We experimentally demonstrate amplitude and phase shaping of femtosecond mid-infrared pulses in a range centered about 14 μm. Single pulses with a tailored optical phase and phase-locked double pulses are generated by phase-matched difference-frequency mixing in a GaSe crystal of near-infrared pulses shaped with a liquid-crystal modulator. The electric field transients are directly measured by free-space electro-optic sampling, yielding pulse durations of 200-300 fs. Our data are in good agreement with a model that describes phase-matched optical rectification.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics