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News

  • Dec 2017. Our VECSEL makes the cover of IEEE Journal of Selected Topics in Quantum Electronics.
  • Sept. 2017. Our paper ”High performance terahertz metasurface quantum-cascade VECSEL with an intra-cryostat cavity” is chosen as “Editor’s Pick” in Applied Physics Letters. Link.
  • June 2017. Congratulation to Luyao Xu for receiving her Ph.D., Jiawei Wang and Yujie Lin for receiving their M.S. and to Daguan Chen for receiving his B.S.!
  • May 2017. Luyao Xu has been awarded the UCLA EE Department “Distinguished PhD Dissertation Award in Physical & Wave Electronics” for 2016-17. Congratulations!
  • April 2017. We report metasurface lasers with electrically switchable polarization in Optica. Press release.
  • April 2017. Congratulations to incoming graduate student Parastou Mortazavian on receiving the NSF Graduate Research Fellowship! Link.
  • October 2016. We report high brightness and efficiency THz QC VECSELs with focusing and amplifying metasurfaces. Link.
  • October 2016. Our group is featured in UCLA Engineer Magazine. Link
  • Prof. Williams will give an invited talk at Photonics West 2017, and invited tutorial at OTST 2017. A video of the Photonics West talk is available here.
  • Sept 2016. Congratulations to Dr. Benjamin Burnett for successful completion of his Ph.D. !
  • June 2016. Congratulations to Luyao Xu for being awarded the UCLA Dissertation Year Fellowship for 16/17!
  • Feb 2016. Prof. Williams is awarded a Presidential Early Career Award for Scientists and Engineers (PECASE). Link Link
  • Feb 2016.Congratulations to Luyao Xu for winning the Best Student Presentation Award in the VECSEL Conference at SPIE Photonics West 2016! Link
  • Jan 2016. Press coverage on metasurface VECSEL in Physics Today, Laser Focus World, Photonics.com, Semiconductor Today,
  • September 2015. We report at ITQW 2015 the first demonstration of an external cavity laser based upon an amplifying reflectarray metasurface - a THz VECSEL. It is published in  Applied Physics Letters.
  • 2015. Congratulations to Luyao Xu for winning a 2015 SPIE Optics and Photonics Scholarship!
  • May 2013. Congratulations to Amir Ali Tavallaee, for winning the EE department’s “Distinguished PhD Dissertation Award in Physical & Wave Electronics” for 2012-13!
  • March 2013. Our paper on “Radiation Model for THz  Transmission-Line Metamaterial QC-Lasers” wins 2013 IEEE Trans. THz Science and Technology Best Paper Award.
  • January 2013. We report the first THz active composite right/left handed (CRLH) metamaterial waveguides in Applied Physics Letters.
  • January 2012. Prof. Williams wins NSF CAREER award.
  • April 2011. Our upcoming talk on active THz metamaterial waveguides at SPIE Defense, Security, and Sensing (DSS) Conference is featured in the SPIE Newsroom (April 11 2011).
  • July 2010. Our proposal for THz metamaterial lasers has been covered in Nature Photonics "Research Highlights”.
  • March 2008. Prof. Williams wins DARPA Young Faculty Award.
  • September 2007. Nature Photonics publishes a review paper on THz quantum-cascade lasers.

Review articles

B. S. Williams, "Terahertz quantum cascade lasers." Nature Photonics, vol. 1, September 2007, pp. 517-525.

M. S. Vitiello, G. Scalari, B. S. Williams, and P. DeNatale, “Quantum cascade lasers: 20 years of challenge,”Optics Express, vol 23, 5167-5182 (2015)

Publications

L. Xu, C. A. Curwen, J. L. Reno, and B. S. Williams “High performance terahertz metasurface quantum-cascade VECSEL with an intra-cryostat cavity” Applied Physics Letters, vol. 111, 101101, Sept. 5 2017.

A. Pan, B. A. Burnett, C.-O. Chui, B. S. Williams, “Density Matrix Modeling of Quantum Cascade Lasers without an Artificially Localized Basis: A Generalized Scattering Approach,” Physical Review B, vol. 96, 085308, August 15, 2017.

L. Xu, C. A. Curwen, D. Chen, J. L. Reno, T. Itoh, and B. S. Williams, “Terahertz metasurface quantum-cascade VECSELs: theory and performance,” IEEE Journal of Selected Topics in Quantum Electronics,vol. 23, 1200512, Nov.-Dec. 2017 (Invited paper) . [PDF]

L. Xu, D. Chen, C. A. Curwen, M. Memarian, J. L. Reno, T. Itoh, and B. S. Williams, “Metasurface quantum-cascade laser with electrically switchable polarization,” Optica, vol. 4, 468-475 (2017).  

