BREAKDOWN THRESHOLD AND PLASMA FORMATION IN FEMTOSECOND LASER-SOLID INTERACTION

Combining femtosecond pump-probe techniques with optical microscopy, w e have studied laser-induced optical breakdown in optically transparen t solids with high temporal and spatial resolution. The threshold of p lasma formation has been determined from measurements of the changes o f the optical reflectivity associated with the developing plasma. It i s shown that plasma generation occurs at the surface. We have observed a remarkable resistance to optical breakdown and material damage in t he interaction of femtosecond laser pulses with bulk optical materials . (C) 1996 Optical Society of America