COMPACT ND-YAG AND ND-YVO4 AMPLIFIERS END-PUMPED BY A HIGH-BRIGHTNESSSTACKED ARRAY

We analyze both theoretically and experimentally the performances of c ompact laser amplifiers longitudinally pumped by a high-brightness sta cked array. Results are given for Nd:YAG and Nd:YVO4 as the active med ia. A model of amplification which takes into account the particular p umping configuration is presented to fit the experimental results. Wit h less than 5-mm-long crystals, single-pass small-signal gain-length p roducts of similar to 1.6 on a 1.5 mm x 1.5 mm aperture are demonstrat ed with optical-to-optical extraction efficiency of similar to 25%. Th e influences of the amplified spontaneous emission, crystal orientatio ns, pump beam characteristics, and standing wave grating on the gain a re also analyzed.