B. A. Burnett and B. S. Williams, “Design strategy for terahertz quantum dot cascade lasers,” Optics Express, vol. 24,  25471-25481, (2016).  [PDF]

L. Xu, D. Chen, T. Itoh, J. L. Reno, and B. S. Williams, “Focusing metasurface quantum-cascade laser with a near diffraction-limited beam,” Optics Express, vol. 24, 24117-24128 (2016). [PDF]

D. A. Chu, P. W. C. Hon, T. Itoh, and B. S. Williams, “Feasibility of graphene CRLH metamaterial waveguides and leaky wave antennas” Journal of Applied Physics vol 120, 013103 (2016).  [PDF]

B. A. Burnett and B. S. Williams, “Origins of terahertz difference frequency susceptibility in mid-infrared quantum cascade lasers,” Physical Review Applied, vol 5, 034013, 2016 [PDF]

L. Xu, C. A. Curwen, P. W. C. Hon, T. Itoh, B. S. Williams, “Terahertz quantum cascade VECSEL,” Proc. SPIE, vol. 9734, 97340G March 10, 2016)

L. Xu, P. W. C. Hon, C. Curwen, Q.-S. Chen, T. Itoh, and B. S. Williams, “Metasurface external cavity laser,” Applied Physics Letters, vol 107, 221105, 2015 [PDF]

B. A. Burnett and B. S. Williams, "Density matrix model for polarons in a terahertz quantum dot cascade laser," Physical Review B, vol 90, 155309, 2014 [PDF]

P. W. C. Hon, Z. Liu, T. Itoh, and B. S. Williams, "Leaky and bound modes in terahertz metasurfaces made of transmission-line metamaterials," Journal of Applied Physics vol 113, 033105, January 18 2013.[PDF]

A. A. Tavallaee, P. W. C. Hon, Q.-S. Chen, T. Itoh, and B. S. Williams, "Active terahertz quantum-cascade composite right/left-handed metamaterial," Appl. Phys. Lett. vol 102 021103 January 14 2013.[PDF]

P. Senanayake, C.-H. Hung, J. Shapiro, A. Scofield, A. Lin, B. S. Williams, D. L. Huffaker, "3D Nanopillar optical antenna photodetectors," Opt. Express vol 20, pp. 25489-25496, 2012. [PDF]

P. W. C. Hon, A. A. Tavallaee, QiSheng Chen, B. S. Williams, and T. Itoh, "Radiation Model for Terahertz Transmission-Line Metamaterial Quantum-Cascade Lasers," IEEE Trans. Terahertz Science and Technology, vol. 2, no 3, pp. 323-332, May 2012. [PDF]

Z. Liu, P. W. C. Hon, A. A. Tavallaee, T. Itoh, and B. S. Williams, "Terahertz composite right/left handed transmission line metamaterial waveguides,"  Applied Physics Letters vol 100, 071101 February 13, 2012. [PDF]

P. Senanayake, C.-H. Hung, J. Shapiro, A. Lin, B. Liang, B. S. Williams, D. Huffaker, "Surface plasmon enhanced nanopillar photodetectors," Nano Letters vol 11, pp. 5279-5283, 2011. [PDF]

A. A. Tavallaee, B. S. Williams, P. W. C. Hon, T. Itoh, and QiSheng Chen, "Terahertz quantum-cascade laser with active leaky-wave antenna," Applied Physics Letters vol. 99, 141115 October 7, 2011. [PDF]

P.-L. Chi, B. S. Williams, T. Itoh, "Recent progress in application of CRLH structures for active microwave circuits," URSI 2011 Symposium, 13-20 Aug 2011.

B. S. Williams, P. Hon, A. A. Tavallaee, T.Itoh, and QiSheng Chen, "Terahertz QC-lasers and active metamaterial antennas," Proc. SPIE, vol 8031, 80310K (2011).

Y. Ren, J. N. Hovenier, R. Higgins, J. R. Gao, T. M. Klapwijk, S. C. Shi, A. Bell, B. Klein, B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Terahertz heterodyne spectrometer using a quantum cascade laser," Applied Physics Letters, vol. 97, 161105 October 18, 2010.[PDF]

J. Gambari, A. I. Fernandez-Dominguez, 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," Physical Review B, vol 82, 121303(R) 2010.

