DESIGN AND OPERATION OF A 150-W NEAR DIFFRACTION-LIMITED LASER-AMPLIFIER WITH SBS WAVE-FRONT CORRECTION

The design and operation of a Nd:glass regenerative amplifier using a stimulated Brillouin scattering (SBS) phase conjugate mirror is presented. The system can be operated at 25-30 J per pulse with a pulse width of 14 ns and a pulse repetition frequency (PRF) of 6 Hz. This results in an average output power of > 150 W with a peak power of 2 GW. The experimentally measured divergence of the amplifier output is 1.25 x the diffraction limit and it can be frequency doubled with > 80% efficiency. The detailed considerations required for this specific amplifier design are discussed as well as how these considerations apply to the design of high average power, high beam quality laser systems in general.