OSC Colloquium: Professor Cun-Zheng Ning

    Thursday, September 5, 2019 - 3:30pm - 5:00pm
    Meinel 307

    1630 E. University Blvd.

    3rd Floor Lobby area


    Open to campus and public.


    Speaker: Prof. Cun-Zheng Ning

    Topic: Semiconductor Nanolasers: From Plasmonics to 2D Monolayer Materials

    Host: Rolf Binder

    Visit our website for future lecture dates and speaker information: http://www.optics.arizona.edu/news-events/events/colloquium For a list of our archived lectures: http://www.optics.arizona.edu/news-events/events/colloquium/archive


    Miniaturization has been a constant trend for semiconductor-based technologies such as microelectronics and photonics. One of the most important photonic components in many applications is semiconductor lasers, whose miniaturization is both important and challenging, especially in the future integrated photonic chips for computing and communication. 

    This talk will focus on recent progress in semiconductor nanolasers, or miniaturized lasers down to nanoscales. We will first present an overall introduction on application background and main challenges in laser miniaturization, especially the relationship between sizes, energy efficiency and modulation speed of lasers. The talk will then focus on two active topics of nanolasers: plasmonic nanolasers with sizes significantly below diffraction limit and nanolasers with layered two-dimensional (2D) materials such as transition metal dichalcogenides (TMCs) as gain medium. In the first part, we will show how plasmonic excitation in metals could lead to reduction of laser sizes significantly below those of typical semiconductor cavities.   Such lasers might be potentially important for application in future integrated photonic systems or optical interconnects on the chip. In the second part, we will discuss recent efforts in using 2D layered materials as gain medium for nanoscale lasing. Integration of 2D monolayers with a silicon nanobeam cavity has resulted in our recent demonstration of room temperature lasing based on a single layer of TMCs. Such silicon compatible lasers might provide an important alternative for high energy-efficiency applications in silicon integrated photonics. One of the unresolved issues of 2D TMDCs based lasers is the origin of optical gain. We will discuss how the existence of stable excitons could lead to new gain mechanisms that require only very low levels of carrier injection, important for low energy photonics. We will discuss some of our preliminary results on origin of optical gain in 2D materials.

    Speaker Bio(s): 

    Cun-Zheng Ningreceived his PhD in physics from the University of Stuttgart, Germany. He has published over 190 papers on laser physics, nanophotonics and nanolasers. He has given over 200 invited, plenary, or colloquium talks worldwide. He was a senior scientist, nanophotonics group leader, and nanotechnology task manager at NASA Ames Research Centre (1997-2007), and Visiting Professor at University of Tokyo, Technical University of Berlin and Tsinghua University. Since 2006, he has been a professor of electrical engineering at Arizona State University. He is currently also associated with Tsinghua University. His many awards include several awards from NASA, CSC Technical Excellence Award, and IEEE/Photonics Society Distinguished Lecturer Award. Dr. Ning is a Fellow of the Optical Society (OSA), IEEE, and the Electromagnetic Academy. His many achievements have been widely reported in news media and tech magazines such as Science, Nature Photonics, Science Daily, Laser Focus, Der Spiegel. The first white laser demonstration by his group has won “The Best of Tech in 2015” as the “Top 10 Engineering Invention of the Year” by Popular Science Magazine.


    Refreshments 3:30pm

    Lecture @ 3:45pm - 5pm