Large-aperture neodymium phosphate glass rod amplifiers for high-brightness lasers

An investigation was made of the amplification and thermooptic parameters of amplifiers utilizing an improved version of neodymium phosphate glass rods 85 and 100 mm in diameter. A study was made of the influence of the number of flashlamps and of the duration of the pump pulses, of the nature of the illumination enclosure, and of the neodymium ion concentration on the gain and its distribution over the cross section of an active element, as well as on the amplifier efficiency. The gain was 0.068 and 0.05 cm^–1 for the two rod diameters, respectively. The use of these amplifiers in the Progress laser fusion facility made it possible to increase considerably the energy and brightness of the output radiation.