Comparative Performance of Nd-Doped Solid-State Laser Materials

Abstract

One particular application under consideration for some of the Nd-doped materials investigated is an efficient laser pump source for Ti-doped solid-state laser hosts. For currently available Ti-doped materials, low doping results in relatively high threshold power leading to efficient operation only near the damage threshold. This is especially true for operation at the lower gain wavelengths of the Ti:sapphire tuning range. Longer pump pulse duration may alleviate the damage problem. A longerpulse-duration (>20 ns) Q-switched source constructed by using a material with gain lower than YAG (glass or YLF), operating near threshold, is therefore of particular interest. We have recently constructed a Nd:YLF acousto-optically Q-switched oscillator/amplifier which produces 150 mJ in a 100-ns-duration pulse with TEMoo-mode beam quality. This beam at 1.047 μm is frequency doubled in KTP, yielding 75 mJ for pumping Ti-doped laser materials. Other candidate materials for this application are Nd:BEL and Nd:glass, both of which are currently under consideration as alternatives to Nd:YLF. The increasing interest in tunable solid-state laser materials has underscored the need to identify optimal pump sources.