Laser-induced breakdown in silver halide crystals and polycrystalline fibers

The maximal laser power transmitted through polycrystalline silver halide fibers is limited by their IR absorption and optical strength. The mechanisms of the IR absorption and laser-induced breakdown (LIB) thresholds P _c in AgCl _xBr _1-x crystals and polycrystalline fibers were studied. Investigations, including mechanical treatments, heat treatments, and luminescence properties were performed to clarify the reason for the IR absorption and LIB in silver halide crystals and fibers. From these experiments we concluded that one of the reasons for LIB may be the avalanche of electrons in the conduction band of the crystal. These seed electrons are produced by the IR absorption of the cation vacancies in these crystals. A simple annealing procedure for reduction of the IR absorption of fibers is proposed.