Nf. Andreev et al., 4-PASS YAG-ND LASER SYSTEM WITH COMPENSAT ION OF ABERRATION AND POLARIZATION DISTORTIONS OF THE WAVE-FRONT, Kvantovaa elektronika, 23(1), 1996, pp. 21-24
A four-pass laser with two amplifiers was constructed. It operates at
a repetition frequency of 25 Hz and generates pulses of 5-7 ns duratio
n and 2 J energy with a divergence close to the diffraction limit.