Abstract

We describe results of experiments in a crossed-beam transient Raman amplifier that examine the spatial quality of the amplified Stokes beam, beam combining properties, and effects related to replication of the crossing pump beams. The experimental measurements were made using 40-ps pulses produced by a mode-locked Nd:YAG laser doubled to 532 nm. The seed Stokes at 683 nm was produced in a self-generator cell filled with hydrogen gas at 25 atm. Both the seed Stokes and the pump beam were spatially filtered before being combined with a variable delay and collimated to have confocal parameters in excess of the 1-m length of the amplifier cell. The pump was split into two beams and crossed in the center of the amplifier cell. An intensified camera was used to record the near-field spatial profiles of the amplified Stokes. These data were then Fourier transformed and compared with measured far-field profiles to indicate the beam quality of the amplified Stokes.

© 1988 Optical Society of America