Optical Cooling in Multi-Level Systems

摘要

A theoretical model for optical cooling is developed, which yields the overall efficiency of a single end-pumped cooling system. This model includes the effects of background absorption and pump saturation, while in multi-level systems, the model accounts for the important energy transfer processes. Two-level efficiency is evaluated for the case of Yb:YAG and compared with a hypothetical three-level material with identical spectral properties. This model is readily modified to include more levels and different materials.