Transient thermal-lensing effects on the performance of repetitively pulsed solid-state lasers

A computational model was developed to predict solid-state laser performance in the start-up transient regime of a repetitive pulse operation. Laser output in this regime is sensitive to the interaction of rate-equation, thermal-transport, and beam-propagation effects. A high-repetition-rate operation produces pulse trains that decay at a rate determined by the competition between energy deposition in the rod and surface cooling. Selected pulses in a train turn on and off as the repetition rate is increased because of the varying residual population inversion between pulses.