Brief history and outlook of laser cooling of solids

Cooling of matter with narrowband radiation was proposed in 1929 and laser cooling of solids was demonstrated by the team of Richard Epstein at Los Alamos in 1995. Works that emerged from a collaboration between Los Alamos and the University of New Mexico under the guidance of Richard Epstein and Mansoor Sheik-Bahae laid the foundation for the vibrant new field of optical refrigeration. We will review key successes and the pivotal role Mansoor Sheik-Bahae played in these developments. With routine cryogenic cooling of payloads achieved by rare-earth doped cryocoolers, the field is facing new exciting challenges in applications, material science and fundamental limits of light-matter interactions.