Seminar Announcement 1/3: Nanomechanically coupled photonic cavities and their application

  • 2019-01-01
  • 書報討論

主題(Topic)：

Nanomechanically coupled photonic cavities and their application

 
講者(Speaker)：
Dr. Zhou Guangya, Assistant Professor, Mechanical Engineering, National University of Singapore

時間(Date)：
1/3 (四)3:30pm – 5:00pm

地點(Venue)：
工程五館B1國際會議廳(EEB24)

Engineering Building 5 B1 International Conference Hall

Abstract:

In this talk, I will first highlight some of our recent developments in miniature solid tunable optics including microelectromechanical systems (MEMS)-driven apertures and MEMS-tunable solid lenses. The solid tunable lenses use Alvarez-Lohmann principle, where small lateral movements of two specially-designed free-form optical elements arranged in tandem one immediately behind another can achieve large variations in the overall optical power of the combination. Comparing to liquid-tunable lenses and liquid crystal lenses, such MEMS-tunable solid lenses are mechanical stable and easy of packaging and handling processes without potential leakage and evaporation problems. We have implemented such miniature solid tunable lenses in dual-element and multi-element forms using a combination of diamond turning precision machining, soft lithography, and SOI micromachining technologies. I will further discus the applications of miniature solid tunable optics in compact smart endoscopes for autofocusing and zooming.
 
I will then talk about tunable nanophotonic resonators using on-chip integrated nanoelectromechanical systems (NEMS) actuators. Photonic nano resonator or nano cavity has attracted much attention and becomes increasingly important to a range of nanophotonic applications, including efficient and ultra-compact lasers, nano scale wavelength-selective add/drop multiplexers, optical filters, and high-sensitive sensors. Making nanophotonic resonators tunable is attractive, as tunable nano resonators can provide not only greater flexibility in a dynamic photonic system and but also post-process compensation capability for fabrication imperfections. Tuning nanophotonic resonators with NEMS offers outstanding advantages including low power consumption, large tuning range, absence of exotic materials, and compatible with silicon micro/nano-fabrication processes. I will introduce the NEMS tuning approaches we developed for such resonators, these include: 1) Resonance tuning through cavity evanescent field perturbation using a NEMS-driven dielectric nano probe, 2) Resonance wavelength splitting/shifting/tuning of coupled nano resonators through NEMS-induced coupling strength variation, 3) Resonance tuning by resonator’s nano-deformation driven by NEMS.
 

About the speaker:

Guangya Zhou received his B.Eng. and Ph.D. degrees in optical engineering from Zhejiang University, Hangzhou, China, in 1992 and 1997, respectively. He joined the Department of Mechanical Engineering, National University of Singapore (NUS) in 2005 as an assistant professor. And from 2012, he is a tenured associate professor in the same department. His research interests include optical MEMS scanners, MEMS spectrometers and hyperspectral imagers, optical MEMS based ultra-compact endoscope probes, silicon nanophotonics, NEMS tunable photonic crystals, and nano scale optomechanics. He has published over a hundred research papers in peer-reviewed international journals in his field. He is the main inventor of the MEMS-driven vibratory grating scanner, MEMS-based miniature zoom lens system with autofocus function, and miniature MEMS-based adjustable aperture.