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  • Optically-Controlled Tunable/Reconfigurable Terahertz Devices for Advanced Sensing, Imaging and Communications

    Seminar Title  

    Optically-Controlled Tunable/Reconfigurable Terahertz Devices for Advanced Sensing, Imaging and Communications

    Speaker:  Dr. LIU Lei


     (University of Notre Dame)


    Monday afternoon, July 1, 15:30 p.m.



    Room 216 No.5  building , Xianlin campus (PMO, CAS)

                             Welcome to Attend   

      ( PMO Academic Committee & Academic Circulating committee)


    Adstract Tunable and reconfigurable terahertz (THz) devices (e.g., modulators, variable attenuators, tunable filters, coded apertures, phase shifters and high-level switches (e.g., SPDT, DPDT) ) that are required for advanced sensing, imaging and adaptive wireless communication applications are challenging to realize. In this talk, I will present a promising novel approach to develop the above THz devices based on spatially-resolved optical modulation (SROM) using photo-induced (PI) free carriers in semiconductors. The fundamental mechanism for this approach will first be introduced followed by prototype demonstrations (i.e., waveguide-based tunable attenuators, reconfigurable coded-aperture imaging masks, beam steering/forming antennas), The potential to develop more advanced tunable/reconfigurable THz devices (e.g., tunable delay lines, SPDT, DPDT switches) using optically-controlled waveguide architectures such as PI electromagnetic band gap (EBG) structures and dynamically-reconfigurable PI substrate-integrated waveguides (SIWs) will also be discussed on the basis of performance-improved SROM using the so-called mesa-array technique. Finally, high-performance optically-controlled RF switches enabling a novel class of reconfigurable mmW-THz circuits will also be analyzed and discussed.

      Dr. Liu (S'99-M'07-SM'18) received the B.S. and M.S. degrees in electrical engineering from Nanjing University, Nanjing, China, in 1998 and 2001, respectively, and the Ph.D. degree in electrical engineering from the University of Virginia, Charlottesville, VA, in 2007. 

      From 2007 to 2009, he was a Post-Doctoral Research Associate with the Department of Electrical and Computer Engineering, University of Virginia. In September 2009, he joined the faculty of the University of Notre Dame, where he is currently a tenured Associate Professor of Electrical Engineering. His research interests include millimeter- and submillimeter-wave device and circuit design, modeling, and testing, quasi-optical techniques, terahertz detectors for imaging and spectroscopy, novel microwave materials and devices, superconducting electronics, microfabrication and processing.

      Dr. Liu is a Senior Member of the IEEE, the HKN honor society, and a member of IEEE Microwave Theory and Techniques (MTT) society. He has published ~120 journal and conference papers, and received more than 3000 peer citations. Dr. Liu is a reviewer for a variety of journals including Nature Communications, IEEE Trans. Microwave Theory & Tech., IEEE Trans. Terahertz Science & Tech., IEEE Microwave and Wireless Components Lett.. He served as a session chair for the IEEE ASC conference (2006), session co-chair for IEEE International Microwave Symposium (IMS 2015, IMS 2018). Dr. Liu is the recipient of the prestigious IEEE MTT-S THz Prize (IEEE Trans. THz Sci. & Technol. Best Paper Award) in 2019. His students won the 2012 IEEE Asia-Pacific Microwave Conference (APMC, Taiwan) Student Prize, the 2012 International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz, Wollongong, Australia) Best Student Paper Award, and the 2015 IEEE MTT-S Graduate Fellowship Award.

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