THERMAL-DEFOCUSING SCATTERING OPTICAL LIMITER

Operation of an f/5 thermal-defocusing/scattering optical limiter is d escribed. Thermal-defocusing limiting of 6-ns-duration, 532-nm laser p ulses occurs by use of the broadband-absorbing dye Nigrosin dissolved in carbon disulfide. Additional limiting due to thermally induced scat tering occurs at high incident fluences (above a threshold fluence) wh en either surface-roughened BASF-1 glass windows are in contact with t he dye solution or microscopic glass fibers are added to the liquid ce ll. Limiter figures of merit are improved by factors of 2 and 4, respe ctively, over that of a purely thermal-defocusing limiter.