LAUSR

Cr2+:ZnSe polycrystalline active elements in the form of disks with one and two inner doped layers were fabricated by using solid-state diffusion bonding (SSDB) with subsequent hot isostatic pressing. A comparison of the generation properties of active elements with the same absorption and various profiles of internal doping was made using a scheme with a semi-confocal cavity and CW thulium fiber laser pumping. All test samples showed high thermal and optical resistance at a pump power density of up to 50 kW cm−2 in room-temperature experiments that indicates the promise of using SSDB technology in high-power mid-IR lasers. The samples with two layers of internal doping demonstrated 30% higher lasing slope efficiency, than samples with one doped layer. This difference is explained by more uniform heating of the active element which was caused by increasing the volume of the sample involved in the absorption of pumping radiation.