Spatiotemporal couplings through a nonlinear phase in broadband optical parametric amplification

Optical parametric chirped-pulse amplification (OPCPA) is prone to undesired spatiotemporal couplings. This Letter studies a family ofOPCPAcouplings resulting fromthe non-linear phase shift induced by frequency-dependent phase mismatch. These OPCPA couplings manifest as pulse-front deformation, transversely varying pulse duration, and spectrally varying wavefront curvature, which are directly linked with the phase-mismatch dispersion terms. The numerical study in this Letter also reveals that the focused signal intensity severely degrades with increasing signal bandwidth and pumpdepletion. (C) 2021 Optical Society of America

Automated summary

OPCPA is susceptible to undesired spatiotemporal couplings caused by nonlinear phase shifts from frequency-dependent phase mismatch. These couplings result in pulse-front deformation, transversely varying pulse duration, and spectrally varying wavefront curvature, directly related to phase-mismatch dispersion terms. Numerical study shows that focused signal intensity significantly decreases with increasing signal bandwidth and pump depletion.