Wednesday May 31, 2017 at 2:10 p.m. Kei May Lau, Fang Professor of Engineering and Chair Professor at the Hong Kong University of Science and Technology will be presenting “InAs Quantum Dot Micro-disk Lasers Grown on Exact (001) Si Emitting at Communication Wavelengths”.
Day & Time: Wednesday May 31, 2017
2:10 p.m. – 3:00 p.m.
Speaker: Kei May Lau
Fang Professor of Engineering and Chair Professor
Department of Electronic and Computer Engineering
Hong Kong University of Science and Technology
Location: Room BA 1220
40 St. George Street
Toronto, ON M5S 2E4
Contact: Junho Jeong
Organizers: IEEE Toronto Photonics Society
Abstract: To support an energy-efficient optical interconnect technology enabled by silicon photonics, development of low-energy-consumption active devices and the corresponding integration technology is needed. Most communication wavelength lasers with excellent device performance have been grown on III-V substrates and bonded to silicon. For integration, there are considerable advantages in a technology that allow growth and fabrication of such lasers on III-V/ Si compliant substrates. Quantum dot (QD) active layers grown on lattice-matched substrates have already shown their capability for lasers with low-threshold densities and temperature-independent operation. In addition, the reduced sensitivity of QD to defects and their unique capability of filtering dislocations make them an ideal candidate as the gain medium of hetero-integrated III-V on Si optical sources. In this talk, I will discuss the growth of multi-stack QDs on compliant substrates by MOCVD. Fabrication and laser characteristics of whispering-gallery-mode (WGM) micro-disk lasers using the grown epitaxial structures will also be discussed. Initial demonstration was achieved using simple a colloidal lithography process in combination with dry and wet-etching. The micro-disk lasers were one to four microns in diameter, with single mode lasing at either 1.3 or 1.55 μm, depending on the barrier/cladding system. With smooth sidewalls and sufficient undercut by wet etching of the pedestal, the air-cladded MDs exhibit ultra-low thresholds of a few mW by optical pumping. Preliminary results of electrically-pumped micro-lasers will also be presented. These energy-efficient microlasers are excellent candidates for on-chip integration with silicon photonics.
Biography: Professor Kei May Lau is Fang Professor of Engineering at the Hong Kong University of Science and Technology (HKUST). She received the B.S. and M.S. degrees in physics from the University of Minnesota, Minneapolis, and the Ph.D. degree in Electrical Engineering from Rice University, Houston, Texas. She was on the ECE faculty at the University of Massachusetts/Amherst and initiated MOCVD, compound semiconductor materials and devices programs. Since the fall of 2000, she has been with the ECE Department at HKUST. She established the Photonics Technology Center for R&D effort in III-V materials, optoelectronic, high power, and high-speed devices. Professor Lau is a Fellow of the IEEE, and a recipient of the US National Science Foundation (NSF) Faculty Awards for Women (FAW) Scientists and Engineers (1991) and Croucher Senior Research Fellowship (2008). She is an Editor of the IEEE EDL and Associate Editor of Applied Physics Letters.