A. A. Tavallaee, P. Hon, K. Mehta, T. Itoh, and B. S. Williams, "Zero-Index Terahertz Quantum-Cascade Metamaterial Lasers," IEEE J. Quantum Electronics, vol. 46, no 7, July 2010, pp 1091-1098. (paper covered in Nature Photonics "Research Highlights July 2010) [PDF]

A. W. M. Lee, B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Tunable Terahertz Quantum Cascade Lasers with External Gratings," Optics Letters, vol 35, April 1 2010, pp. 910-912. [PDF]

C. A. Wang, A. Goyal, R. Huang, J. Donnelly, D. Calawa, G. Turner, A. Sanchez-Rubio, A. Hsu, Q. Hu, B. Williams, "Strain-compensated GaInAs/AlInAs/InP quantum cascade laser materials,", J. Crystal Growth, vol. 312, pp.1157-1164 (2009).

Q. Qin, B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Tuning a terahertz wire laser," Nature Photonics, vol 3, pp. 732-737. [PDF]

P. Khosropanah, A. Baryshev, W. Zhang, W. Jellem, J.N. Hovenier, J.R. Gao, T.M. Klapwijk, D.G. Paveliev, B. S. Williams, S. Kumar, Q. Hu , J. L. Reno, B. Klein,  J.L. Hesler , "Phase-locking of a 2.7-THz quantum cascade laser to a microwave reference," Optics Letters, vol 34, no 19, Oct 1 2009, pp. 2958-2960. [PDF]

A. Wade, G. Fedorov, D. Smirnov, S. Kumar, B. S. Williams, Q. Hu & J. L. Reno, "Magnetic-field-assisted terahertz quantum cascade laser operating up to 225 K." Nature Photonics, vol 3, Jan 2009, pp. 41-45.  [PDF]

G. Scamarcio, M. S. Vitiello, V. Spagnolo, S. Kumar, B. Williams, Q. Hu,"Nanoscale heat transfer in quantum cascade lasers." Physica E, vol. 40, April 2008, pp. 1780-1784. 

A. W. M. Lee, Qi Qin, S. Kumar, B. S. Williams, Q. Hu, and J. L. Reno, "High-power and high-temperature THz quantum-cascade lasers based on lens-coupled metal-metal waveguides." Optics Letters, vol. 32, 1 October 2007, pp. 2840-2842.[PDF]

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." In Future Trends in Microelectronics: Up the Nano Creek, Wiley, Hoboken, pp. 347-358 (2007). (book chapter)

S. Kumar, B. S. Williams, Qi 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, vol. 15, 8 January 2007, pp. 113. [PDF]

A. W. M. Lee, Qi Qin, S. Kumar, B. S. Williams, Q. Hu and J. L. Reno, "Real-time terahertz imaging over a standoff distance (>25 meters)." Applied Physics Letters, vol. 89, 2 October 2006, pp. 141125. [PDF]

A. Baryshev, J. N. Hovenier, A. J. L. Adam, I. Kašalynas, 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." Applied Physics Letters, vol. 89, 17 July 2006, pp. 031115. [PDF]

B. S. Williams, S. Kumar, Q. Qin, Q. Hu and J. L. Reno, "Terahertz quantum-cascade lasers with double resonant-phonon depopulation." Applied Physics Letters, vol. 88, 26 June 2006, pp. 261101. [PDF]

A. W. M. Lee, B. S. Williams, S. Kumar, Q. Hu and J. L. Reno, "Real-time imaging using a 4.3-THz quantum cascade laser and a 320×240 microbolometer focal-plane array." Photonics Technology Letters, vol. 18, no. 13, 1 July 2006, pp. 1415-1417.[PDF]

E. E. Orlova, J. N. Hovenier, T. O. Klaassen, I. Kasalynas, A. J. L. Adam, J. R. Gao, T. M. Klapwijk, B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Antenna model for wire lasers." Physical Review Letters, vol. 96, 5 May 2006, pp. 173904. [PDF]

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 subwavelength cavity dimensions." Applied Physics Letters. 88, no. 15, 10 April 2006, pp. 151105. [PDF]

S. Kumar, B. S. Williams, Q. Hu and J. L. Reno, "1.9-THz quantum-cascade lasers with one-well injector." Applied Physics Letters, vol. 88, no. 12, 20 March 2006, pp. 121123.

