Demonstration of a solid-state optical cooler: An approach to cryogenic refrigeration

Abstract
We report the successful operation of an optical cooler system. This device achieved 48 °C of cooling from room temperature and a heat lift of 25 mW when it was pumped with 1.6 W of laser light. Its performance as a function of pump laser wavelength and chamber temperature agrees well with theoretical models. This device validates the physics needed for exploiting the laser cooling of solids to develop practical optical refrigerators.