Bleaching of ZnTe:Li crystals by green laser radiation

Bleaching close to the fundamental absorption edge was observed in lithium-doped zinc telluride at 77°K. A Raduga Model dye laser, emitting at λ = 531 nm, was used and an increase in the transmission by a factor exceeding 300 was recorded for samples 0.06 cm thick. In the case of undoped crystals there was no absorption saturation right up to powers which caused surface damage. The bleaching effect was attributed to optical transitions from the acceptor level of lithium to the conduction band.