSITIONS IN QUANTUM WELLS (ITQW2011), Sardinia, Italy, September 1-17 (2011).
Chun Wang I. Chan, Saeed Fathololoumi, Emmanuel Dupont, Zbigniew R. Wasilewski, Sylvain R. Laframboise, Dayan Ban, Qing Hu, and H. C. Liu, “A terahertz quantum cascade laser operating up to 193 K,” THE 11TH INTERNATIONAL CONFERENCE ON INTERSUBBAND TRANSITIONS IN QUANTUM WELLS (ITQW2011), Sardinia, Italy, September 1-17 (2011).
Alan Lee, Tsung-Yu Kao, David Burghoff, Q. Hu, and J. L. Reno, "THz optical coherence tomography based on quantum cascade lasers," IRMMW-THz 2011, Houston, TX, October 3-7 (2011). (Invited keynote talk)
Naoki Oda, Alan Lee, and Qing Hu, “Proposal for Real-Time Terahertz Imaging Systems, with Handy Terahertz Camera and Compact Quantum Cascade Laser,” Joint Conference, International Symposium on Terahertz Nanoscience (TeraNano 2011) and Workshop of International Terahertz Research Network (GDR-I), Osaka, Japan, November 24-29 (2011).

2010

S. Kumar and Q. Hu, "Coherence of resonant-tunneling transport in terahertz quantum-cascade lasers," Phys. Rev. B 80, 245316 (2009). Also published in Virtual Journal of Nanoscale Science & Technology, 21(1), January 4, (2010).
A. W. M. Lee, B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Tunable Terahertz Quantum Cascade Lasers with External Gratings," Opt. Lett. 35, 910 (2010).
Q. Hu, "Terahertz Quantum Cascade Lasers and Real-time T-rays Imaging at video rate," J.TST, 2(4), (2010).
T. Y. Kao, Q. Hu, and J. L. Reno, "Phase-Locked Arrays of Surface-Emitting Terahertz Quantum-Cascade Lasers," Appl. Phys. Lett. 96, 101106 (2010).
Christine A. Wang, Anish Goyal, Robin Huang, Joseph Donnelly, Daniel Calawa, George Turner, Antonio Sanchez-Rubio, Allen Hsu, Qing Hu, and B. Williams, "Strain-compensated GaInAs/AlInAs/InP quantum cascade laser material," J. Crystal Growth, 312, 1157-1164 (2010).
J. Gambari, S. A. Maier, B. S. Williams, S. Kumar, J. L. Reno, Q. Hu, and C. C. Phillips, "Thresholdless Coherent Light Scattering from Subband-polaritons in a Strongly-Coupled Microcavity," Phys. Rev. B 82, 121303 (2010).
Sushil Kumar, "Recent Progress in Terahertz Quantum-Cascade Lasers," IEEE Journal of Quantum Electronics, vol, page (2010). (Invited)
Y. Ren, J. N. Hovenier, R. Higgins, J. R. Gao, T. M. Klapwijk, S. C. Shi, A. Bell, B. Klein, T-Y. Kao, S. Kumar, Q. Hu, and J. L. Reno, "Terahertz heterodyne spectrometer using a quantum cascade laser," Appl. Phys Lett. 97, 161105 (2010).
Sushil Kumar, Qing Hu, and J. L. Reno, "Investigation of possible microcavity effect on gain and lasing threshold of semiconductor lasers," submitted to Phys. Rev. A, (2010).
Qing Hu and Alan Wei Min Lee, "Real-Time, Continuous-Wave Terahertz Imaging Using a Microbolometer Focal-Plane Array," U. S. Patent No. 7,692,147, issued on April 6, 2010.
Q. Hu, "Tunable THz lasers," IEEE Winter Topicals 2010, Majorca, Spain. January 11-13 (2010). (Invited)
Q. Hu, " Tunable and high-temperature THz quantum-cascade lasers", IEEE Phonoics West, San Francisco, CA, January 23-28 (2010). [Paper Number: 7616-24] (Invited)
Y. Ren, J. N. Hovenier, R. Higgins, J. R. Gao, T. M. Klapwijk, S. C. Shi, A. Bell, B. Klein, W. Kao, S. Kumar, Q. Hu, and J. L. Reno, "Gas cell measurement using a 2.9 THz heterodyne receiver based on a quantum cascade laser and a superconducting hot electron bolometer," 21ST INTERNATIONAL SYMPOSIUM ON SPACE TERAHERTZ TECHNOLOGY, OXFORD, 23-25 MARCH, (2010).
Y. Ren, P. J. de Visser, J. N. Hovenier, W. Zhang, P. Khosropanah, J. R. Gao, T. M. Klapwijk, S. C. Shi, W. Kao, S. Kumar, Q. Hu, and J. L. Reno, "3.5 THz surface emitting distributed feedback QCL operated at 70 K as local oscillator," 21ST INTERNATIONAL SYMPOSIUM ON SPACE TERAHERTZ TECHNOLOGY, OXFORD, 23-25 MARCH, (2010).
Sushil Kumar, C. W. I. Chan, Q. Hu, and J. L. Reno, "Operation of a 1:8-THz Quantum-Cascade Laser Above 160 K," CLEO/IQEC 2010, CThU1, San Jose, CA, May 20 (2010). (Invited)
Tsung-Yu Kao, Q. Hu, and J. L. Reno, "Phase-Locked Arrays of Surface-Emitting Terahertz Quantum-Cascade Lasers," CLEO/IQEC 2010, CTuMM1, San Jose, CA, May 18 (2010).
Qi Qin, Benjamin S. Williams, Sushil Kumar, Q. Hu, and J. L. Reno, "Development of tunable terahertz wire lasers," CLEO/IQEC 2010, CThU2, San Jose, CA, May 20 (2010).
Q. Hu, "Terahertz Quantum Cascade Lasers and Applications," Waterloo Institute for Nanotechnology seminar, University of Waterloo, Canada, July 15 (2010). (Invited)
S. Kumar, "THz QC lasers: recent progress and future challenges," International Quantum Cascade Lasers School & Workshop, Florence, Italy,  August 30 - September 03 (2010). (Invited tutorial)
Q. Hu, "Tunable THz wire lasers," International Quantum Cascade Lasers School & Workshop, Florence, Italy,  August 30 - September 03 (2010). (Invited)
T. Kao, "Phased array of surface emitting THz QCLs," International Quantum Cascade Lasers School & Workshop, Florence, Italy,  August 30 - September 03 (2010). (Invited)
D. Burghoff, Dayan Ban, S. Kumar, Q. Hu, and J. L. Reno, "Gain measurements of terahertz quantum-cascade lasers with metal-metal waveguides," International Quantum Cascade Lasers School & Workshop, Florence, Italy,  August 30 - September 03 (2010).
C. W. I. Chan, S. Kumar, Q. Hu, and J. L. Reno, "A 1.8 THz Quantum Cascade Laser operating up to 163 K," International Quantum Cascade Lasers School & Workshop, Florence, Italy,  August 30 - September 03 (2010).
Q. Hu, "Terahertz Quantum Cascade Lasers and Their Applications," IRMMW-THz2010, Rome, Italy, September 5-10 (2010). (Invited Plenary Talk)

