Showing posts with label plasmonic antennas. Show all posts
Showing posts with label plasmonic antennas. Show all posts

Wednesday, December 9, 2015

Prof. Mona Jarrahi gave keynote speech entitled New Frontiers in Terahertz Technology at the 15th Mediterranean Microwave Symposiu



http://www.ee.ucla.edu/prof-mona-jarrahi-gave-keynote-speech-entitled-new-frontiers-in-terahertz-technology-at-the-15th-mediterranean-microwave-symposium/

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 new designs of high-performance photoconductive terahertz sources that utilize plasmonic antennas to offer terahertz radiation at record-high power levels of several milliwatts – demonstrating more than three orders of magnitude increase compared to the state of the art. I will describe that the unique capabilities of these plasmonic antennas can be further extended to develop terahertz detectors and heterodyne spectrometers with single-photon detection sensitivities over a broad terahertz bandwidth at room temperatures, which has not been possible through existing technologies. To achieve this significant performance improvement, plasmonic antennas 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, detectors, 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 new types of high-performance terahertz passive components (e.g., modulators, tunable filters, and beam deflectors) based on novel reconfigurable meta-films.
 Biography
Mona Jarrahi received her B.S. degree in Electrical Engineering from Sharif University of Technology in 2000 and her M.S. and Ph.D. degrees in Electrical Engineering from Stanford University in 2003 and 2007. She served as a Postdoctoral Scholar at University of California Berkeley from 2007 to 2008. After serving as an Assistant Professor at University of Michigan Ann Arbor, she joined University of California Los Angeles in 2013 as an Associate Professor of Electrical Engineering and the Director of the Terahertz Electronics Laboratory. Her research group focuses on Terahertz, Millimeter-Wave Electronics and Optoelectronics; Imaging and Spectroscopy Systems; and Microwave Photonics. Prof. Jarrahi has made significant contributions to the development of ultrafast electronic and optoelectronic devices and integrated systems for terahertz 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. In recognition of her outstanding achievements, Prof. Jarrahi has received several prestigious awards in her career including the Presidential Early Career Award for Scientists and Engineers (PECASE); Early Career Award in Nanotechnology from the IEEE Nanotechnology Council; Outstanding Young Engineer Award from the IEEE Microwave Theory and Techniques Society; Booker Fellowship from the United States National Committee of the International Union of Radio Science (USNC/URSI); Grainger Foundation Frontiers of Engineering Award from National Academy of Engineering; Young Investigator Awards from the Army Research Office (ARO), the Office of Naval Research (ONR), and the Defense Advanced Research Projects Agency (DARPA); Early Career Award from the National Science Foundation (NSF); the Elizabeth C. Crosby Research Award from the University of Michigan; and best-paper awards at the International Microwave Symposium and International Symposium on Antennas and Propagation. She has also been named a Kavli Fellow by the National Academy of Sciences. Prof. Jarrahi is actively involved in several professional societies and has been on program committees of several conferences from IEEE, OSA, and SPIE societies. She is a senior member of IEEE, OSA, and SPIE societies and serves as a member of the Terahertz Technology and Applications Committee of IEEE Microwave Theory and Techniques, an editorial board member of Journal of Infrared, Millimeter and Terahertz Waves, a Distinguished Lecturer of IEEE Microwave Theory and Techniques Society, a Traveling Lecturer of OSA, and a Visiting Lecturer of SPIE. In addition, she serves as a panelist and reviewer for National Science Foundation (NSF) and Department of Energy (DOE).

Thursday, May 14, 2015

Abstract-Online Presentation Mona Jarrahi, -New Frontiers in Terahertz Technology





https://nanohub.org/resources/22228

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 new designs of high-performance photoconductive terahertz sources that utilize plasmonic antennas to offer terahertz radiation at record-high power levels of several milliwatts – demonstrating more than three orders of magnitude increase compared to the state of the art. I will also briefly highlight our research activities on development of new types of high-performance terahertz passive components (e.g., modulators, tunable filters, and beam deflectors) based on novel reconfigurable meta-films. 

Mona JarrahiMona Jarrahi received Ph.D. degree in Electrical Engineering from Stanford University in 2007. She served as a Postdoctoral Scholar at University of California Berkeley from 2007 to 2008. After serving as an Assistant Professor at University of Michigan, she joined University of California Los Angeles in 2013 as an Associate Professor of Electrical Engineering and the Director of the Terahertz Electronics Laboratory. In recognition of her outstanding achievements, Prof. Jarrahi has received numerous prestigious awards in her career including the Presidential Early Career Award for Scientists and Engineers (PECASE); Early Career Award in Nanotechnology from the IEEE Nanotechnology Council; Outstanding Young Engineer Award from the IEEE Microwave Theory and Techniques Society. She has also been named a Kavli Fellow by the National Academy of Sciences. Prof. Jarrahi is a senior member of IEEE, OSA, and SPIE societies and serves as a member of the Terahertz Technology and Applications Committee of IEEE Microwave Theory and Techniques, an editorial board member of Journal of Infrared, Millimeter and Terahertz Waves, a Distinguished Lecturer of IEEE Microwave Theory and Techniques Society, and a Visiting Lecturer of SPIE.

Wednesday, January 23, 2013

Abstract-Enhanced terahertz extinction of single plasmonic antennas with conically tapered waveguides



M C Schaafsma1,5, H Starmans1,2, A Berrier1,4 and J Gómez Rivas1,3
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http://iopscience.iop.org/1367-2630/15/1/015006

We demonstrate experimentally the resonant extinction of terahertz (THz) radiation by a single plasmonic bowtie antenna, formed by two n-doped Si monomers with a triangular shape and facing apexes. This demonstration is achieved by placing the antenna at the output aperture of a conically tapered waveguide, which enhances the intensity of the incident THz field at the antenna position by a factor of 10. The waveguide also suppresses the background radiation that is otherwise transmitted without being scattered by the antenna. Bowtie antennas, supporting localized surface plasmons, are relevant due to their ability to resonantly enhance the field intensity at the gap separating the two triangular elements. This gap has subwavelength dimensions, which allows the concentration of THz radiation beyond the diffraction limit. The combination of a bowtie plasmonic antenna and a conical waveguide may serve as a platform for far-field THz time-domain spectroscopy of single nanostructures placed in the gap.

Wednesday, September 5, 2012

Abstract- Selective detection of bacterial layers with terahertz plasmonic antennas




http://cdsweb.cern.ch/record/1475999
Berrier, Audrey ; Schaafsma, Martijn C ; Nonglaton, Guillaume ; Bergquist, Jonas ; Rivas, Jaime Gómez
Current detection and identification of micro-organisms is based on either rather unspecific rapid microscopy or on more accurate complex, time-consuming procedures. In a medical context, the determination of the bacteria Gram type is of significant interest. The diagnostic of microbial infection often requires the identification of the microbiological agent responsible for the infection, or at least the identification of its family (Gram type), in a matter of minutes. In this work, we propose to use terahertz frequency range antennas for the enhanced selective detection of bacteria types. Several microorganisms are investigated by terahertz time-domain spectroscopy: a fast, contactless and damage-free investigation method to gain information on the presence and the nature of the microorganisms. We demonstrate that plasmonic antennas enhance the detection sensitivity for bacterial layers and allow the selective recognition of the Gram type of the bacteria