Room-temperature Fe2+ : ZnS single crystal laser pumped by an electric-discharge HF laser

A room-temperature laser based on a Fe²⁺ : ZnS single crystal has been studied. The crystal was pumped by a nonchain electric-discharge HF laser with a light pulse FWHM of ~140 ns. The pump spot diameter on the crystal surface (d ) varied from 3.9 to 11.6 mm. The slope efficiency at these values of d was 37% – 39%, respectively. The maximum laser energy was 380 mJ (at d = 11.6 mm) with the total efficiency with respect to the absorbed pump energy of ~19%. A further increase in the laser energy was not achieved because the crystal was destroyed at an incident pump energy and power of 3.4 J and ~24 MW, respectively. The damaged region has a form of a long narrow channel shifted from the entrance surface inside the active element.