2009

A. Wade, G. Fedorov, D. Smirnov, S. Kumar, B. S. Williams, Q. Hu, and J. L. Reno, "Magnetic-ﬁeld-assisted terahertz quantum cascade laser operating up to 225 K," Nature Photonics, 3, 41 (2009).
Q. Hu, “Quantum warming,” cover interview, Nature Photonics, 3, 64 (2009).
P. Khosropanah, A. Baryshev, W. Zhang, W. Jellema, J.N. Hovenier, J.R. Gao, T.M. Klapwijk, D.G. Paveliev, B. S. William, S. Kumar, Q. Hu, and J. L. Reno, “Phase-locking of a 2.7-THz quantum cascade laser to a microwave reference,” Opt. Lett. 34, 2958 (2009).
S. Kumar, Q. Hu, and J. L. Reno, “186 K operation of THz quantum cascade lasers based on a diagonal design,” Appl. Phys. Lett. 94, 131105 (2009).
Q. Qin, B. S. Williams, S. Kumar, J. L. Reno, and Q. Hu, “Tuning a Terahertz Wire Laser,” Nature Photonics, 3, 732-737 (2009). Press coverage:
Qing Hu and Benjamin S. Williams, "Terahertz Lasers and Amplifiers Based on Resonant Optical Phonon Scattering to Achieve Population Inversion," U. S. Patent No. 7,548,566, issued on June 16, 2009.
S. Kumar, C. W. I. Chan, Q. Hu, and J. L. Reno, “Two-well terahertz quantum-cascade laser with direct intrawell-phonon depopulation,” Appl. Phys. Lett. 95, 141110 (2009). Also published in Virtual Journal of Nanoscale Science & Technology, 20(16), October 19 (2009).
Qing Hu and Alan W. Lee, “Lens coupled quantum cascade laser,” M.I.T. Case No. 13225. U. S. Patent Application Serial No. 12/437,818. Filed on May 8 (2009).
Qing Hu and Benjamin S. Williams, "Terahertz Lasers and Amplifiers Based on Resonant Optical Phonon Scattering to Achieve Population Inversion," U. S. Patent No. 7,548,566, issued on June 16, 2009.
Qing Hu, “Tunable Wire Laser,” M.I.T. Case No. 14031 (2009). Provisional patent application was filed with the United States Patent and Trademark Office on November 3, 2009.
Q. Hu, “Terahertz quantum cascade lasers and video-rate THz imaging,” International Workshop on Optical Terahertz Science and Technology 2009 (OTST 2009), Santa Barbara, CA, March 7-11, (2009). (Invited)
S. Kumar, Q. Hu, J. L. Reno, “Low-Threshold Terahertz Quantum-Cascade Lasers with One-Well Injector Operating up to 174K,” CLEO/IQEC 2009, CThH4, Baltimore, Maryland, June 4 (2009).
Alan W. M. Lee, Q. Qin, S. Kumar, Q. Hu, J. L. Reno, “Frequency-Tunable External Cavity Terahertz Quantum Cascade Laser,” CLEO/IQEC 2009, CThH5, Baltimore, Maryland, June 4 (2009).
Allen L. Hsu, Q. Hu, and B. S. Williams, “Four-Well Highly Strained Quantum Cascade Lasers Grown by Metal-Organic Chemical Vapor Deposition,” CLEO/IQEC 2009, CThL2, Baltimore, Maryland, June 4 (2009).
Q. Hu, “Terahertz quantum cascade lasers and video-rate THz imaging,” 2009 Advanced Research Workshop (FTM-6), Future Trends in Microelectronics: Unmapped Roads, Sardinia, Italy, June 14-19 (2009). (Invited)
Q. Hu, “Terahertz quantum cascade lasers and video-rate THz imaging,” Device Research Conference (DRC), Penn State University, June 22-24, (2009). (Invited)
Sushil Kumar, I. Chan, Q. Hu, and J. L. Reno, “Terahertz Quantum-Cascade Lasers with Resonant-Phonon Depopulation,” the 10th International Conference on Intersubband Transitions in Quantum Wells (ITQW'09), Montreal, Canada, September 6-11 (2009). (Invited)
P. Khorsropanah, A. Baryshev, W. Zhang, W. Jelleman, J. N. Hovenier, J. R. Gao, T. M. Klapwijk, D. G. Paveliev, S. Kumar, B. S. Williams, Q. Hu, J. L. Reno, B. Klein, and J. L. Hesler, “Phase-locking of a 2.7-THz quantum cascade laser to a microwave reference,” the 10th International Conference on Intersubband Transitions in Quantum Wells (ITQW'09), Montreal, Canada, September 6-11 (2009).
C. A. Wang, A. K. Goyal, R. K. Huang, J. P. Donnelly, D. R. Calawa, G. W. Turner, A. Sanchez-Rubio, A. Hsu, Q. Hu, and B. S. Williams, “GaInAs/AlInAs/InP Quantum Cascade Laser Materials,” the 17th American Conference on Crystal Growth and Epitaxy (17th ACCGE), Lake Geneva, Wisconsin, August 9-14 (2009).
Q. Hu, “Terahertz Quantum Cascade Lasers and Real-time THz Imaging,” ECE seminar, Texas Tech University, Lubbock, TX, October 16 (2009). (Invited)
Q. Hu, “Tunable THz lasers,” TERA-MIR 2009, Turunç-Marmaris, Turkey, November 4 (2009). (Invited)
Q. Hu, “Terahertz quantum cascade lasers and video-rate THz imaging”, Shenzhen International Conferences on Advanced Science and Technology (SICAST), Shenzhen, China, November 15-20 (2009). (Invited)
Q. Hu, “Terahertz Quantum Cascade Lasers and Real-time THz Imaging,” ECE Colloquium, University of Illinois at Urbana-Champaign, IL, December 3 (2009). (Invited)
Q. Hu, “Terahertz Quantum Cascade Lasers and Real-time THz Imaging,” ECE Seminar, Northwestern University, Evanston, IL, December 4 (2009). (Invited)
Q. Hu, “Tunable THz lasers,” Advanced Workshop on 'Frontiers in Electronics' (WOFE). Rincon, Puerto Rico December 13-16, (2009).

