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,traditiona...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.展开更多
基金supported by the National Key Research&Development Program of China(2023YFA1608503)National Natural Science Foundation of China(62375165 and 62122049).
文摘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.
