High-power neodymium phosphate glass telescopic amplifier of single-pulse radiation

An experimental investigation was made of a five-pass telescopic amplifier with a phototropic switch in its resonator. The use of GLS-21 phosphate glass made it possible to increase the energy of single-pulse radiation to 90 J and the energy efficiency was 0.5%. The angular divergence of the radiation measured at 0.7 of the maximum energy level was 0.18 mrad and it was limited by optical inhomogeneities of the active element in its "cold" state. An analysis was made of possible configurations of a telescopic amplifier with a switch in its resonator. A simple model was developed for calculating the energy characteristics of such amplifiers on the basis of the available experimental results.