2008

Sushil Kumar and Alan W. M. Lee, "Resonant-Phonon Terahertz Quantum-Cascade Lasers and Video-Rate Terahertz Imaging," IEEE Journal of Quantum Electronics, 14, 333 (2008). (Invited)
S. Kumar, A. W. M. Lee, Q. Qin, B. S. Williams, Q. Hu, and J. L. Reno, "High-temperature and high-power operation of terahertz quantum-cascade lasers," SPIE Proceedings (2008).
G. Scamarcio, M. S. Vitiello, V. Spagnolo, S. Kumar, B. S. Williams, and Q. Hu, "Nanoscale heat transfer in quantum cascade lasers," Physica E 40, 1780 (2008).
S. Kumar, A. W. M. Lee, Q. Qin, B. S. Williams, Q. Hu, and J. L. Reno, "High-temperature and high-power operation of terahertz quantum-cascade lasers," IEEE Phonoics West, San Jose, CA, 19 - 24 January (2008). (Invited)
Q. Hu, "Resonant phonon-based THz quantum-cascade lasers and real-time T-rays imaging", International Quantum Cascade Lasers School & Workshop Monte Verita, Switzerland, September 14-19 (2008). (Invited)
S. Kumar, Q. Hu, and J. L. Reno, "Bidirectional Terahertz Quantum-Cascade Lasers", International Quantum Cascade Lasers School & Workshop Monte Verita, Switzerland, September 14-19 (2008).
Alan W.M. Lee, Sushil Kumar, Ben Williams, Qing Hu, and John L. Reno, "Tunable THz QCLs", International Quantum Cascade Lasers School & Workshop Monte Verita, Switzerland, September 14-19 (2008).
Q. Hu, "Terahertz Quantum Cascade Lasers and Real-time THz Imaging ", International Workshop "THz Radiation: Basic Research and Applications" (TERA 2008), Alushta, Crimea, Ukraine, October 2 - 4, (2008). (Invited)
A. Wade, G. Fedorov, D. Smirnov, S. Kumar, Q. Hu, B. S. William, "Magnetic field controlled sub-THz emission in Quantum Cascade Lasers," APS March Meeting, March (2008).
Q. Hu, "Terahertz Quantum Cascade Lasers and Real-time THz Imaging," SUNY at Buffalo EE colloquium, October 23 (2008).
Q. Hu, "THz Quantum Cascade Lasers and sub-surface T-rays Imaging at Video Rate," Terahertz Imaging and Spectroscopy Workshop, Northeastern University, Boston, October 30 (2008). (invited)

