Prof. Zetian Mi
McGill University
Montreal, Quebec

Recently, semiconductor tubes, formed when a coherently strained semiconductor heterostructure is selectively released from the host substrate, have emerged as a promising technique to realize a new class of nanophotonic devices. They offer many distinct characteristics for laser operation, including ultrahigh Q factors, directional emission, well-defined polarization, and the ability to precisely tailor the confined optical modes using photolithography processes. In this presentation, I will describe the design, fabrication, and characterization of semiconductor tube optical cavities, wherein self-organized InGaAs/GaAs quantum dots are incorporated as the gain media. I will also report on the achievement of the first semiconductor tube lasers in the world, which exhibit an ultralow threshold of ~4 µW at room temperature and tunable emission in the wavelength range of 1.2 - 1.3 µm. Potential applications of semiconductor nanotubes for quantum information processing, biosensing, and solid state lighting will also be discussed.

Zetian Mi is an assistant professor and the Hydro-Quebec Nano-Engineering Scholar in the Department of Electrical and Computer Engineering at McGill University. He received the Ph.D. in Applied Physics from the University of Michigan, Ann Arbor in 2006. He had been a research engineer in Picometrix Inc. (Ann Arbor, MI) from 2001 to 2003 and a postdoctoral researcher in the Department of Electrical and Computer Engineering at the University of Michigan from 2006 to 2007. His research interests are in the areas of epitaxial growth of semiconductor nanostructures, nanophotonics, and nanoelectronics. He is the founder and director of the GaN epitaxial growth facility at McGill University. He has authored over 100 peer-reviewed technical papers and 4 book chapters related to his research and has contributed to a total of 18 invited talks including 2 plenary presentations at international conferences.