B. S. Williams, S. Kumar, Q. Hu and J. L. Reno, "High-power terahertz quantum-cascade lasers." Electronics Letters, vol. 42, no. 2, 19 January 2006, pp. 89-90. [PDF]

B. S. Williams, S. Kumar, Q. Hu and J. L. Reno, "Distributed-feedback terahertz quantum-cascade lasers with laterally corrugated metal waveguides." Optics Letters, vol. 30, no. 21, November 2005, pp. 2909.

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." Applied Physics Letters, vol. 87, 3 October 2005, pp. 141102.

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." Semiconductor Science and Technology, vol. 20, no. 7, July 2005, pp. S228-36.

A. L. Betz, R. T. Boreiko, B. S. Williams, S. Kumar, Q. Hu and J. L. Reno, "Frequency and phase-lock control of a 3 THz quantum cascade laser." Optics Letters, vol. 30, no. 14, July 2005, pp. 1837-9.

J. R. Gao, J. N. Hovenier, Z. Q. Yang, and J. J. A. Baselmans, A. Baryshev, M. Hajenius, T. M. Klapwijk, A. J. L. Adam, T. O. Klaassen, B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Terahertz heterodyne receiver based on a quantum cascade laser and a superconducting bolometer." Applied Physics Letters, vol. 86, 13 June 2005, pp. 244104.

B. S. Williams, S. Kumar, Q. Hu and J. L. Reno, "Operation of terahertz quantum-cascade lasers at 164 K in pulsed mode and 117 K in continuous-wave mode." Optics Express, vol. 13, no. 9, 3 May 2005, pp. 3331. [PDF]

M. S. Vitiello, G. Scamarcio, V. Spagnolo, and B. S. Williams, S. Kumar, Q. Hu and J. L. Reno, "Measurement of subband electronic temperatures and population inversion in THz quantum-cascade lasers." Applied Physics Letters, vol. 86, no. 11, 14 Mar. 2005, pp. 111115.

S. Kohen, B. S. Williams, and Q. Hu, "Electromagnetic modeling of terahertz quantum cascade laser waveguides and resonators." Journal of Applied Physics, vol. 97, no. 5, 1 Mar. 2005, pp. 053106.

B. S. Williams, S. Kumar, Q. Hu and J. L. Reno, "Resonant-phonon terahertz quantum-cascade laser operating at 2.1 THz ( l » 141 mm)." Electronics Letters, vol. 40, no. 7, 1 Apr. 2004, pp. 431-2.

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." Applied Physics Letters, vol. 84, no. 14, 5 Apr. 2004, pp. 2494-6.

Q. Hu, B. S. Williams, S. Kumar, H. Callebaut, and J. L. Reno, "Terahertz quantum-cascade lasers based on resonant phonon scattering for depopulation." Philosophical Transactions of the Royal Society of London A, vol. 362, 2004, pp. 233-49.

H. Callebaut, S. Kumar, B. S. Williams, Q. Hu and J. L. Reno, "Importance of electron-impurity scattering for electron transport in terahertz quantum cascade lasers." Applied Physics Letters, vol. 84, no. 5, 2 Feb. 2004, pp. 645-7.

B. S. Williams, S. Kumar, H. Callebaut, Q. Hu and J. L. Reno, "Terahertz quantum-cascade laser operating up to 137 K." Applied Physics Letters, vol. 83, no. 25, 22 Dec. 2003, pp. 5142-4.

B. S. Williams, S. Kumar, H. Callebaut, Q. Hu and J. L. Reno, "Terahertz quantum-cascade laser at l ~  100 mm using metal waveguide for mode confinement." Applied Physics Letters, vol. 83, no. 11, 15 Sept. 2003, pp. 2124-6.

H. Callebaut, S. Kumar, B. S. Williams, Q. Hu and J. L. Reno, "Analysis of transport properties of terahertz quantum cascade lasers." Applied Physics Letters, vol. 83, no. 2, 14 Jul. 2003, pp. 207-9.

B. S. Williams, S. Kumar, H. Callebaut, Q. Hu and J. L. Reno, "3.4 THz quantum cascade laser operating above liquid nitrogen temperature." Electronics Letters, vol. 39, no. 12, 12 Jun. 2003, pp. 915-6.

B. S. Williams, H. Callebaut, S. Kumar, Q. Hu and J. L. Reno, "3.4-THz quantum cascade laser based on longitudinal-optical-phonon scattering for depopulation." Applied Physics Letters, vol. 82, no. 7, 17 Feb. 2003, pp. 1015-7. [PDF]

Q. Hu, B. S. Williams, M. R. Melloch, and J. L. Reno, "Terahertz emitters based on intersubband transitions." In Future Trends in Microelectronics, Wiley,New York, pp. 242-52

B. S. Williams, H. Callebaut, Q. Hu, and J. L. Reno, "Magnetotunneling spectroscopy of resonant anticrossing in terahertz intersubband emitters." Applied Physics Letters, vol.79, no.26, 24 Dec. 2001, pp. 4444-6.