2007

Qing Hu and Benjamin S. Williams, "Terahertz Lasers and Amplifiers Based on Resonant Optical Phonon Scattering to Achieve Population Inversion," U. S. Patent No. 7,158,545, issued on January 2, (2007).
Sushil Kumar, B. S. Williams, Q. Qin, A. W. M. Lee, Q. Hu, and J. L. Reno, "Surface-emitting distributed feedback terahertz quantum-cascade lasers in metal-metal waveguides," Optics Express, 15, 113-128 (2007).
Alan Wei Min Lee, Qi Qin, Sushil Kumar, Benjamin S. Williams, Qing Hu, John L. Reno, "High-power and high-temperature THz quantum-cascade lasers based on lens-coupled metal-metal waveguides", Optics Letters, 32, 2840 (2007).
Q. Hu, B. S. Williams, S. Kumar, A. W. M. Lee, Q. Qin, J. L. Reno, H. C. Liu, and Z. R. Wasilewski, "Terahertz Quantum Cascade Lasers and Real-time T-ray Imaging," Future Trends in Microelectronics, Eds. Serge Luryi, Jimmy Xu, Alex Zaslavsky, pp. 347-358, John Wiley & Sons, New York (2007).
V. Spagnolo, M. S. Vitiello, G. Scamarcio, B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Hot-phonon generation in THz quantum cascade lasers," Journal of Physics: Conference Series 92, 012018 (2007).
Qing Hu and Benjamin S. Williams, "Terahertz Lasers and Amplifiers Based on Resonant Optical Phonon Scattering to Achieve Population Inversion," U. S. Patent No. 7,158,545, issued on January 2, 2007.
B. S. Williams, "High-temperature and high-power quantum cascade lasers," IEEE Phonoics West, San Jose, CA, January 23 (2007). [6485-21] (Invited)
Q. Hu, "Terahertz quantum cascade lasers and real-time T-rays imaging," Electrical and Computer Engineering seminar, University of Wisconsin, Madison, April 23 (2007). (Invited)
Benjamin Williams, Sushil Kumar, Qi Qin, Alan Wei Min Lee, Qing Hu, John L. Reno, Z. R. Wasilewski, H. C. Liu, "Terahertz Quantum Cascade Lasers", CLEO/QELS 2007, Baltimore, Maryland, May 9 (2007). (Invited)
Alan W. M. Lee, Qi Qin, Sushil Kumar, Benjamin S. Williams, Qing Hu, John L. Reno, "High-Power Metal-Metal Waveguide Terahertz Quantum-Cascade Laser with a Hyperhemispherical Lens," CLEO/QELS 2007, Baltimore, Maryland, May 9 (2007).
Sushil Kumar, Qi Qin, Benjamin S. Williams, Qing Hu, Zbig R. Wasilewski, Xiaohua Wu, Hui C. Liu, "Quantum-Cascade Lasers with One-Well Injector Operating at 1.59 THz (λ = 188.5 μm)," CLEO/QELS 2007, Baltimore, Maryland, May 9 (2007).
Alan W.M. Lee, Qi Qin, Sushil Kumar, Benjamin S. Williams, Qing Hu, John L. Reno, "Real-Time, Transmission-Mode, Terahertz Imaging over a 25-Meter Distance," CLEO/QELS 2007, Baltimore, Maryland, May 10 (2007).
Sushil Kumar, Benjamin S. Williams, Qi Qin, Alan W. M. Lee, Qing Hu, John L. Reno, "Single-Mode Surface-Emitting Terahertz Quantum Cascade Lasers Operating up to ~ 150 K," CLEO/QELS 2007, Baltimore, Maryland, May 9 (2007).
Q. Hu, "Terahertz quantum-cascade lasers and real-time T-rays imaging," 12th Optoelectronics and Communications Conference, 16th International Conference on Integrated Optics and Optical Fiber Communication," Yokohama, Japan, July 9-13 (2007). (Invited)
V. Spagnolo, M. S. Vitiello, G. Scamarcio, B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Hot-phonon generation in THz quantum cascade lasers," PHONONS2007, July 15-20 (2007).
Q. Hu, "Terahertz quantum-cascade lasers and real-time T-rays imaging," the International Symposium "Topical Problems of Biophotonics-2007", Novgorod-Moscow, Russia, August 4-11 (2007). (Invited)
Q. Hu, "Terahertz quantum-cascade lasers and video-rate THz imaging," IRMMW-THz2007, Cardiff, UK, September 2-7 (2007). (Invited Plenary Talk)
T. O. Klaassen, J. N. Hovenier, A. J. L. Adam, A. Baryshev, J. R. Gao, T. M. Klapwijk, B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "How to manipulate the frequency of a THz QCL?," IRMMW-THz2007, Cardiff, UK, September 2-7 (2007).
Q. Hu, "Terahertz quantum cascade lasers and real-time THz imaging," The 20th Annual Meeting of the IEEE Lasers & Electro-Optics Society (IEEE/LEOS 2007), Orlando, FL, October 21-25, (2007). (Invited)
Gaetano Scamarcio, Miriam S. Vitiello, Vincenzo Spagnolo, Sushil Kumar, Benjamin Williams, and Qing Hu, "Nanoscale heat transfer in quantum cascade lasers," presented at the 13th International Conference on Modulated Semiconductor structures (MSS-13) Genova, Italy, July 15 - 20, 2007. (Invited) Manuscript will be published in Physica E (2007).
A. Wade, G. Fedorov, D. Smirnov, B.S. Williams, and Q. Hu, "LO-phonon assisted injection observed in a THz Quantum Cascade Laser," the 9th International Conference on Intersubband Transitions in Quantum Wells (ITQW'07), Ambleside, Cumbria, U.K., September 9-14, (2007).
S. Kumar, B. S. Williams, Q. Qin, A. W. M. Lee, Q. Hu, J. L. Reno, Z. R. Wasilewski, and H. C. Liu, "Terahertz quantum-cascade lasers with resonant-phonon depopulation: high-temperature and low-frequency operation," the 9th International Conference on Intersubband Transitions in Quantum Wells (ITQW'07), Ambleside, Cumbria, U.K., September 9-14, (2007).
Q. Hu, "THz quantum-cascade lasers and video-rate THz imaging," Photonics Asia, November 11 - 15 (2007), Beijing China. (Invited)
Q. Hu, "Terahertz quantum cascade lasers for video-rate THz imaging," Advanced Workshop on 'Frontiers in Electronics' (WOFE) December 15-19, 2007 Cozumel, Mexico.

