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  • 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.

Lab Director: Benjamin S. Williams

Associate Professor - Department of Electrical Engineering
Member - California NanoSystems Institute (CNSI)

Contact Information:
Department of Electrical Engineering
University of California Los Angeles (UCLA)
68-117 Engineering IV Building
420 Westwood Plaza
Los Angeles, CA 90095-1594
Phone: (310) 825-6961

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Benjamin Williams obtained his B.S. in Physics at Haverford College in 1996, where he performed thesis work on mixing in two-dimensional turbulent fluid  flows, for which he received the American Physical Society Apker prize. He then received his M.S. in 1998 and Ph.D. in 2003 from the Massachusetts Institute of Technology in the department of Electrical Engineering and Computer Science. During this time he developed some of the first terahertz quantum cascade lasers. Prior to joining UCLA, Williams was a Postdoctoral Associate in the Research Laboratory of Electronics at MIT. Since 2007, Prof. Williams has been faculty in the Department of Electrical Engineering at UCLA, and is a Henry Samueli Engineering Fellow. He was awarded a 2008 DARPA Young Faculty Award, the 2012 NSF CAREER award, and the Presidential Early Career Award for Scientists and Engineers (PECASE). He is currently the Area Director for Physical and Wave Electronics in the UCLA EE Department, and serves as the Chair of the Faculty Executive Council for the Henry Samueli School of Engineering and Applied Science (HSSEAS).

Current Members

Postdoctoral Researchers


Sudeep Khanal
Postdoctoral Researcher
Project: Mid-infrared metasurfaces

Sudeep received his Ph.D. in Electrical and Computer Engineering from Lehigh University in 2016 on the topic of novel THz quantum-cascade lasers. 

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Luyao Xu (Zoe)
Postdoctoral Researcher
Project: THz quantum-cascade metasurface lasers

Luyao received her B.S in Optical Engineering at Zhejiang University (PRC) in 2011, and received her Ph.D. in Electrical Engineering at UCLA in 2017.

Graduate Students

Christopher Curwen
Graduate Student Researcher / Ph.D. Candidate
Project: THz metamaterial quantum cascade lasers

Chris received his B.S. in Electrical Engineering from Penn State in 2012 and is currently working towards his Ph.D. in Electrical Engineering at UCLA.

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Yue Shen
Graduate Student Researcher / M. S. Candidate

Yue received his B.Eng. from Tsinghua University in Electronic Engineering in 2016 and is currently working towards his M. S. in Electrical Engineering at UCLA.

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Parastou Mortazavian
Graduate student researcher / M. S. Candidate

Parastou received her B.S. from UCLA in Electrical Engineering in June 2017.

Undergraduate Students

Maxwell Wang
Undergraduae Student Researcher /


Kelvin Cheng
Undergraduae Student Researcher /


Nicholas Echeverry
Undergraduae Student Researcher /


Anthony Kim
Undergraduae Student Researcher /




Alexandros Shailos (postdoc) Currently at Intel Corp.

Zhijun Liu - Currently Professor at University of Electronic Science and Technology of China

Graduate Alumni

Luyao Xu received Ph.D. EE UCLA 2017)
Thesis: Terahertz metasurface quantum cascade laser
Currently a postdoc in our group.

Benjamin Burnett (received Ph.D. EE UCLA 2016)
Thesis: Design and Modeling of High Temperature Terahertz Quantum Cascade Lasers
Currently at Northrop Grumman Corp.

Philip Hon (received Ph.D. EE UCLA 2013)
Thesis: Beam Pattern Engineering of Metamaterial Terahertz Quantum-Cascade Devices
Currently at Northrop Grumman Aerospace Systems

Amir Ali Tavallaee (received Ph.D. EE UCLA 2012)
Thesis: Terahertz Quantum-Cascade Transmission-Line Metamaterials
He received the “Distinguished PhD Dissertation Award in Physical & Wave Electronics” from the UCLA EE Department in 2013. Currently at Mellanox

Partia Naghibi (received M.S. 2013)
Currently at Hughes Research Laboratory and PhD student at UCLA

Jiawei Wang (received M.S. 2017)
Continuing grad school at UCSB

Undergraduate Researcher Alumni

Karan Mehta (B. S. 2010) (Project: Modeling of THz metamaterial waveguides)
He was the recipient of the UCLA EE Dept. 2009-2010 Outstanding Bachelor of Science Award. He continued as a graduate student in EECS at MIT.

Matthew Puckett (B. S. 2011) (Project: Circuit models for CRLH leaky-wave antennas)
Continued as graduate student in EE at UCSD.

Brandon Wu (B.S. 2014)  (Project: Calibration schemes for infrared ellipsometry)
Continued as a grad student in CS at UCLA

Cody Peterson (B. S. 2013) (Project: Electromagnetic simulations of CRLH metamaterial waveguides)
Continued as grad student at Stanford

Jenny Chieu (B.S. 2017) (Project: modeling THz output couplers)

Derrick Chu (B.S. 2015) (Project: Modeling graphene CRLH metamaterial waveguides)
Continued as grad student at Georgia Tech

Daguan Chen (B.S. 2017) (Project: Modeling and design of THz active metasurfaces)
Continued as grad student at UIUC

Susan Krkasharian (Project: Cryogenic optical mount design)


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