Room temperature Fe~(2+):ZnS laser

摘要

Characteristics of a laser on polycrystalline ZnS:Fe~(2+) subjected from two sides to diffuse doping at room temperature are investigated. The sample was pumped by a non-chain electrodischarge HF laser with the radiation pulse FWHM duration of ～140 ns. The diameter of pumping radiation spot on the surface of crystal was 3.8 mm. Further increase of the size of pumping spot was limited by parasitic generation arising due to a high concentration of Fe ions in the near-surface layer of sample at a relatively small depth of doping (short length of active medium). The output energy of ZnS:Fe~(2+) laser was 25.5 mJ at the slope efficiency with respect to the energy absorbed in the crystal of 20%. Characteristics of lasers on polycrystalline ZnS:Fe~(2+) and ZnSe:Fe~(2+) have been compared in equal pumping conditions. The slope efficiency of ZnSe:Fe~(2+) laser was 34%. At equal pumping energy absorbed in the samples, the duration of ZnSe:Fe~(2+) laser radiation pulse was longer than that of ZnS:Fe~(2+) laser. Possibilities of increasing the efficiency of ZnS:Fe~(2+) laser operation at room temperature by improving the technology of sample manufacturing and reducing the duration of pumping pulse are discussed.