B. S. Williams, Q. Hu, "Optimized energy separation for phonon scattering in three-level terahertz intersubband lasers." Journal of Applied Physics, vol.90, no.11, 1 Dec. 2001, pp.5504-11.

B. S. Williams, B. Xu, Q. Hu, M. R. Melloch, "Narrow linewidth terahertz intersubband emission from three-level systems." Applied Physics Letters, vol. 75, no 19, 8 Nov. 1999, pp. 2927-9.

B. S. Williams, D. Marteau, J. P. Gollub, "Mixing of a passive scalar in magnetically forced two-dimensional turbulence." Physics of Fluids, vol.9, no.7, July 1997, pp.2061-80.

Invited Talks    

Benjamin S. Williams,”Terahertz metasurface QC-lasers,” Intersubband Transitions in Quantum Wells (ITQW) 2017, Singapore, September 10-15 2017.

Luyao Xu, Christopher A. Curwen, John L. Reno, and Tatsuo Itoh, Benjamin S. Williams,Terahertz lasers based upon amplifying reflectarray antennas,” URSI GASS 2017, August 2017, Montreal, CA

Luyao Xu, C. A. Curwen, D. Chen, J. L. Reno, T. Itoh, and B. S. Williams, “Terahertz Metasurface Quantum-Cascade VECSEL,” SPIE Optics + Photonics, August 6-10 2017, San Diego, CA.

Benjamin S. Williams, Invited Tutorial Lecture, “Beam engineering in terahertz quantum cascade lasers,” Optical Terahertz Science and Technology (OTST 2017), London, UK 2-7 April 2017.

Benjamin S. Williams, “Terahertz quantum-cascade metasurface VECSELs,” SPIE Photonics West 2017, San Francisco, Feb 1, 2017. Video of conference presentation at http://dx.doi.org/10.1117/12.2251447

Benjamin S. Williams, “Terahertz Lasers Based Upon Metamaterial Concepts,” CLASTECH Symposium and Exhibition, Los Angeles, CA, Oct 28, 2016

Luyao Xu, Christopher Curwen, John Reno, Tatsuo Itoh, and Benjamin S. Williams, “Terahertz metasurface quantum cascade lasers,” 2016 International Conference on Optical MEMS and Nanophotonics (OMN), Singapore, June 30-Aug 4 2016

Luyao Xu,  Philip Hon,  Tatsuo Itoh, and Benjamin S. Williams, “Terahertz quantum cascade metasurface external cavity laser,” Intersubband Transitions in Quantum Wells (ITQW) 2015, Vienna, Austria, September  6-11, 2015.

B. S. Williams, A. A. Tavallaee, P. W. C. Hon, T. Itoh, Qisheng Chen, “Terahertz quantum-cascade lasers with composite right/left handed metamaterial waveguides and antennas,” SPIE Optics+Photonics 2013, August 25-29 2013, San Diego, CA.

B. S. Williams, “Terahertz composite right/left handed metamaterial waveguides,” (Invited Tutorial Lecture), School of Photonics 2013: Where photonics meets electronics, Cortona, Italy, May 20-23 2013.

B. S. Williams, A. A. Tavallaee, P. W. C. Hon, Z. Liu, T. Itoh, “Terahertz quantum-cascade lasers based on transmission-line metamaterial waveguides,” WOCSEMMAD 2013 (Workshop on Compound Semiconductor Materials and Devices), February 18-20, New Orleans 2013.

B. S. Williams, A. A. Tavallaee, P. W. C. Hon, Z. Liu, T. Itoh, Q. Chen, “Terahertz quantum-cascade lasers based on transmission-line metamaterial waveguides,” MIOMD-XI (Mid-Infrared Optoelectronics: Materials and Devices), Sept 4-8 2012, Chicago, IL.

B. S. Williams, A. A. Tavallaee, P. W. C. Hon, Z. Liu, Q. Chen, T. Itoh, "Transmission-line metamaterial antennas for THz quantum-cascade lasers," IMS 2012, Montreal Canada, (June 2012).

B. S. Williams, A. A. Tavallaee, P. W. C. Hon, Zhijun Liu, Q. Chen, T. Itoh, "Terahertz active transmission-line metamaterial antennas," META 2012, Paris, France, (April 2012).

