Investigation of Fe : ZnSe laser in pulsed and repetitively pulsed regimes

Abstract

The characteristics of a Fe : ZnSe laser pumped by a single-pulse free-running Er : YAG laser and a repetitively pulsed HF laser are presented. An output energy of is achieved in the case of liquid-nitrogen cooling of the : ZnSe active laser element longitudinally pumped by an Er:YAG laser with a pulse duration of and an energy up to . The laser efficiency with respect to the absorbed energy is 47%. The output pulse energy at room temperature is . The decrease in the output energy is explained by a strong temperature dependence of the upper laser level lifetime and by pulsed heating of the active element. The temperature dependence of the upper laser level lifetime is used to determine the pump parameters needed to achieve high pulse energies at room temperature. Stable repetitively-pulsed operation of the : ZnSe laser at room temperature with an average power of and a maximum pulse energy of is achieved upon pumping by a train of HF laser pulses with a repetition rate of .