Experimental investigation of saturation of the gain experienced by 1 nsec laser pulses in neodymium glasses

Direct measurements were made of saturation of the gain experienced by 1 nsec laser pulses in silicate (GLS1) and phosphate (GLS21) neodymium glass amplifiers. The energy density at the output reached 6 J/cm${}^2$. The measurement method employed made it possible to reduce considerably the errors resulting from small-scale self-focusing of the laser beam and from an inhomogeneous distribution of the energy density in the beam.