Thermal lenses in glass active elements of pulse-periodic lasers

An analysis was made of the influence of thermooptic characteristics P, Q, and θ = dP/dt of laser glasses on the power of a thermal lens induced in an active element of a pulse-periodic laser. The powers of these thermal lenses and their temperature dependences were determined for several athermal phosphate glasses. A new method was developed for the determination of P, Q, and θ from the aberration parameters of a thermal lens. The values of P, Q, and θ found by this method for the investigated glasses were compared with the published values. The temperature dependences of the output energy and divergence were determined. It was found that the glasses with the lowest value of θ were characterized by the weakest temperature dependences of these characteristics.