| 摘要 |
This invention relates to ultrafast lasers for obtaining femtosecond light pulses with durations less than 100fs and energies up to one hundred millijoules. The method comprises at least two optical parametric amplification (OPA) stages. Optically synchronized seed and pump pulses are originated from a single primary laser source emitting pulses of 1-3 ps. Formation of a first seed radiation comprises pulse stretching and spectral broadening up to 10nm to 20nm of bandwidth, while formation of a first pump radiation comprises amplification in a narrowband (<1nm) quantum amplifier followed by second harmonic generation. Formation of a second seed radiation comprises pulse compression and white light radiation generation, while formation of a second pump radiation comprises separation of a part of signal wave radiation, amplified in the first OPA stage, pulse compression and second harmonic generation. In other embodiment a third OPA stages is provided, wherein formation of a third seed radiation comprises pulse stretching, while a third pump radiation is formed in the same way as first pump radiation. Femtosecond output pulses are obtained by compressing pulses of signal wave radiation, amplified in the final of OPA stages, down to duration of 5fs to 100fs. |
