Elliott Brown

Elliott Brown - Wright State University, U.S.A.

Dr. Elliott Brown is a professor of Physics and Electrical Engineering at Wright State University (WSU), Dayton OH, USA.  He is conducting research and teaching courses in THz science and technology, solid-state physics, and antenna theory and technology.  His THz research encompasses ultrafast 1550-nm GaAs photoconductive sources, microwave-to-THz interaction with soft tissue and biomaterials, THz resonant signatures from biomolecules and bioparticles, THz active-system biomedical imaging, and GaN tunneling and light emitting devices.  Prior to WSU Dr. Brown was a Professor of Electrical Engineering at the University of California, (Santa Barbara and Los Angeles campuses), and prior to that was a Program Manager at DARPA in Arlington, VA.  He received a Ph.D. in Applied Physics from the California Institute of Technology in 1985, and did post-doctoral work at MIT Lincoln Laboratory.  He is a Fellow of the IEEE (since 2000) and the APS (since 2007), and in 2010 was selected for the Ohio Research Scholars Endowed Chair in THz Sensors Physics.   In 2015 he was co-author on a best paper award from the IEEE Trans. THz Science and Tech. for “THz sensing of corneal tissue water content: in vivo sensing and imaging results.”

Research stay at UC3M: DEPARTMENT OF SIGNAL THEORY AND COMMUNICATIONS (FEB 2017 - JUL 2017)

Project:

A New Photoconductive THz Local Oscillator, Elliott R. Brown, Ph.D., FIEEE, FAPS, Professor of Physics and Electrical Engineering, Wright State University, Dayton OH,  USA

Dr. Brown’s research for the UC3M Chair of Excellence is the marriage of his GaAs:Er 1550-nm PC-switch technology [1] with the mode-locked VEC-SDL (vertical external cavity, surface disk laser) technology that resides primarily in Europe [2].  It aims to create a quasi-sinusoidal local oscillator operating around 200 GHz and having usefully high power (>> 1 mW), excellent spectral purity, and scalability to higher frequencies, ~1 THz and beyond.  The laser gain medium will be an InGaAs/AlAs multiple-quantum-well (MQW) structure pumped optically at 808 nm with separate diode lasers [3].  A semiconductor saturable absorber mirror (SESAM) is located external to the gain medium and allows for passive mode locking.  An output coupler is located at the opposite angle to the SESAM and has a transmittance of ~1% at 1550 nm. The photoconductive switch is external to the VEC-SDL cavity and has a square-spiral THz antenna, but other antenna types will be explored with the goal of large-signal, complex-conjugate impedance matching [4].  

[1] “ErAs:GaAs THz pulse generation using extrinsic photoconductivity at 1550 nm,” J.R. Middendorf and E.R. Brown,” Optics Express Vol. 20, Issue 15, pp. 16504–16509 (2012).

[2] “200 GHz 1 W semiconductor disc laser emitting 800 fs pulses,” E. J. Saarinen, A. Rantamäki, A. Chamorovskiy, and O. G. Okhotnikov, Electron. Lett., vol. 48, no. 21, pp. 1355–1357, Oct. 2012.

[3] Dr. Esa Saarinen, Tampere University of Technology, Finland, private correspondence.

[4] "Meander Dipole Antenna to Increase CW THz Photomixing Emitted Power," J. Montero-de-Paz, E. Ugarte-Munoz, L.E. Garcia-Munoz, I. Camara Mayorga, and D. Segovia-Vargas, IEEE Trans Antennas and Prop., pp. 4868 - 4872, Vol. 62, Issue 9, Sept. 2014.