Theoretical analysis on cavity-enhanced laser cooling of Er3+-doped glasses

Abstract

In recent years, Er3+ doped CdF2-CdCl2-NaF-BaF2-BaCl2-ZnF2 (CNBZN) glass has become one of the new materials in the field of laser cooling of solids. In this paper, using the theory of laser output and standing wave resonance, intracavity-and extracavity-enhanced laser cooling of Er3+-doped CNBZN glass are theoretically analyzed. Calculated results show that enhancement factor can achieve tens to hundreds of times. Moreover, two schemes are compared with each other, and the results show that for low material absorption, especially when the sample length is less than 0.3 mm, intracavity configuration has the advantage of high pumping power and high absorption. However, for high material absorption, especially when the sample length is longer than 3 mm, the extracavity configuration becomes a more efficient means for laser cooling. Finally, according to the operating wavelength and power requirements of Er3+-doped material, cavity enhancement can be realized experimentally using semiconductor diode laser.