SOCRATES; Solid state optical cooling with rare earth and quantum doT dopEd glasses and crystals and in semiconductors

点击翻译按钮获取中文摘要

SOCRATES: Solid state Optical Cooling in RAre earth and quantum doT dopEd glasses and crystals and in Semiconductors The objectives of the research proposal are to study and implement novel techniques for laser induced cooling of solid-state materials. Laser induced cooling of solids is a technique to remove phonon energy by adding it to a low energy pump wavelength, and emitting it as higher energy anti-Stokes (AS) radiation. Our previous work proposed several theoretical techniques for the efficient removal of energy, for example by optimising the geometry of the sample, using two wavelengths to increase the efficiency of heat removal by combining excited state absorption and AS emission, and cooling of lasers by the use of selective doping of the core and cladding regions of an optical fibre, amongst others. We have begun preliminary spectroscopic studies of samples acquired through collaboration with Naval Research Laboratories, USA, and the University of Pisa to bench-mark cooling. With these materials, we will also attempt to enhance the cooling rate by a new scheme of superradiance, which we have proposed recently. Using this technique, we believe we will overcome a major shortcoming in laser cooling of solids, i.e. the restriction for using only low phonon materials, and also semiconductors for the first time, by enhancing the rate of cooling a hundred fold. In addition to a variety of rare-earth doped crystals and glasses, with this breakthrough, we will be able to explore new materials for better efficiency, such as quantum dots and nano-particles in glassy host materials. The research will have a very strong, multidisciplinary impact on the training of HQP and also commercially in Canada by allowing new devices for cooling applications, for example, for the heat removal in extremely important industry of high power LED lighting.