High power, dual SWIR-MIR OPCPA source for high-order harmonics generation

High-harmonic generation (HHG) spectroscopy enables the observation of fundamental ultrafast phenomena in nature. Recent advances in laser technology have led to the development of wavelength tunable ultrashort light sources, allowing the study of a wide variety of systems-from complex molecules to condensed matter. However, achieving broad control in key laser parameters-such as wavelength, pulse duration, and peak intensity-remains a significant challenge. We present an advanced, optical parametric chirped pulse amplifier (OPCPA) source, pumped by a single Yb:YAG laser at 50 kHz, which generates simultaneous and fully independent outputs in both the short-wave infrared (SWIR) and mid-infrared (MIR). In the SWIR, the output is optimized for two distinct wavelengths, producing pulses with a peak power of up to 17 GW centred at 2.1 µm (350 µJ, 21 fs) or 10 GW centred at 1.75 µm (420 µJ, 40 fs). In the MIR, the OPCPA delivers up to 57 µJ, with pulse durations as short as 48 fs and tunability from 2.5 to 7.6 µm. We demonstrate the system's versatility by tailoring the laser parameters to optimize high-harmonic generation across a broad range of band gap energies in solid-state materials. In the SWIR, XUV measurements are performed at high repetition rates, overcoming the typical challenges of operating in high-vacuum environments under such conditions. In the MIR, we demonstrate that temporal pulse shaping can optimize harmonic emission while simultaneously suppressing deleterious nonlinear effects induced by the strong driving field. With its unique combination of wavelength tunability and peak power at high repetition rates, this OPCPA opens up exciting possibilities for expanding the boundaries of strong-field physics and attosecond science.