Single grating mirror intracavity stretcher design for chirped pulse regenerative amplification

We demonstrated for the first time, to the best of our knowledge a new intracavity pulse stretching design, employing a single grating-mirror based on a leaky-mode grating-waveguide design. The extremely compact and flexible layout allows for femtosecond pulses to be easily stretched up to nanosecond durations. The stretcher was implemented in a diode-pumped Yb:CALGO regenerative amplifier followed by a standard transmission grating compressor. We demonstrated sub-200 fs long pulses (stretched pulses approximate to 110 ps) with a maximum energy of 205 mu J at 20 kHz repetition rate. As a proof of the robustness and potential energy scaling of leaky-mode grating- waveguide intracavity stretcher, energies up to 700 mu J and 400 ps long pulses before compression at a lower repetition rate of 10 kHz, have been achieved. A simple model is proposed to investigate the cavity behavior in presence of induced spatial chirp.