2006

E. E. Orlova, J. N. Hovenier, T. O. Klaassen, I. Kasalynas, A. J. L. Adam, A. Baryshev, J. R. Gao, T. M. Klapwijk, B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Antenna Model for Wire Lasers," Phys. Rev. Lett. 96, 173904 (2006). Also published in the May 29, 2006 issue of Virtual Journal of Nanoscale Science & Technology.
B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "High-power terahertz quantum-cascade lasers," Elect. Lett. 42, 89 (2006). Also reported in Compound Semiconductor, page 32, March (2006).
A. J.L. Adam, I. Kašalynas, J.N. Hovenier, T.O. Klaassen, J.R. Gao, E.E. Orlova, B.S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Beam pattern of Terahertz quantum cascade lasers with sub-wavelength cavity dimensions," Appl. Phys. Lett. 88, 151105 (2006). Also published in Virtual Journal of Nanoscale Science & Technology, 13(16), April 26 (2006).
S. Kumar, B. S. Williams, Q. Hu, and J. L. Reno, "1.9-THz quantum-cascade lasers with one-well injector," Appl. Phys. Lett. 88, 121123 (2006).
Alan W.M. Lee, Benjamin S. Williams, Sushil Kumar, Qing Hu, and John L. Reno, "Real-Time Imaging using a 4.3-THz Quantum Cascade Laser and a 320´240 Microbolometer Focal-Plane Array," IEEE Photonics Technology Letters 18, 1415 (2006).
A. Baryshev, J. N. Hovenier, A. J. L. Adam, I. Kasalynas, J. R. Gao, T. O. Klaassen, B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Phase locking and spectral linewidth of a two-mode terahertz quantum cascade laser," Appl. Phys. Lett. 89, 031115 (2006).
B. S. Williams, S. Kumar, Q. Qin, Q. Hu, and J. L. Reno, "Terahertz quantum cascade lasers with double resonant-phonon depopulation," Appl. Phys. Lett. 88, 261101 (2006).
Alan W.M. Lee, Qi Qin, Sushil Kumar, Benjamin S. Williams, Qing Hu, and John L. Reno, 'Real-Time Terahertz Imaging over a Standoff Distance (>25 meters)," Appl. Phys. Lett. 89, 141125 (2006).
Q. Hu, "Terahertz quantum-cascade lasers and real-time T-rays imaging", IEEE Phonoics West, San Jose, CA, January 23 (2006). [6127-08] (Invited)
Q. Hu, "Terahertz quantum-cascade lasers as local oscillators," 17th International Symposium on Space Terahertz Technology (ISSTT 2006), Paris, France, May 10-12 (2006).
Abigail Hedden, Patrick Pütz, Dathon Golish, Christopher Groppi, and Christopher Walker, Benjamin Williams, Qing Hu, and John Reno, "Micromachined Spatial Filters for Quantum Cascade Lasers," 17th International Symposium on Space Terahertz Technology (ISSTT 2006), Paris, France, May 10-12 (2006).
M. Hajenius, J.N. Hovenier, Z.Q. Yang, A. Baryshev, J.J.A. Baselmans, J.R. Gao, T.M. Klapwijk, B.S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Heterodyne receiver based on hot electron bolometer and quantum cascade laser for detection of the OH line at 3.5 THz," 17th International Symposium on Space Terahertz Technology (ISSTT 2006), Paris, France, May 10-12 (2006).
Benjamin S. Williams, Sushil Kumar, Qing Hu, John L. Reno, "High-Power Terahertz Quantum Cascade Lasers," session CTuT2, CLEO/QELS 2006, Long Beach, CA, May (2006).
Sushil Kumar, Benjamin S. Williams, Qing Hu, John L. Reno, "Long Wavelength Terahertz Quantum-Cascade Lasers With One-Well Injector," session CTuT4, CLEO/QELS 2006, Long Beach, CA, May (2006).
Alan W. M. Lee, Sushil Kumar, Benjamin S. Williams, Qing Hu, John L. Reno, "Real-Time Imaging Using a 4.3-THz Quantum Cascade Laser and a 240´320 Element Focal-Plane Array," session CMLL2, CLEO/QELS 2006, Long Beach, CA, May (2006).
Q. Hu, "Terahertz quantum cascade lasers and real-time T-rays imaging," presented at 2006 Advanced Research Workshop on Future Trends in Microelectronics: Up the Nano Creek, Crete, Greece, June 26-30, (2006). (Invited)
Qing Hu, Alan W. M. Lee, Benjamin S. Williams, Sushil Kumar, and John L. Reno, "Real-time THz imaging using quantum-cascade lasers and focal-plane array cameras," Presented at 2nd International Workshop on Quantum Cascade Lasers, Brindisi, Italy, September 6-9 (2006). (Invited)
Benjamin S. Williams, Sushil Kumar, Qi Qin, Alan Lee, Qing Hu, and John L. Reno, "High-temperature and high-power THz quantum cascade lasers," Presented at 2nd International Workshop on Quantum Cascade Lasers, Brindisi, Italy, September 6-9 (2006). (Invited)
Sushil Kumar, Benjamin S. Williams, Qi Qin, Qing Hu, John L. Reno, Z. R. Wasilewski, and H. C. Liu, "Long Wavelength and Surface-emitting Terahertz Quantum-Cascade Lasers," Presented at 2nd International Workshop on Quantum Cascade Lasers, Brindisi, Italy, September 6-9 (2006). (Invited)
Q. Hu, "Terahertz quantum cascade lasers and real-time T-rays imaging," IEEE Sensors 2006, Daegu, Korea, October 22-25 (2006). (Invited)
B. S. Williams, "THz Quantum Cascade Lasers," IEEE LEOS'06 Conference, Montreal, Canada, October (2006). (Invited)

