High-power TEM 00 -mode operation of diode-pumped solid state lasers

Abstract

The performance of end-pumped YAG and YVO<SUB>4</SUB> lasers in fundamental mode operation (M<SUP>2</SUP> < 1.1) is reviewed and the physical limits of TEM<SUB>00</SUB> output power is discussed. By using special resonator configurations, end-pumped lasers can be designed to provide high-power, excellent beam quality, and high-efficiency in spite of the large phase distortions commensurate with the strong aberrated thermal focusing. A 35 W infrared Nd:YVO<SUB>4</SUB> laser was developed with a quantum efficiency of 94%, defined as a percentage of 1064 nm photons generated per quantity of absorbed 809 nm pump photon. A Q-switched end-pumped Nd:YAG laser provides an average output power greater 15 W in a polarized TEM<SUB>00</SUB> mode with 29% optical efficiency at 1064 nm. External frequency doubling and tripling of this laser resulted in maximum output powers of 8.8 W and 4.2 W, respectively.