Spectral broadening and post-compression of a high-repetition rate Yb-pumped OPA in the visible and ultraviolet

We demonstrate spectral broadening and post-compression of high-repetition-rate visible and near-UV pulses from a commercial Yb-pumped optical parametric amplifier (OPA). Second-harmonic pulses from the signal of a 515 nm-pumped OPA (350-500 nm) were broadened via self-phase modulation in a single gas-filled stretched hollow-core fiber to bandwidths supporting sub-30 fs durations. Post-compression using a prism compressor or, for the shortest pulses, chirped mirrors yielded durations as short as 15 fs. The source offers simultaneous tunability in wavelength, bandwidth (Fourier limits 70 fs to sub-10 fs), and pulse duration at repetition rates up to 33 kHz.