Friday, August 16, 2019

Mona Jarrahi: Plasmonics-enhanced terahertz spectroscopy



A plenary talk from SPIE Optics + Photonics 2019
15 August 2019
 

Although unique potentials of terahertz waves for chemical identification and material characterization have been recognized for quite a while, the relatively poor performance of current terahertz spectroscopy and spectrometry systems continue to impede their deployment in field settings.
In this plenary talk, Mona Jarrahi of UCLA describes some of the recent advancements in terahertz spectroscopy systems by using optically-pumped plasmonic photoconductors for terahertz wave generation and detection. Incorporating plasmonic nanostructures inside the active area of photoconductive terahertz sources and detectors offers enhanced quantum efficiencies while maintaining ultrafast operation. This enhancement is due to the unique capability of plasmonic nanostructures to significantly increase the concentration of photo-induced carriers inside the device active area, where they interact with a bias/terahertz electric field to generate/detect terahertz radiation.
By the use of this powerful technique, broadband terahertz spectroscopy with record-high signal-to-noise ratio levels exceeding 140 dB and broadband terahertz spectrometry with quantum-level sensitivities are demonstrated. Such high-sensitivity terahertz spectroscopy and spectrometry systems could offer numerous opportunities for e.g., biomedical sensing, atmospheric studies, astrophysics studies, pharmaceutical quality control, and security screening applications.
Mona Jarrahi received her BS degree in Electrical Engineering from Sharif University of Technology and her MS and PhD degrees in Electrical Engineering from Stanford University. She is currently a professor of electrical and computer engineering and the Director of the Terahertz Electronics Lab at UCLA. Jarrahi has made significant contributions to the development of ultrafast electronic and optoelectronic devices and integrated systems for terahertz, infrared, and millimeter-wave sensing, imaging, computing, and communication systems by utilizing novel materials, nanostructures, and quantum well structures as well as innovative plasmonic and optical concepts.

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