摘要

Size reduction has been an ever-lasting theme of nano science and technology. Shrinking the size of photonic devices has been driven both by the rich physics and by promising applications in nanophotonics. Micro cavity lasers have been topics of great interests for several decades in the photonics and physics communities due to their interesting photonic and quantum optical properties and their applications in integrated photonics systems. In the last decade, several microcavity or submicron cavity lasers have been demonstrated such as photonics crystal lasers, microdisk lasers, photonic wire lasers, and nanowire lasers. However, further size reduction of such dielectric-cavity laser becomes exceedingly challenging when the wavelength becomes the fundamental roadblock. To significantly reduce the sizes of semiconductor lasers in all three dimensions beyond the limit of dieletric lasers, a semiconductor-metal core-shell structure was proposed and systematically analyzed with plasmonic resonant behavior included. It was demonstrated by a detailed study taking into account the full plasmonic dispersion that the net modal gain of a semiconductor core can overcome the metal loss in the shell. This was soon verified by the first experimental demonstration of lasing in such a core-shell structure in near infrared by Hill et al.. Since then, experimental and theoretical studies of plasmonic or metallic cavity nanolasers have flourished and rapid progress has been made over the last 5 yeras.

In this talk, we will start with a brief overview of short history and a background introduction to the plasmon-photon interactions, showing how such interactions might lead to a nanolaser of arbitrarily small size. Recent progress in theoretical understanding and experimental demonstration will then be presented systematically, including the first sub-diffraction-limit laser and first CW room-temperature sub-wavelength lasers demonstrated by the speaker’s group.  Special emphasize will be on the unique features of such nanolasers that distinguish them from the conventional lasers of pure dielectric cavities. We will also discuss some of attracting features that are yet to be realized and taken advantage of. The presentation will be concluded with an overview of the futures prospects of nanolasers. 

报告人简介

Cun-Zheng Ning received his PhD (Dr. rer. nat.) in Physics from the University of Stuttgart, Germany, in 1991. He has published 150 papers including 16 in high impact journals such as Physical Review Letters (6, IF=7.6), Nano Letters (5, IF=12)., ACS Nano (2, IF=9.9), Proceedings of National Academy of Sciences (1, IF=9.8), and Advanced Materials (1, IF=10.88), J. Am. Chem. Soc. (1, IF=9.0), in the areas of laser physics, geometric phases, quantum optics, semiconductor optoelectronics, many-body physics in semiconductors, nanophotonics and nanolasers. He has also given over 110 invited, plenary, or colloquium talks worldwide. He was a senior scientist, Nanophotonics Group leader, and Nanotechnology Task manager at NASA Ames Research Center from 1997 to 2007, and an ISSP Visiting Professor at University of Tokyo in 2006. Since 2006, he has been professor of electrical engineering, and Affiliate Professor in Physics and in Materials Science and Engineering at Arizona State University. He was winner of several awards including NASA and NASA contractor Achievement Awards, NASA Space Act Patent Awards, CSC Technical Excellence Award, and IEEE/Photonics Society Distinguished Lecturer from 2007-2009. He has made several pioneering theoretical and experimental contributions in laser physics, nonlinear sciences, and nanophotonics. Notable among them are Ning-Haken or Landsberg-Ning-Haken formalism for geometric phases, stochastic resonances without external forces, first realization of single nanowire infrared laser, first realization of quaternary nanowires, first lasers beyond diffraction limit, and first room temperature operation of subwavelength nanolasers. Many of his recent achievements are highlighted in Science, Nature Photonics, and many other technology magazines worldwide. Current interests of his Nanophotonics Group at ASU include nanolasers, on-chip plasmonic sources, nanowire based detectors and solar cells, involving modelling, growth, fabrication, and characterization. Further information about his group can be found at http://nanophotonics.asu.edu.