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On-chip Whispering Gallery Optical Resonators and Microlasers: A tool for detecting and measuring single particles and single molecules

2011-10-12 (Wed) 2:00 p.m. - 3:00 p.m.

This seminar deals with new imaging technology that was developed based on research into the phenomena of the mysterious behavior of sound waves in the Whispering Gallery in Saint Paul's Cathedral in London.

Title: On-chip Whispering Gallery Optical Resonators and Microlasers: A tool for detecting and measuring single particles and single molecules

Lecturer: Şahin Kaya Özdemir, PhD., Department of Electrical and Systems Engineering, Washington University in St. Louis, Missouri, USA
Abstract: Whispering-Gallery-Mode (WGM) optical microresonators, with their microscale mode volumes and ultra-high-quality factors, have shown great promise for applications in various fields of science, spanning from optomechanics and frequency combs to on-chip microcavity lasers and label-free bio-chemical sensing. In this talk, after briefly introducing the physical concepts behind these resonators, I will highlight some of the milestone applications with an emphasis on bio-chemical sensing with ultra-high-resolution. Then I will report a new sensing method that we have developed for the detection and measurement of individual nanoparticles. Contrary to the conventional approach of monitoring spectral changes in a single resonance, this new technique rely on the splitting of a single resonance mode into two resonances upon perturbations within close proximity of the resonator. I will first present the results of experiments using passive WGM microtoroid resonators, with which polystyrene nanoparticles down to 20nm and individual Influenza virions could be detected and measured one-by-one with a single shot measurement [1]. Then, I will show how the detection limit can be improved to reach down to 15nm for polystyrene, 10nm for gold nanoparticles, by incorporating a gain medium (rare earth ions such as erbium and ytterbium) into the resonator and using it as a microlaser [2]. I will end the talk with a discussion on some of the opportunities and challenges.


Bibliography:

  1. J. Zhu, S. K. Ozdemir, Y.-F. Xiao, L. Li, L. He, D.-R. Chen & L. Yang, Nature Photonics 4, 46 - 49 (2010)

  2. L. He, S. K. Ozdemir, W. Kim, J. Zhu, & L. Yang, Nature Nanotechnology 6,428–432 (2011)


Date: 2011-10-12 (Wed) 2:00 p.m. - 3:00 p.m.
Organizer: Immunology Frontier Research Center (IFReC)
Venue: Meeting Room 1, IFReC Research Bldg. 2 F, Immunology Frontier Research Center (IFReC)
Registration: Not necessary.
URL: http://www.ifrec.osaka-u.ac.jp/jpn/activities/2011/09/111012-ozdemir.php
Contact: Immunology Frontier Research Center (IFReC)
j-sakano@ifrec.osaka-u.ac.jp

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