Laser parameters of a Fe:ZnSe crystal in the 85-255-K temperature range

The temperature dependence of the efficiency of a laser based on a Fe:ZnSe crystal grown from the vapour phase by the free-growth method is studied in the 85-255-K temperature range. As the temperature was increased, the slope efficiency of the laser with respect to absorbed energy decreased from 43% (at 85 K) down to 9% (at 255 K) and its emission spectrum shifted from 4.0 to 4.17 mu m. Lasing was obtained in a Fe2+:ZnSe crystal cooled with a thermoelectric module down to similar to 220 K. In this case, the slope efficiency of the laser with respect to absorbed energy was 30%. The output energy of the thermoelectrically cooled laser was 142 mJ for the slope efficiency with respect to the incident pump energy equal to 21%.