Tm:fiber laser in-band pumping cryogenically-cooled Ho:YAG laser

Abstract

Cryogenically-cooled diode-pumped lasers have received significant interest in recent years for their demonstrated orders of magnitude improvement in output radiance using simple laser resonator configurations. Here we present a technique that offers the potential for a further order of magnitude improvement utilising the in-band-pumping hybrid-laser architecture to excite cryogenically-cooled bulk gain media. Preliminary results will be discussed, for a narrow linewidth Tm:fiber MOPA system operating in the 100W regime, pumping a cryogenically cooled Ho:YAG gain element, and employing a simple cavity configuration. Low quantum defect operation and power-scaling potential will be discussed