Pulse contrast stands as a crucial performance metric for intense lasers

and its accurate characterization is indispensable for improving laser system and evaluating strong-field physics experiments. However

traditional methods for ultrahigh-dynamic-range pulse-contrast characterization based on third-order cross-correlation necessitate single-photon detection sensitivity

rendering them susceptible to shot noise and resulting in significant fluctuations in measuring results between shots. In this study

we demonstrate that the impact of shot noise can be considerably reduced by employing an optical parametric amplification correlator (OPAC). The OPAC offers photon gain that counteracts the photon loss incurred during nonlinear conversion and along the propagation path while simultaneously generating parametric super-fluorescence to enhance the number of photons that ultimately reach the detector. These combined effects effectively mitigate shot noise even when the pulse under test contains only a few photons. Consequently

the OPAC facilitates reliable

ultrahigh-dynamic-range

single-shot characterization on pulse contrast of intense lasers

marked by improved shot-to-shot reproducibility.