High-energy, few-optical-cycle pulses at 1.5 ?m with passive carrier-envelope phase stabilization

We report on a source of ultrabroadband self-phase-stabilized near-IR pulses by difference-frequency generation of a hollow-fiber broadened supercontinuum followed by two-stage optical parametric amplification. We demonstrate energies up to 200 µJ with 15 fs pulse width, making this source suited as a driver for attosecond pulse generation.