Monday, November 21, 2011

Pushing the Limits of Terahertz Optoelectronics



Seminar: Departmental | December 2 | 3-4 p.m. | Cory Hall, 521 Cory (Hogan Room) UC Berkeley

Mona Jarrahi, Ph.D, University of Michigan, Ann Arbor

Although unique potentials of terahertz waves for chemical identification, material characterization, biological sensing, and medical imaging have been recognized for quite a while, the relatively poor performance, higher costs, and bulky nature of current terahertz systems continue to impede their deployment in field settings. In this talk, I will describe some of our recent results on developing fundamentally new terahertz electronic/optoelectronic components and imaging/spectrometry architectures to mitigate performance limitations of existing terahertz systems.
In specific, I will introduce a new design of high-performance photoconductive terahertz sources that utilize plasmonic antennas to offer wavelength-tunable terahertz radiation at record-high power levels of several tens of milliwatts. I will describe that the unique capabilities of these plasmonic antennas can be further extended to develop heterodyne terahertz spectrometers with single-photon detection sensitivity over a broad terahertz bandwidth (> 5THz) at room temperatures, which has not been possible through existing technologies. To achieve this significant performance improvement, plasmonic antenna and device architectures are optimized for operation at telecommunication wavelengths, where very high power, narrow linewidth, wavelength tunable, compact and cost-effective optical sources are commercially available. Therefore, our results pave the way to compact and low-cost terahertz sources and spectrometers that could offer numerous opportunities for e.g., medical imaging and diagnostics, atmospheric sensing, pharmaceutical quality control, and security screening systems. And finally, I will briefly highlight our research activities on development of other key terahertz electronic/optoelectronic components such as high-sensitivity terahertz detectors based on wave rectification, as well as high power-efficiency terahertz sources based on the use of resonant nonlinear cavities. I will also present new types of high-performance terahertz passive components (modulators, tunable filters, and beam steering devices) based on novel reconfigurable meta-films.

Biography:
Mona Jarrahi received her Ph.D degree in electrical engineering from Stanford University in 2007. During her Ph.D, she focused on optically assisted electronics for millimeter-wave/terahertz applications. Following her Ph.D work, she served as a postdoctoral scholar at Berkeley Sensor and Actuator Center (2007-2008), working on MEMS-based tunable terahertz electronics. She joined University of Michigan in the Fall of 2008, where she is currently an assistant professor of Electrical Engineering, leading the Terahertz Electronics Laboratory. Her research group focuses on Terahertz/Millimeter-Wave Electronics, Optoelectronics, and Imaging/Spectroscopy Systems, Microwave Photonics and Ultrafast Electro-Optics.
Prof Jarrahi is the recipient of numerous awards, including the NSF CAREER Award, the DARPA Young Faculty Award, Robert Bosch FMA fellowship, and best-paper awards at the International Microwave Symposium. Prof. Jarrahi is a member of the program committees of the International Conference on Infrared, Millimeter, and Terahertz Waves, IEEE International Microwave Symposium, International Workshop on Optical Terahertz Science and Technology, as well as the IEEE International Symposium on Antennas and Propagation. She is also a member of the Terahertz Technology and Applications Committee of IEEE Microwave Theory and Techniques Society. She serves as a panelist/reviewer for National Science Foundation and as the vice-chair of technical activities for IEEE Photonics Society, Southeast Michigan Chapter. Prof. Jarrahi is a member of IEEE, OSA, and SPIE.

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