B. S. Williams, Zhijun Liu, Philip W. C. Hon, Amir Ali Tavallaee, QiSheng Chen, Tatsuo Itoh "Terahertz composite right/left handed metamaterials," Physics of Quantum Electronics 2012, Snowbird, Utah (January 2012).

Benjamin S. Williams, Philip Hon, Amir Ali Tavallaee, Tatsuo Itoh, QiSheng Chen, "Terahertz QC-lasers and active metamaterial antennas," 2011 SPIE Defense and Security Sensing (DSS), 25-29 April 2011, Orlando, FL.

Benjamin S. Williams, Amir Ali Tavallaee, Karan Mehta, Philip Hon, Tatsuo Itoh, QiSheng Chen "Active Metamaterial Concepts for Terahertz Quantum-Cascade Lasers," 2010 Workshop on Innovative Devices and Systems (WINDS), 5-10 December 2010, Kohala Coast, HI.

Benjamin S. Williams, Amir Ali Tavallaee, Karan Mehta, Philip Hon, Tatsuo Itoh, "Terahertz quantum-cascade lasers and active terahertz metamaterials" Electrochemical Society (ECS) Meeting, October 2010, Las Vegas, NV.

B. S. Williams, “Zero-Index Terahertz Quantum-Cascade Metamaterial Lasers,”  International Quantum Cascade Lasers School & Workshop  August 30-Sept. 3 2010, Florence Italy.

B. S. Williams, "Terahertz quantum cascade lasers," Asia Optical Fiber Communications & Optoelectronic Exposition & Conference (AOE 2008), Shanghai,China, October 2008.

B. S. Williams, invited tutorial presentation on "Terahertz quantum cascade lasers", GDR-E 2008 Terahertz Workshop, Paris, France, September 2008.

B. S. Williams, "Terahertz quantum cascade lasers for local oscillators", NASA SOFIA SSSC meeting, NASA Ames, Mountain View, CA August 28 2008.

B. S. Williams, S. Kumar, Qi Qin, A. W. M. Lee, H. Callebaut, S. Kohen, Q. Hu, and J. L. Reno, "Terahertz quantum cascade lasers," 2007 Conference on Lasers and Electro-optics (CLEO), Baltimore, MD (May 2007).

B. S. Williams, S. Kumar, Qi Qin, A. W. M. Lee, H. Callebaut, S. Kohen, Q. Hu, and J. L. Reno, "High-temperature and high-power terahertz quantum cascade lasers," SPIE’s Photonics West, San Jose, CA (January 2007).

B. S. Williams, S. Kumar, A. W. M. Lee, H. Callebaut, S. Kohen, Q. Hu, and J. L. Reno, "Terahertz quantum cascade lasers," LEOS Annual Meeting 2006, Montreal, Canada (October 29-Nov 2, 2006).

B. S. Williams, S. Kumar, Q. Qin, A. W. M. Lee, Q. Hu, and J. L. Reno, "Terahertz quantum cascade lasers," 2nd International Workshop on Quantum Cascase Lasers, Maria di Ostuni, Brindisi, Italy (September 6-9, 2006).

B. S. Williams, S. Kumar, A. W. M. Lee, H. Callebaut, S. Kohen, Q. Hu, and J. L. Reno, "Terahertz quantum cascade lasers," IEEE LEOS 2005 Terahertz Systems Workshop, Lexington, MA (November 9, 2005).

B. S. Williams, S. Kumar, H. Callebaut, S. Kohen, Q. Hu, and J. L. Reno, "Terahertz quantum cascade lasers," MIT Center for Integrated Photonic Systems (CIPS) Annual Meeting, Cambridge, MA (May 19-20, 2005).

B. S. Williams, S. Kumar, H. Callebaut, S. Kohen, Q. Hu, and J. L. Reno, "Terahertz quantum cascade lasers," SPIE’s Photonics West, San Jose, CA (January 2005).

B. S. Williams, S. Kumar, H. Callebaut, S. Kohen, Q. Hu, and J. L. Reno, "Resonant-phonon terahertz quantum-cascade lasers using metal-metal waveguides," 2004 Joint 29th International Conference on Infrared and Millimeter Waves (IRMMW) and 12th International Conference on Terahertz Electronics (THZ), Karlsruhe, Germany (September 2004).

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," SPIE’s Photonics West, San Jose, CA (January 2004).

