Surface phonon polaritons as a source of laser cooling perturbation

Abstract

The influence of a solid-state sample placed in the vicinity of a laser cooled sample is theoretically investigated. The laser cooling process is based on anti-Stokes fluorescence. The laser cooled sample is a rare-earth doped low-phonon energy solid. In this system, all samples can support surface phonon polaritons (SPhPs) in the same or different wavelength regions. Two different cases are considered. In the first case a laser cooled ytterbium-doped yttrium aluminum garnet ( Yb3+:YAG ) sample is placed in a vacuum chamber near a YAG sample, which is at room temperature. In the second case a laser cooled Yb3+:YAG sample is placed near a silicon carbide (SiC) sample, which is at room temperature. It is shown that for short distances between samples, when there is coupling between SPhPs propagating in the sample undergoing laser cooling and SPhPs propagating in the next sample, the laser cooling process can deteriorate substantially. In the opposite case the SPhPs do not influence the laser cooling process significantly even if the distance between the samples is less than the dominant wavelength of thermal radiation.