Powerful sub-100-fs pulses broadly tunable in the visible from a blue-pumped parametric generator and amplifier

By combining a low-gain single-pass collinear amplifier with a high-gain noncollinear seeder, in which the group velocities are self-matched, we demonstrate highly efficient parametric conversion of frequency-doubled Ti:sapphire pulses of hundreds-microjoule energy. With \u3b2-barium borate in both seeder and amplifier, bandwidth-limited signal pulses tunable between 0.46 and 0.66 \u3bcm are obtained at a 1-kHz-repetition rate, with duration as short as 78 fs and energy as much as 17 \u3bcJ in the visible