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

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.

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.