B. S. Williams, H. Callebaut, Q. Hu, and J. L. Reno, "Development of THz quantum-cascade lasers," Physics of Quantum Electronics 2003, Snowbird, Utah (January 2003).

B. S. Williams, "Mixing of a passive scalar in two-dimensional turbulence," 1997 APS/AAPT Joint Meeting, Washington,D.C. (April 1997).

Conference Presentations

Benjamin A. Burnett, Andrew Pan, Prineha Narang, and Benjamin S. Williams, “Robust density matrix modeling of quantum cascade laser kinetics,” Conference on Lasers and Electro-Optics (CLEO 2017), May 14-19 2017, San Jose, CA.

C. A. Curwen, L. Xu, J. L. Reno, T. Itoh, and B. S. Williams, “Broadband continuous tuning of a THz quantum-cascade VECSEL,” Conference on Lasers and Electro-Optics (CLEO 2017), May 14-19 2017, San Jose, CA.

D. Chen, L. Xu, C. A. Curwen, M. Memarian, J. L. Reno, T. Itoh, and B. S. Williams, “Metasurface terahertz laser with electronically controlled polarization,” Conference on Lasers and Electro-Optics (CLEO 2017), May 14-19 2017, San Jose, CA.

L. Xu, C. A. Curwen, D. Chen, T. Itoh, J. Reno, and B. S. Williams, “Focusing Metasurface Quantum-Cascade VECSEL,” Conference on Lasers and Electro-Optics (CLEO 2017), May 14-19 2017, San Jose, CA.

Luyao Xu, Christopher Curwen, Qisheng Chen, John Reno, Tatsuo Itoh, Benjamin S. Williams, “Metasurface quantum-cascade VECSELs from 2.5-3.5 THz,” International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW/THz 2016), September 25-30 2016, Copenhagen, Denmark.

Dingkun Ren, Alan C. Farrell, Xiao Meng, Benjamin S. Williams, and Diana L. Huffaker, “Selective-area InAs-based Nanowires on InP Substrates Towards SWIR/Mid-IR Optical Devices,” Materials Research Society Fall Meeting (MRS 2016), Nov 27-Dec 2, 2016, Boston, MA.

Andrew Pan, Benjamin A. Burnett, and Benjamin S. Williams, “Modeling coherent transport in QCLs without an artificially localized basis,” International Quantum Cascade Laser School and Workshop (IQCLSW 2016), September 4-9 2016, Cambridge, UK (poster presentation).

R. Al Hadi, Y. Zhao, Y. Li, Y. Du, C. Curwen, B. S. Williams, and M.-C. F. Chang, “A Spectral Profiling Method of mm-Wave and Terahertz Radiation Sources,” International Microwave Symposium (IMS 2016) San Francisco, CA, May 22-27 2016

Luyao Xu,  Philip Hon,  Tatsuo Itoh, and Benjamin S. Williams, “Terahertz quantum cascade VECSEL” SPIE Photonics West 2016, San Fransisco, February 13-18 2016. (Awarded Best Student Presentation Award)

Benjamin Burnett and Benjamin S. Williams, “Polaron effects in terahertz quantum dot cascade lasers” Intersubband Transitions in Quantum Wells (ITQW) 2015, Vienna Austria, September  6-11 2015.

Benjamin Burnett  and Benjamin Williams, “Density matrix modeling of terahertz difference frequency generation in dual active-region quantum cascade lasers,” Intersubband Transitions in Quantum Wells (ITQW) 2015, Vienna Austria, September  6-11 2015 (poster presentation).

Benjamin Burnett, Andrew Lin, Diana Huffaker, and Benjamin Williams, “Towards Intersubband nanowire photonics,” Intersubband Transitions in Quantum Wells (ITQW) 2013, Bolton Landing, NY, September 16-20 2013 (poster presentation)

Amir Ali Tavallaee, Philip Hon, Qi-Sheng Chen, Tatsuo Itoh,  and Benjamin Williams, “Terahertz Quantum-Cascade Lasers based on Composite Right/Left-Handed Metamaterials,” 2013 2012 Conference on Lasers and Electro-optics (CLEO), CTu1J.2, San Jose, CA June 10-14 2013.

Philip Hon, Amir Tavallaee, Zhijun Liu, Benjamin Williams, Tatsuo Itoh, "Radiation Modeling of Terahertz Transmission-Line Metamaterial," 2012 Conference on Lasers and Electro-optics (CLEO), QTu3F.8, San Jose, CA (May 6-11 2012).

