Design and optimization of a high-energy optical parametric amplifier for broadband, spectrally incoherent pulses

Abstract

Spectrally incoherent laser pulses with sufficiently large fractional bandwidth are in demand for the mitigation of laser–plasma instabilities occurring in high-energy laser–target interactions. Here, we modeled, implemented, and optimized a dual-stage high-energy optical parametric amplifier for broadband, spectrally incoherent pulses in the near-infrared. The amplifier delivers close to 400 mJ of signal energy through noncollinear parametric interaction of 100-nJ-scale broadband, spectrally incoherent seed pulses near 1053 nm with a narrowband high-energy pump operating at 526.5 nm. Mitigation strategies for high-frequency spatial modulations in the amplified signal caused by index inhomogeneities in the Nd:YLF rods of the pump laser are explored and discussed in detail.