Beam combination in Raman amplifiers

The energy capability of pulsed laser systems can be extended by using a Raman amplifier to combine the energy of several pump beams into a single output. Energy is extracted from the pump beam(s) by the amplification of a Raman shifted Stokes seed pulse. Beam combination has particular application to neodymium based visible lasers in which the pulse energy can be limited by the damage threshold of the second harmonic generating crystal. In this paper the properties of a Raman amplifier pumped by a frequency doubled Nd:YAG laser have been investigated experimentally. >