Doping profile influence on a polycrystalline Cr2+:ZnSe laser efficiency

Cr2+:ZnSe polycrystalline active elements were fabricated, with different distribution profiles of Cr ions concentration over their thicknesses and an equal absorption at a pump wavelength of 1.9 µm. The lasing characteristics of the obtained samples in short cavity schemes were determined, using a CW Tm3+-doped fiber laser and a Tm3+:YLF pulsed laser as the sources of pumping. There was found to be a correlation between the generation slope efficiency and the shape of the concentration profile. It was determined that bilateral doping samples achieved better laser performance. The maximum values of the slope efficiencies with respect to the absorbed power were η =73% in the pulse-periodic mode, and η = 37% in the continuous-wave mode.