Femtosecond laser-induced breakdown in water: Time-resolved shadow imagingand two-color interferometric imaging

Time-resolved shadow imaging and novel two-color interferometric imaging ha ve been developed for the investigation of optical breakdown induced in wat er by 100 fs laser pulses with a spatial resolution better than 5 mu m. Wit h a femtosecond time resolution, we clearly identified induced-plasma and f ilamentation formations, as well as the shock wave expansion. Using the two -color interferometric imaging technique together with a conventional Mach- Zehnder interferometer, we investigated the phase shift of the interference fringes produced in water by the femtosecond optical breakdown. For differ ent pump energies, at 40 ns after the breakdown, we estimated the water tem perature between 30 and 60 degrees C and the water pressure between 10 and 40 MPa at the shock wave front.