Cavity-enhanced laser cooling for Yb^3+-doped fluoride crystal using a low-power diode laser

Abstract

A diode laser with a power of 178 mW is used to pump a 2.2% (wt.) Yb 3 -doped YLiF 4 crystal in an optical extracavity, and a resonant cavity-enhanced laser cooling for Yb 3 -doped fluoride crystal is proposed and demonstrated. The pump laser enhancement factor so far obtained is up to 8.6 with the resonant cavity. Given that 82% of incident laser power is absorbed, the cooling efficiency is calculated as 1.08% and the temperature drop is 12.3 K/W. Accordingly, the combination of the diode laser-featuring low cost, long life, small weight, compact volume, and low power consumption-and the simple resonant cavity for laser cooling of solids is promising in some important applications in optical refrigeration of space sensors and detectors, etc.