2005

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," a Topical Issue on TERAHERTZ TECHNOLOGY, Journal of Semiconductor Science and Technology, 20, S228-S236 (2005).
S. Kohen, B. S. Williams, and Q. Hu, "Electromagnetic modeling of terahertz quantum cascade laser waveguides and resonators," J. Appl. Phys. 97, 053106 (2005).
M. S. Vitiello, G. Scamarcio, B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Measurement of subband electronic temperatures and population inversion in THz quantum cascade lasers," Appl. Phys. Lett. 86, 111115 (2005).
J. R. Gao, J. N. Hovenier, Z. Q. Yang, J. J. A. Baselmans, A. Baryshev, M. Majenius, T. M. Klapwijk, A. J. L. Adam, T. O. Klassen, B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "A terahertz heterodyne receiver based on a quantum cascade laser and a superconducting bolometer," Appl. Phys. lett. 86, 244104 (2005). Also published in Virtual Journal of Nanoscale Science & Technology, 11(24), June 20 (2005).
H. C. Liu, M. Wächter, D. Ban, Z. R. Wasilewski, M. Buchanan, G. C. Aers, J. C. Cao, S. L. Feng, B. S. Williams, and Q. Hu, "Effect of doping concentration on the performance of terahertz quantum-cascade lasers," Appl. Phys. Lett. 87, 141102 (2005).
A. L. Betz, R. T. Boreiko, B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Frequency and Phaselock Control of a 3-THz Quantum Cascade Laser," Opt. Lett. 30, 1837 (2005).
A. W. M. Lee and Q. Hu, "Real-Time, Continuous-Wave Terahertz Imaging using a Microbolometer Focal-Plane Array," Opt. Lett. 30, 2563 (2005). Also reported in Opto&Laser Europe, page 14, December (2005).
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," Optics Express, 13, 3331-3339 (2005). Also published in Virtual Journal of Nanoscale Science & Technology, 11(25), June 27, (2005).
B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Distributed-feedback terahertz quantum-cascade lasers using laterally corrugated metal waveguides," Opt. Lett. 30, 2909 (2005).
H. Callebaut and Q. Hu, "Importance of coherence for electron transport in terahertz quantum cascade lasers," J. Appl. 98, 104505 (2005). Also published in Virtual Journal of Nanoscale Science & Technology, 12(24), December 12, (2005).
H. C. Liu, H. Luo, D. Ban, M. Wächter, C. Y. Song, Z. R. Wasilewski, M. Buchanan, G. C. Aers, A. J. SpringThorpe, J. C. Cao, S. L. Feng, B. S. Williams, and Q. Hu, "Terahertz Semiconductor Quantum Well Devices," Proc. of SPIE, 6029, 602901 (2005).
Q. Hu, "Terahertz Quantum Cascade Lasers," 8th International Symposium on Contemporary Photonics Technology (CPT2005), Tokyo, Japan, January 13, (2005). (Invited)
B. S. Williams, S. Kohen, S. Kumar, Q. Hu, and J. L. Reno, "Terahertz quantum cascade lasers with metal-metal waveguides," IEEE Phonoics West, San Jose, CA, January 25 (2005). Published in SPIE Proceedings, vol. xxx, yyy (2005). (Invited)
Q. Hu, "Terahertz Quantum Cascade Lasers," Princeton BMD/OOE seminar (Electronics Devices & Materials, Opto & Optoelectronics), Princeton University, NJ, March 7 (2005). (Invited)
A.J.L. Adam, J. N. Hovenier, and T.O. Klaassen, M. Hajenius, J.R. Gao, B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Evaluation of a Quantum Cascade Laser as Local Oscillator for Heterodyne Detection of THz Radiation," OSA topical meeting on Optical Terahertz Science and Technology, Orlando, FL, March 15, (2005).
B. S. Williams, S. Kumar, H. Callebaut, S. Kohen, Q. Hu, and J. L. Reno, "Advances in Terahertz Quantum-Cascade Lasers Using Metal-metal Waveguides," OSA topical meeting on Optical Terahertz Science and Technology, Orlando, FL, March 15, (2005).
A. Betz, R. T. Boreiko, B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Frequency and Phaselock Control of a 3-THz Quantum Cascade Laser," OSA topical meeting on Optical Terahertz Science and Technology, Orlando, FL, March 15, (2005).
Q. Hu, "Terahertz Quantum Cascade Lasers," Harvard EE seminar, Harvard University, MA, April 8 (2005). (Invited)
Q. Hu, "Terahertz Quantum-cascade lasers as local oscillators," 16th International Symposium on Space Terahertz Technology (ISSTT 2005), Göteborg, Sweden, May 2-4 (2005). (Invited)
A.J.L. Adam, J.N. Hovenier, I. Kasalynas, T.O. Klaassen, J.R. Gao, B.S. Williams, S. Kumar, Q. Hu, E.E. Orlova, and J. L. Reno, "Near and Far Field Beam Pattern Measurements on Quantum Cascade Lasers Operating at 2.8 THz," 16th International Symposium on Space Terahertz Technology (ISSTT 2005), Göteborg, Sweden, May 2-4 (2005).
Q. Hu, "Terahertz Devices," Workshop On Compound Semiconductor Devices & Integrated Circuits in Europe (WOCSDICE2005), Cardiff, UK, May 15-18 (2005). (Invited)
Q. Hu, "Terahertz Quantum Cascade Lasers," CLEO/QELS 2005, Baltimore, Maryland, May 22-27 (2005). (Invited)
Miriam Serena Vitiello, Gaetano Scamarcio, Vincenzo Spagnolo, Benjamin S. Williams, Sushil Kumar, Qing Hu, and John L. Reno, "Hot electrons in resonant-phonon terahertz quantum cascade lasers," CLEO/QELS 2005, Baltimore, Maryland, May 22-27 (2005).
Q. Hu, "High-temperature operation of THz quantum-cascade lasers," CLEO Europe 2005, Munich, Germany, June 12-17 (2005). (Invited)
Q. Hu, "THz quantum cascade lasers," 35th Workshop: Physics and Technology of THz Photonics, International School of Solid State Physics, Erice, Italy, July 20-26, (2005). (Invited)
H. C. Liu, H. Luo, D. Ban, M. Wächter, C. Y. Song, Z. R. Wasilewski, M. Buchanan, G. C. Aers, A. J. SpringThorpe, J. C. Cao, S. L. Feng, B. S. Williams, and Q. Hu, "THz Quantum Semiconductor Devices," 20th Congress of the International Commission for Optics, Changchun, China, August 21-26 (2005).
T.O. Klaassen, A.J.L. Adam, N. Hovenier, I. Kasalynas, J-R. Gao, B.S. Williams, S. Kumar, Q. Hu, E. E. Orlova and J. L. Reno, "Optical beam profiles of Terahertz Quantum Cascade Lasers with a metal-metal waveguide: experiment and theory," The 30th International Conference on Infrared and Millimeter Waves and the 13th IEEE International Conference on Terahertz Electronics (IRMMW-THz 2005), Williamsburg, VA, September 19-23, (2005).
Jian-Rong Gao, T.O. Klaassen, A.J.L. Adam, N. Hovenier, I. Kasalynas, B.S. Williams, S. Kumar, Q. Hu, E. E. Orlova and J. L. Reno, "A compact heterodyne receiver at 2.8 THz based on a quantum cascade laser and a superconducting bolometer," The 30th International Conference on Infrared and Millimeter Waves and the 13th IEEE International Conference on Terahertz Electronics (IRMMW-THz 2005), Williamsburg, VA, September 19-23, (2005).
Miriam Serena Vitiello, Gaetano Scamarcio, Vincenzo Spagnolo, Benjamin S. Williams, Sushil Kumar, Qing Hu, and John L. Reno, "Population inversion and thermal properties in resonant-phonon THz quantum cascade laser under CW and pulsed operation," the International Conference on Matter Material and Devices, June 27-July 1, (2005).
S. Kumar, B. S. Williams, Q. Hu, and J. L. Reno, "First-order edge-emitting and second-order surface-emitting distributed feedback terahertz quantum cascade lasers," the 8th International Conference on Intersubband Transitions in Quantum Wells (ITQW'05), Cape Cod, MA, September 11-16, (2005).
B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "High temperature operation of terahertz quantum-cascade lasers," the 8th International Conference on Intersubband Transitions in Quantum Wells (ITQW'05), Cape Cod, MA, September 11-16, (2005).
H. Callebaut and Q. Hu, "Importance of dephasing in electron transport in THz quantum-cascade lasers," the 8th International Conference on Intersubband Transitions in Quantum Wells (ITQW'05), Cape Cod, MA, September 11-16, (2005).
M. S. Vitiello, Gaetano Scamarcio, Vincenzo Spagnolo, Benjamin S. Williams, Sushil Kumar, Qing Hu, and John L. Reno, "Subband electronic temperatures in THz quantum cascade lasers under continuous wave and pulsed operation," the 8th International Conference on Intersubband Transitions in Quantum Wells (ITQW'05), Cape Cod, MA, September 11-16, (2005).
Q. Hu (delivered by B. S. Williams), "Terahertz quantum cascade lasers," IEEE LEOS Terahertz Systems Workshop, Boston, MA, November 9 (2005). (invited)
Q. Hu, "Terahertz quantum-cascade lasers," International Workshop on Terahertz Technology (TeraTech'05), Osaka, Japan, November 17 (2005). (invited)

