| Presently, the laser pulse from the high power ultrashort laser system is several femtoseconds in duration, TW(or PW) level in peak power, 1020 W/cm2( or 1021 W/cm2) in focusing power density, according electric field is much stronger than coulomb field in atoms. Such pulsewidth and peak power introduces extreme physical conditions such as high temporal resolving power, strong electromagnetic field and high pressure. And these introduced a comprehensive and profound revolution in fundamental and technology science. Out of question, the chirp pulse amplification technology that generate ultrashort and ultrahigh laser pulse has become a focus in research field. Fortunately, the project "the research on shorter than 30fs, terawatt level's laser system "we undertake is about CPA system. This paper reported our main research, it includes:1. This paper summarizes the development, application and trend of the CPA system, especially introduces the essential principle and experiment structure.2. The main part and key technique of the CPA system is study: the generation of the femtosecond laser pulse is study, the modulation and maintenance of the Ti:S laser is learned; the types of the measurement for ultrashort laser pulse is generalized and the interferometric autocorrelation is expatiated; the varieties of the stretchers is sum up and aberration-free stretcher is calculated and optimized to improve the stretching ratio; The pulse selection is analyzed and a single pulse can be selected successful from the pulse train at a repetition rate of 82MHz; The kinds of the amplifier in CPA system is gathered up, the eight-pass pre-amplifier and a good many effects in it is investigated. Finally, the second, third and fourth-order dispersions in CPA system is analyzed systemicly, and the according means for dispersion compensation is worked out.
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