Water Cooled DPSS Laser Gain Modules

For QCW DPSSL gain module gain distribution, pumping efficiency and life time are three most important indices. The gain distribution has two effects on beam quality. On one hand the energy density distribution sets the distribution of the gain and the non-uniform gain distribution result in changes of intensity distribution in near field; On the other hand thermal effect in the gain medium cannot be ignored at high frequency. Uniform energy density means uniform heat density and the wave-front distortion is parabolic, which can be regarded as a lens and compensated easily. While non-uniform energy density results in high order distortion which is hard compensated for and reduces the focusing ability of the beam. In multi-pass amplifier these effects come worse.