Zhijun Liu, Philip Hon, Amir Tavallaee, Tatsuo Itoh, and Benjamin Williams, "Terahertz composite right/left-handed transmission-line metamaterial  surfaces," American Physical Society March Meeting, Boston, MA (Feb 27-Mar 2 2012).

Amir Tavallaee, Benjamin S. Williams, Philip Hon, Tatsuo Itoh, Qi-Sheng Chen, "An active terahertz quantum-cascade metamaterial antenna," Intersubband Transitions in Quantum Wells (ITQW) 2011, Sardinia, Italy, September 11-17 2011

Amir Tavallaee, M. Puckett, Benjamin S. Williams, Philip Hon, Tatsuo Itoh, Qi-Sheng Chen, "A Terahertz Quantum-Cascade Laser with an Active Leaky-Wave Metamaterial Antenna," 2011 Conference on Lasers and Electro-optics (CLEO), CThE1, Baltimore, MD (May 1-6 2011).

Amir Ali Tavallaee, Karan Mehta, Benjamin S. Williams, Philip Hon, and Tatsuo Itoh,  "Feasibility of a Terahertz Quantum Cascade Active Metamaterial Based on Composite Right/Left-Handed Transmission-Lines," Intersubband Transitions in Quantum Wells (ITQW) 2009, Montreal Canada, September 7-11.

B. S. Williams, S. Kumar, Q. Qin, Q. Hu, and J. L. Reno, "High-power terahertz quantum cascade lasers," 2006 Conference on Lasers and Electro-optics (CLEO), Long Beach, CA (May 2006).

B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "High-temperature performance of terahertz quantum-cascade lasers," 8th International Conference on Intersubband Transitions in Quantum Wells (ITQW), Cape Cod, MA (Sept. 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," 2005 Optical Terahertz Science and Technology (OTST), Orlando, FL (March 2005).

B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Resonant-phonon terahertz quantum cascade lasers at long wavelengths," 2003 Conference on Lasers and Electro-optics (CLEO), Baltimore, MD (June 2003).

B. S. Williams, S. Kumar, H. Callebaut, Q. Hu, and J. L. Reno, "Terahertz quantum cascade laser based on resonant-phonon depopulation and using metal-metal waveguides," 7th International Conference on Intersubband Transitions in Quantum Wells (ITQW), Evolčne, Switzerland (Sept. 2003).

B. S. Williams, H. Callebaut, S. Kumar, Q. Hu, and J. L. Reno, "Terahertz quantum cascade laser based on LO-phonon-scattering assisted depopulation," 2003 Conference on Lasers and Electro-optics (CLEO), Baltimore, MD (June 2003).

B. S. Williams, H. Callebaut, S. Kumar, Q. Hu, and J. L. Reno, "Terahertz quantum cascade laser based on direct LO-phonon-scattering depopulation," 2003 APS March Meeting, Austin, TX (March 2003).

B. S. Williams, Hans Callebaut, Q. Hu, M. R. Melloch, and J. L. Reno, "Terahertz intersubband emission in structures with and without LO-phonon assisted depopulation," 6th International Conference on Intersubband Transitions in Quantum Wells (ITQW), Asilomar, California (Sept 2001).

B. S. Williams, B. Xu, Q. Hu, and M. R. Melloch, "Narrow-linewidth interwell THz intersubband emission," 8th International Conference on Terahertz Electronics, Darmstadt, Germany (September 2000).

B. S. Williams, B. Xu, Q. Hu, and M. R. Melloch, "Narrow linewidth terahertz intersubband emission from three-level multiple quantum well structures," 5th International Conference on Intersubband Transitions in Quantum Wells (ITQW), Bad Ischl, Austria (Sept 1999).

B. S. Williams, B. Xu, Q. Hu, and M. R. Melloch, "Terahertz intersubband emission from cascaded multiple quantum well structures," SPIE's International Symposium on Optical Science, Engineering, and Instrumentation, Denver, CO (July 1999).

B. S. Williams, B. Xu, Q. Hu, and M. R. Melloch, "Narrow linewidth terahertz intersubband emission," 1999 APS March Meeting, Atlanta, GA (March 1999).

B. S. Williams, B. Riely, Q. Hu, and M. R. Melloch, "Mid-infrared GaAs/AlGaAs based quantum cascade emitters," TMS 40th Electronic Materials Conference, Charlottesville, VA (June 1998).

B. S. Williams, B. Riely, Q. Hu, and M. R. Melloch, "Mid-infrared quantum cascade lasers," 1998 APS March Meeting, Los Angeles, CA (March 1998).

 

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