Optical parametric amplifier pulse cleaning driven by aperiodic frequency converter

We demonstrate temporal shape improvement of a short laser pulse using chirped aperiodic nonlinear frequency converter within an optical parametric amplifier. The aperiodic converter generated walk-off free high spatial quality pulse with similar to 40% efficiency second harmonic while preserving the pump bandwidth. A <300 fs idler pulse was generated, with similar to 10 nm central wavelength tunability around 1053 nm by pump generation and phase matching control. A pronounced contrast pedestal suppression of up to 40 dB was observed within a few picoseconds range around the peak. Such pedestal suppression has good scalability potential to high energies.