Dependence of laser-induced breakdown field strength on pulse duration

Abstract
Field strengths at which optical damage is initiated in NaCl have been measured with a mode‐locked Nd: YAG laser with pulse durations of 15 and 300 psec. Comparison with previously reported data with a Q‐switched laser shows that the field strength required for intrinsic optical damage increases by almost one order of magnitude from 106 V/cm at 10−8 sec to over 107 V/cm at 1.5 × 10−11 sec. This is in qualitative agreement with published estimates based on the electron avalanche breakdown mechanism.