Tunable femtosecond pulses in the near-ultraviolet from ultrabroadband parametric amplification

Using an ultrabroadband amplification technique in a β-barium borate noncollinear optical parametric amplifier, pumped by the third harmonic of a 1 kHz Ti:sapphire laser, we generate tunable femtosecond pulses in the range of 335–480 nm with energies of a few hundred nJ. The developed setup is an amplification source with a bandwidth of more than 200 THz and provides femtosecond pulses in the near-ultraviolet spectral range using coherent amplification. Parts of the amplified white-light continuum spectrum were compressed to 24–35 fs using a prism pair. Further improvements could make it possible to generate tunable ultraviolet pulses as short as 4–5 fs.