Enhancement of pump efficiency of thin disk lasers by compensation of directional image extension on pumping spot

摘要

The effect of directional image extension on the total pumping spot in thin disk lasers is reviewed. Three modified pumping setups that can compensate this effect and improve the absorption pumping area are presented, and the efficiency, advantages, and disadvantages of each modified configuration are discussed. Numerical comparison between absorption intensity profiles confirms an increment of maximum pump absorption density at the central region of the pumping area with respect to normal setup. Experimental investigation for the last modified pumping arrangement is in good agreement with simulation results. Measuring laser power output with a similar simple l-shaped resonator shows an enhancement of slope efficiency up to 2.5% together with a lower laser threshold for our modified setup.