Design of an ultrashort-pulse multipass amplifier and investigations of femtosecond optical breakdown

Date of Completion

January 1999


Physics, Optics




Development, diagnosis and applications of an ultrafast laser system are presented in this dissertation. This unique Ti:Sapphire laser system is capable of providing 25 fs millijoule-level transform-limited pulses. A novel laser diagnosis system, called dispersion free TG FROG, is designed to completely characterize these ultrashort pulses. The dynamics of femtosecond optical breakdown, was investigated for the first time using a new pump-probe technique with this laser system. The experimental results indicate that the plasma energy decay during the femtosecond optical breakdown is an ultrafast process (∼100 fs). This new discovery changes the whole picture of the breakdown process. It is important to both basic physics as well as industrial applications. ^