2004

H. Callebaut, S. Kumar, B. S. Williams, Q. Hu, and J. L. Reno, "Importance of electron-impurity scattering for electron transport in THz quantum-cascade lasers," Appl. Phys. Lett. 84, 645 (2004).
S. Kumar, B. S. Williams, S. Kohen, Q. Hu, and J. L. Reno, "Continuous-wave operation of terahertz quantum-cascade lasers above liquid-nitrogen temperature," Appl. Phys. Lett. 84, 2494 (2004).
B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Resonant-phonon terahertz quantum-cascade laser operating at 2.1 THz (l ≈ 141 µm)," Elect. Lett. 40, 431 (2004).
Hu, Q., B. S. Williams, S. Kumar, H. Callebaut, and J. L. Reno, "Phonon-Depopulated THz Quantum Cascade Lasers,” pp. 319-329, Future Trend in Microelectronics: The Nano, the Giga, and the Ultra, S. Luryi, J. Xu, A. Zaslavsky, eds., John Wiley & Sons, New York, 2004.
Q. Hu, "Resonant-phonon-assisted THz quantum-cascade lasers using metal-metal waveguides for mode confinement," International Workshop on Quantum Cascade Lasers, Servile, Spain, January 4-7, (2004). (Invited)
B. S. Williams, S. Kumar, H. Callebaut, S. Kohen, Q. Hu, and J. L. Reno, "Terahertz quantum cascade lasers using resonant-phonon depopulation and metal-metal waveguides," IEEE Phonoics West, San Jose, CA, January 27 (2004). Published in SPIE Proceedings, vol. xxx, yyy (2004). (Invited)
Q. Hu, "Terahertz Quantum Cascade Lasers," DOE-NSF-NIH Workshop on Opportunities in THz Science, February 12-14, 2004, Sheraton National Hotel – Arlington, VA.
Hu, Q., "Terahertz Quantum-cascade Lasers," presented at the 2004 APS March meeting in session Y2.004, Montreal, Canada, March (2004). (Invited)
A.L. Betz, R.T. Boreiko, B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "A Phase-locked Terahertz Quantum Cascade Laser," presented at the 15th International Symposium on Space Terahertz Technology, Northampton, Massachusetts, April (2004), published in the symposium proceedings, pp (2004).
Hu, Q., "Terahertz Quantum-cascade Lasers," presented at the 2nd International Symposium on Ultrafast Phenomena and Terahertz Waves, Shanghai, China, May (2004). (Invited)
B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Resonant-phonon terahertz quantum cascade lasers at long wavelengths," session CMZ1, CLEO/QELS 2004, San Francisco, CA, May (2004).
S. Kumar, B. S. Williams, S. Kohen, Q. Hu, and J. L. Reno, "High temperature continuous-wave operation of terahertz quantum cascade lasers," session CMZ2, CLEO/QELS 2004, San Francisco, CA, May (2004).
Q. Hu, "Terahertz Quantum Cascade Lasers," presented at the 6th International Conference on Mid-infrared Optoelectronics Materials and Devices (MIOMD-VI), St. Petersburg, Russia, June (2004). (Invited)
Miriam S. Vitiello, Vincenzo Spagnolo, Gaetano Scamarcio, Cinzia Di Franco, Benjamin S. Williams, Sushil Kumar, Qing Hu, John. L. Reno, "Electronic and lattice temperatures of terahertz quantum cascade lasers based on phonon-assisted depopulation," presented at the 6th International Conference on Mid-infrared Optoelectronics Materials and Devices (MIOMD-VI), St. Petersburg, Russia, June (2004).
Miriam S. Vitiello, Vincenzo Spagnolo, Gaetano Scamarcio, Cinzia Di Franco, Michele Sibilano, Benjamin S. Williams, Sushil Kumar, Qing Hu, John. L. Reno, "Measurement of the electron - lattice coupling in terahertz quantum cascade lasers," presented at INFMeeting 2004, Italy, June (2004).
B. S. Williams, S. Kumar, H. Callebaut, Q. Hu, and J. L. Reno, "Resonant-phonon terahertz quantum cascade lasers using metal-metal waveguides," The 29th International Conference on Infrared and Millimeter Waves and the 12th IEEE International Conference on Terahertz Electronics (IRMMW2004/THz2004), Karlruhe, Germany, September 27, (2004). (Invited)
Q. Hu, "Terahertz Quantum Cascade Lasers," 2004 Workshop on Frontiers in Electronics (WOFE'04), Aruba, December 21 (2004).

