Effectiveness of passive mode locking in flashlamp-pumped lasers utilizing wide-gap solid-state media

The fluctuation model of solid-state lasers with passive mode locking and an instantaneous-response absorber is used in a study of the effectiveness of discrimination against intensity peaks generated in wide-gap active media with a finite gain relaxation time comparable with the duration of the pump pulses. It is shown that effective mode locking occurs in certain ranges of the excess of the pumping rate above the threshold and of the values of the gain saturation parameter. Changes in these ranges due to widening of the gain band suggest the need to use harder absorbers. The calculated results are in qualitative agreement with the experimental data on the increase in the effectiveness of passive mode locking in a flashlamp-pumped Al₂O₃:Ti³⁺ laser as a result of narrowing of its emission spectrum with the aid of prism selectors.