Solid-state laser with a composite active element and diffraction-limit divergence

An investigation was made of a two-pass laser amplifier with a wavefront-reversing cell. Composite active elements were constructed from small-diameter rods made of neodymium phosphate glass or of YAG:Nd³⁺ crystals. Such active elements ensured a high output radiation energy in the form of single pulses emitted at relatively high repetition frequencies. The divergence of the output radiation, governed by diffraction on a stop, was equivalent to the aperture of the composite active element.