2003

Q. Hu, "Generation of Terahertz Emission Based on Intersubband Transitions," pp. 57-86, Advanced Semiconductor Heterostructures: Novel Devices, Potential Device Applications and Basic Properties, International Journal of High Speed Electronics and Systems, Vol. 12, No. 4, M. Dutta, and M. A. Stroscio, eds., World Scientific, Singapore, (2003).
B. S. Williams, H. Callebaut, S. Kumar, Q. Hu, and J. L. Reno, "3.4-THz quantum cascade laser based on LO-phonon scattering for depopulation," Appl. Phys, Lett. 82, 1015 (2003). Also published in Virtual Journal of Nanoscale Science & Technology, 7(8), February 24 (2003).
B. S. Williams, S. Kumar, H. Callebaut, Q. Hu, and J. L. Reno, "3.4 THz quantum cascade laser operating above liquid nitrogen temperature," Electro. Lett. 39, 915 (2003).
H. Callebaut, S. Kumar, B. S. Williams, and J. L. Reno, "Analysis of transport and thermal properties of THz quantum cascade lasers," Appl. Phys. Lett. 83, 207 (2003).
J. Montoya and Q. Hu, "LT-GaAs Coplanar Waveguide Single Photon/Two Photon Absorption Autocorrelator," J. Appl. Phys. 95, 2230 (2004). Also published in Virtual Journal of Ultrafast Science, March (2004).
B. S. Williams, S. Kumar, H. Callebaut, Q. Hu, and J. L. Reno, "Terahertz quantum cascade laser at l ≈ 100 µm using metal waveguide for mode confinement," Appl. Phys. Lett. 83, 2124 (2003).
Q. Hu, B. S. Williams, S. Kumar, H. Callebaut, and J. L. Reno, "Terahertz quantum cascade lasers based on resonant phonon scattering for depopulation," Phil. Trans. R. Soc. London A362, 233-249 (2004).
B. S. Williams, S. Kumar, H. Callebaut, Q. Hu, and J. L. Reno, "Terahertz Quantum Cascade Lasers Operating up to 137 K," Appl. Phys. Lett. 83, 5142 (2003).
Q. Hu, "Generation of Terahertz Emission Based on Intersubband Transitions," pp. 57-86, Advanced Semiconductor Heterostructures: Novel Devices, Potential Device Applications and Basic Properties, International Journal of High Speed Electronics and Systems, Vol. 12, No. 4, M. Dutta, and M. A. Stroscio, eds., World Scientific, Singapore, (2003).
Benjamin S. Williams, Hans Callebaut, Sushil Kumar, Qing Hu, and John L. Reno, "Terahertz quantum cascade laser based on direct LO-phonon-scattering depopulation," presented at the 2003 APS March meeting in session X8.013, Austin, TX, March (2003).
Q. Hu, Benjamin S. Williams, Hans Callebaut, Sushil Kumar, and John L. Reno, "Terahertz quantum cascade laser based on LO-phonon-scattering assisted depopulation," presented at the 14th International Symposium on Space Terahertz Technology, Tucson, AZ, April (2003).
B. S. Williams, "Development of THz quantum-cascade lasers'', 33rd Winter Colloquium on The Physics of Quantum Electronics, Snowbird, Utah, January 7, (2003). (Invited)
M. N. Gurnee, L. D. Kimball, and Q. Hu, "Characterization of VOx as a High Performance Microbolometer Detector," presented at 2003 Meeting of the Military Sensing Symposia (MSS) Specialty Group on Detectors, Tucson, Arizona, February 24-28, (2003), published in the symposium proceedings.
Q. Hu, Benjamin S. Williams, Hans Callebaut, Sushil Kumar, and John L. Reno, "Terahertz quantum cascade laser based on LO-phonon-scattering assisted depopulation," presented at SPIE Aerosense Symposium, Orlando, FL, April (2003). (Invited)
B. S. Williams, H. Callebaut, S. Kumar, Q. Hu, and J. L. Reno, "Terahertz quantum cascade laser based on LO-phonon-scattering assisted depopulation," CLEO/QELS 2003, Baltimore, Maryland, June 1-6 (2003).
Q. Hu, "Terahertz quantum cascade lasers based on resonant phonon scattering for depopulation," the Royal Society Scientific Discussion Meeting The terahertz gap: the generation of far-infrared radiation and its applications, London, UK, June 4-5 (2003). (Invited)
Q. Hu, "Terahertz Quantum Cascade Lasers Based on Resonant-Phonon-Scattering-Assisted Depopulation," presented at 2003 Advanced Research Workshop Future Trends in Microelectronics: The Nano, the Giga, the Ultra, and the Bio, Corsica, France, June 23-27, (2003). (Invited)
B. S. Williams, S. Kumar, H. Callebaut, Q. Hu, and J. L. Reno, "Terahertz Quantum Cascade Lasers Based On Resonant-Phonon Depopulation And Using Metal-Metal Waveguides," presented at the 5th International Conference on Intersubband Transitions in Quantum Wells (ITQW'03), Evolene, Switzerland, September (2003).
H. Callebaut, S. Kumar, B. S. Williams, Q. Hu, and J. L. Reno, "Analysis of transport properties of THz quantum cascade lasers," presented at the 5th International Conference on Intersubband Transitions in Quantum Wells (ITQW'03), Evolene, Switzerland, September (2003).
Q. Hu, "Terahertz Quantum Cascade Lasers," Chinese Physical Society Fall Meeting, Hefei, China, September 18-20, (2003). (Invited Plenary Talk)
Q. Hu, "THz quantum cascade lasers based on resonant phonon scattering for depopulation," The 11th IEEE International Conference on Terahertz Electronics (THz2003), Sendai, Japan, September 24-26, (2003). (Invited Plenary Talk)
Q. Hu, "THz quantum cascade lasers based on resonant phonon scattering for depopulation," The 28th International Conference on Infrared and Millimeter Waves (IRMMW2003), Otsu, Japan, September 29 – October 3, (2003). (Invited Plenary Talk)
Q. Hu, "THz quantum cascade lasers based on resonant phonon scattering for depopulation," The 16th Annual Meeting of the IEEE Lasers & Electro-Optics Society (IEEE/LEOS 2003), Tucson, AZ, October 26-30, (2003). (Invited)