Progress in ultrafast, mid-infrared optical parametric chirped pulse amplifiers pumped at 1 µm

With diode-pumped Yb laser technology reaching maturity, average power scaling of multi-GW, few-cycle, short-wave and mid-infrared (MIR) optical parametric amplifiers (OPA’s) to the 100-W level has become a reality. Well established, commercially available oxide crystals offer a relatively straightforward solution in the 1.4-4-μm spectral range. Extension of the spectral coverage of high-power OPA’s beyond 5 μm may be enabled by novel, wide-bandgap non-oxide crystals with growth processes still under major development and optimization. Here, we present our results on the nonlinear optical properties of oxide (LiNbO₃, KTiOAsO₄) and non-oxide (LiGaS₂, BaGa₄S₇) crystals and the resulting 100-kHz, ultrafast infrared OPA’s based on these materials. The reported data provide design parameters and guidelines for high-average-power MIR OPA’s pumped by Yb lasers both below and above 5 μm.