Abstract

Laser action of transition-metal-doped zinc chalcogenide (Cr²⁺:ZnSe, Cr²⁺:ZnS) were previously demonstrated[1] in the mid infrared with a large tunability according to their broadband emission spectrum Whereas previous results were obtained with single-crystals [2], we report laser action with home-doped Cr²⁺:ZnSe polycristal materials using a diffusion method Obviously, the advantage of polycristal ZnSe as a host material is referred to its low cost , availability and the ease to grow it In our experiment, the pumping wavelength at 1 8 µm was obtained using an LiNbO₃ OPO (Optical Parametric Oscillator) pumped at 1 064 µm We tested 3 samples having different doping levels Their absorption coefficient at 1 8 µm and upper laser level lifetime are respectively 2, 4, 8 cm⁻¹ and 6, 6 6, 4 7 µs These values are smaller as compared to measured lifetime on single -crystal samples (around 8µs) because of the increase of nonradiative effects in the polycristal structure

© 2000 IEEE