Keynote 7 | Nanoultrasonics Based on Piezoelectric Superlattices |
Date/Time | Saturday, 4 May 2013 / 08:30 – 09:10 |
Venue | Riverfront Ballroom |
Prof. Chi-Kuang SUN
National Taiwan University, Taiwan
Biography
Chi-Kuang Sun received the Ph.D. degree in applied physics from Harvard University in 1995
and is now a life distinguished professor of the Graduate Institute of Photonics and Optoelectronics
and Department of Electrical Engineering at National Taiwan University (NTU),
where he also serves as the Chief Director of Molecular Imaging Center. He established the
NTU Ultrafast Optics Group and his research interest is primarily concerned with nano-acoustics, femtosecond
laser technology, THz optoelectronics, and biomedical optics. Dr. Sun is a fellow of OSA, IEEE, and SPIE.
Abstract
Piezoelectric semiconductor strained superlattices can be treated as piezoelectric transducers to generate
nanometer-wavelength and THz-frequency acoustic waves. In this talk, I will review the mechanism and realization
of nano-acousticwave (NAW) generation in strained piezoelectric layers induced by femtosecond optical
pulses, which can be modeled by a macroscopic elastic continuum theory. The optical absorption change of the
strained layers modulated by NAW through quantum-confined Franz-Keldysh effects allows optical detection
of the propagating NAW. Based on these piezoelectric-based optical principles, we have successfully designed
several optical piezoelectric transducers to generate NAW for high frequency acoustic spectroscopy and high
spatial resolution imaging.