LASER-INDUCED ELECTRIC BREAKDOWN IN WATER

Dielectric breakdown induced in water by Nd:YAG laser pulses is considered experimentally and theoretically. The effect appears to be due to electron avalanche ionization. The aspects of this process considered here are the following: (i) The dependence of the breakdown probability on the laser field. At high fields, electron interaction with molecular (Raman) vibrations or with collective molecular motions occurs. (ii) Bragg scattering, which contributes to keeping the electron motion in phase with the optical field. (iii) The role of the electron mobility, which contributes to stabilizing the process. (iv) The generation of the electrons that start the avalanche in relation to different laser-pulse durations and irradiances.