High-energy pulse compression using phase shifts produced by the cascade quadriatic nonlinearity

摘要

We report an optical pulse-compression technique based on quadratic nonlinear media. Negative nonlinear phase shifts are generated via phase-mismatched second-harmonic generation, and the phase-modulated pulses are then compressed by propagation through materials with normal dispersion. Millijoule-energy pulses from a Ti:sapphire amplifier are compressed from 120 to 30 fs, and calculations indicate that compression ratios10 are realistically achievable using this approach with optimal materials. The insertion loss of the compressor can be less than 10% of the pulse energy, and scaling to higher pulse energies will be straightforward.