Performance of a liquid nitrogen cooled CW Tm Ho:YLF laser

A liquid-nitrogen-cooled Tm, Ho:YLF laser is constructed with a 10-mm-long Tm(6%) and Ho(0.5%) codoped yttrium lithium fluoride crystal pumped by a laser diode operating at 792 nm. The laser output power is improved by cooling the Tm, Ho:YLF crystal from 300 to 77 K. When the crystal is kept at 77 K