Spectroscopic Investigation of Yb-doped Silica Glass for Solid-State Optical Refrigeration

TL;DR

This study explores the potential of Yb-doped silica glass for optical refrigeration by analyzing its spectroscopic properties, suggesting it could be cooled effectively through anti-Stokes fluorescence with high efficiency.

Contribution

It demonstrates that Yb-doped silica glass can achieve near-unity internal quantum efficiency, enabling potential optical cooling based on spectroscopic measurements.

Findings

High-purity Yb-doped silica can have low non-radiative decay rates.

Spectral measurements estimate achievable cooling temperatures.

Potential for solid-state optical refrigeration using silica glass.

Abstract

We have argued that a high-purity Yb-doped silica glass can potentially be cooled via anti-Stokes fluorescence optical refrigeration. This conclusion is reached by showing, using reasonable assumptions for the host material properties, that the non-radiative decay rate of Yb ions can be made substantially smaller than the radiative decay rate. Therefore, an internal quantum efficiency of near unity can be obtained. Using spectral measurements of the fluorescence emission from a Yb-doped silica optical fiber at different temperatures, we estimate the minimum achievable temperature in Yb-doped silica glass for different values of internal quantum efficiency.