Stable high-contrast femtosecond laser pulse source

A stable high-contrast femtosecond laser pulse source comprises a pumping source, a spectrum broadening system, a laser pulse purification system, a parametric amplification system and a dispersion compensation system. The pulse is subjected to shaping filtering through hollow optical fibers, to pulse purification through a cross polarized wave generating device, to optical parametric amplification and pulse compression, finally, the output of the high-contrast femtosecond laser pulse is achieved. According to the high-contrast femtosecond laser pulse source, not only the problem of the serious damage to crystals due to cross polarized waves under large energy is avoided, but also the stable output of the high-contrast femtosecond laser pulse during long working time is achieved. The stable high-contrast femtosecond laser pulse source is widely applicable to attosecond pulse generation and the like.