Abstract
Metal-semiconductor composite nanostructures have become a favored material choice for many nanophotonic applications: from metamaterials to truly nanoscale lasers and SPASERs. The detrimental metal loss is considered the main obstacle, especially for visible and near-infrared wavelengths, for which metal loss is thought to be too great to compensate. Recent work has shown that loss compensation near plasmon resonance is far more complicated, with several counter-intuitive or peculiar effects. In this talk, I will start with the presentation of some unexpected features of semiconductor-metal structures related to the modal gain and confinement factors. After the general discussions of modal properties of metal-semiconductor structures, I will present our experimental results over the last 7 years on semiconductor nanolasers with sub-wavelength sizes using metallic cavities. The results include the first demonstration of an electrical injection nanolaser with a sub-diffraction limit thickness, and especially our recent demonstration of an electrical injection nanolaser operating in continuous wave mode at room temperature. The talk will conclude with some new device designs and comments on the future perspectives.
Speaker Biography
Cun-Zheng Ning received his PhD in Physics from the University of Stuttgart, Germany. He has published over 160 papers 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 120 invited, plenary, or colloquium talks worldwide. He was a senior scientist, nanophotonics group leader, and nanotechnology task manager at NASA Ames Research Centre 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. Dr. Ning is a fellow of the Optical Society (OSA) and of IEEE.
Dr. Ning has made several 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 under electrical injection. Many of his recent achievements are highlighted or reported widely in technology magazines and websites worldwide. Current interests of his group at ASU include nanolasers, on-chip plasmonic sources, nanowire based detectors and solar cells, involving modelling, growth, fabrication, and characterization.