Thermoelectrically cooled, repetitively pulsed Fe : ZnSe laser

We report the investigation of a repetitively pulsed laser based on a Fe : ZnSe crystal, cooled to a temperature of 195 K by two thermoelectric modules with a maximum cooling power of 34 W. Two pulsed synchronised Er : YAG lasers, operating in the freelasing regime, are used for pumping. It is shown that the average laser power in a series of short pulses may exceed 20 W. An average power of 3.1 W is attained in the stationary temperature regime. The lasing spectrum is centred at a wavelength of 4.38 μm, and the total divergence angle is 5 mrad.