Room-temperature lasing on Fe2+:ZnSe with meniscus inner doped layer fabricated by solid-state diffusion bonding

Abstract

An Fe2+:ZnSe laser on a polycrystalline active element with an inner doped layer in the form of a meniscus operating at room temperature was investigated. The active element was manufactured using the solid-state diffusion bonding (SSDB) technique. The billets, in the form of plano-concave and plano-convex ZnSe lenses with a radius of curvature of 200 mm, were subjected to diffusion bonding. Before bonding, zinc selenide was doped with Fe2+ ions by diffusion through spherical lens surfaces by the process of hot isostatic pressing (HIP). After the SSDB procedure, the prepared sample was subjected to an additional HIP treatment. An Fe2+:ZnSe polycrystal was pumped by an electric-discharge hydrogen fluoride (HF) laser. The use of the active element with an inner doped layer in the form of the meniscus permitted an increase in the pump spot diameter, at which there was not yet any reduction in laser output energy associated with the development of transverse parasitic oscillation. This increase was ~19% (compared to samples with a single flat doped layer). The output energy of 480 mJ was achieved at a total efficiency (with respect to absorbed energy) of 38% on the 20 mm diameter Fe2+:ZnSe sample with the meniscus inner doped layer.