物理学院“博约学术论坛”系列报告
第 89 期     ( 2016年第 18期)

报告题目：The Rise of Bosonic Lasers: Optical Devices Spontaneously Emitting Monochromatic And Coherent Light.
报告人：Professor Alexey Kavokin
报告时间：11月24日(周四)上午10:00
报告地点：5#502-1

报告人简介：
Professor Alexey Kavokin, Chair of Nanophysics and Photonics, University of Southampton，United Kingdom.
Scientific research field: Scientific research field: Theory of light-matter coupling in semiconductor hetersotructures: exciton-polaritons. Optics of quantum dots. Microcavities, theory of polariton lasers. Bose-Einstein condensation and superfluidity. Photonic crystals: negative refraction, Bloch oscillations of light. Magnetic polarons. Superconductivity, etc.
Recent works: Spinoptronics, exciton spin transport, quantized vortices, spin textures, spin switches, hybrid Fermi-Bose systems, unconventional superconductivity.
Scientific output: 229 publications in peer reviewed international scientific journals: 1 in Science, 2 in Nature, 3 in Nature Physics, 4 in Nature Photonics, 1 in Nature Communications, 39 in Physical Review Letters; 87 in Physical Review B etc. >10000 citations. h=45 (Web of Science), h=54 (Google scolar).

报告简介：
Bosonic lasers are optical devices spontaneously emitting monochromatic and coherent light. They are based on the Bose-Einstein condensation of light-matter quasiparticles: exciton-polaritons. Recently we have proposed that the emission rate of THz photons may be increased by bosonic stimulation if the THz transition feeds a condensate of exciton-polaritons. The vertical terahertz lasing coexists with polariton lasing and, consequently, is characterised by a low pumping threshold. The resonant two photon pumping of 2p exciton states in such a cavity may be assured by a conventional vertical cavity light emitting diode (VCLED) emitting in red. The terahertz radiation will be emitted due to the transition from 2p-exciton state to 1s exciton-polariton state, which is expected to be stimulated by the occupation number of the 1s state which may achieve 104 in the polariton lasing regime. Further improvement of quantum efficiency of bosonic terahertz lasers may be achieved taking advantage of a cascade effect in a parabolic trap where the THz transition between equidistant exciton energy levels is optically allowed. Bosonic cascade lasers are predicted to achieve quantum efficiencies of 500-700% in realistic structures.