A two-pass three-channel slab amplifier

A highly efficient slab amplifier has been designed. It has an aperture of 100 mm. The laser beam passes through the amplifier via three channels and then goes through it for the second time. Under typical conditions, we have obtained a gain of tenfold, an output intensity of 10
¹¹
W [1], and an efficiency of 0.1 percent. By means of astigmatism compensation, the statical beam divergence after passing through 72 surfaces has been improved to 60 μrad, and the dynamic beam divergence to 0.2 mrad.