Studies On The Measurement Of The Femtosecond Laser Pulse

This dissertation presents the measure techniques of the femtosecond oscillator andamplifier. On the basis of the original measure system in the lab, the influence of theoptical components on measurement precise is optimized. Therefore, the newlydesigned and constructed instruments run more stably, easily and precisely. The maincontents of this thesis are listed below:1. The principles of second order autocorrelation measurement of the width of the femtosecond pulses are described. An interfere autocorrelation used in the oscillator stage as well as a single shot autocorrelation in amplifier stage are design and constructed.2. The bandwidth and efficiency of the second harmonic generation of femtosecond pulses are analyzed. The group velocity mismatch and second harmonic generation filter in the second harmonic generation are discussed. Autocorrelation measurement precision reduction, which due to the group velocity mismatch and second harmonic generation filter are validated by the experiments.3. .The wave front distortion caused by the beam expander is analyzed and a suggestion is offered to reduce the influence. The electric field distribution behind the telescope is calculated. The variation of the measured width of the femtosecond lasers after passing though the telescope is discussed.