Repetitively pulsed Nd-glass slab lasers

The possibility of obtaining high laser output energies at a 1.32-μm wavelength using thin LiNdLa phosphate glass slabs with a high Nd³⁺ concentration is discussed. In the experiments, 3×14×125-mm slabs were prepared from LiNdLa phosphate glass with a Nd-concentration of 1.2×10²¹ cm^-3. The facets of the slabs were not antireflection-coated. They were tested in a silver-coated quartz tube reflector of 25-mm diameter and pumped by 450-μs pulses from a flash lamp with a 120-mm arc length. In this construction the light, which passes through the slab, returns to it after reflection from the tube surface. Most of the radiation falls on the wider side of the slab at large angles of incidence, thus maximizing its path inside the slab. The quartz reflector was water cooled. The 150-mm laser resonator was formed by two flat mirrors. At 1.32-μm lasing wavelength an output mirror of r=95% reflectivity was used with less than 10% reflectivity at 1.32 μm