OSE Faculty Member, Dr. Alexander R. Albrecht shares a paper on Demonstration of diode-pumped optical refrigeration to cryogenic temperature.

Departmental News

Dr. Alexander R. Albrecht

Posted: February 1, 2023

Abstract:

We cooled a 10% Yb:YLF crystal to temperatures of approximately 130 K using a fiber-coupled laser diode module emitting at 1020 nm. Previous approaches to optical refrigeration typically relied on high-power fiber lasers and intricate multi-pass schemes to reach cryogenic temperatures. In the current experiments a combination of dielectric mirrors deposited onto the sample and total internal reflection confined the laser light inside the crystal. The divergent beams of laser diodes produce relatively low average intensity inside the crystal, mitigating nonlinearities like absorption saturation and lasing. We have designed a full diode-pumped cryo-cooler with a coldfinger to cool arbitrary loads.

Authors: Alexander R. Albrecht, Jackson L. Kock, Seth D. Melgaard, Richard I. Epstein, and Mansoor Sheik-Bahae.

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