Laser cooling of solids has great potential to achieve an all-solid-state optical cryo-cooler. The advantages of compactness, no vibrations, no moving parts or fluids, and high reliability have motivated intensive research. Increasing the pump power absorption is essential to reach lower temperatures. Here, using a high power broadly tunable InGaAs/GaAs vertical external-cavity surface-emitting laser (VECSEL) we demonstrate how we have increased the pump power absorption in an intra-cavity geometry cooling a 10% Yb:YLF crystal. We also discuss the progress, advantages, and challenges of laser cooling inside a VECSEL cavity, including the VECSEL active region design, cavity design, and cooling sample choice for optimal cooling. A novel method to increase the absorption of the pump power in the crystal has also been proposed.

Date Published: 10 March 2015
PDF: 8 pages
Proc. SPIE 9380, Laser Refrigeration of Solids VIII, 938003 (10 March 2015); doi: 10.1117/12.2080343

Published in SPIE Proceedings Vol. 9380:
Laser Refrigeration of Solids VIII
Richard I. Epstein; Denis V. Seletskiy; Mansoor Sheik-Bahae, Editor(s)