Diode side-pumped, high efficiency Nd:YVO{sub}4 laser and improvement in beam quality

摘要

Diode pumped solid state laser are developing at a very fast rate. At the same time, materials that in some aspects have better characteristics than Nd:YAG are on the market such as Nd:YVO{sub}4, Nd:GdVO{sub}4, Yb:YAG and others. Within the existing variety of geometries and gain materials there is one combination that is particularly interesting because of its reduced complexity and high efficiency: the edge-pumped slab-laser using grazing-incidence geometry and a gain media with a very high pump absorption cross-section. Previously, we demonstrated high efficiency in multimode with a side-pumped Nd:YVO{sub}4 laser using a grazing incidence geometry [1]. In this work, we describe a compact cavity with high slope efficiency with one pass inside the gain media and a significant improvement in beam quality with a novel cavity with only three mirrors and a second pass inside the gain media. Moreover, this cavity uses joint stability zones, giving therefore almost constant beam parameters throughout a wide range of pump powers. The laser crystal is a Nd:YVO{sub}4 with 1.1 at.% neodymium doping with dimensions 22×5×2 mm{sup}3. The end faces (5×2 mm{sup}2) have AR coating for the 1064 nm laser. The crystal is pumped on the 22×5mm{sup}2 edge face, which has AR coating for the 808 nm wavelength. The pump source is a 48 watts TM-polarized diode bar operating at 808 nm with the TM polarization parallel to the c-axis of the crystal.