Light–matter interactions driven by ultrahigh-intensity lasers have great potential to uncover the physics associated with quantum electrodynamics (QED) processes occurring in neutron stars and black holes. The Compton scattering between an ultra-relativistic electron beam and an intense laser can reveal a new interaction regime, known as strong-field QED. Here we present an experimental demonstration of nonlinear Compton scattering in a strong laser field, in which a laser-accelerated multi-gigaelectronvolt electron scatters off hundreds of laser photons and converts them into a single gamma-ray photon with several-hundred-megaelectronvolt energy. Along with particle-in-cell (PIC)-QED simulations and analytical calculations, our experimental measurement of gamma-ray spectra verifies the occurrence of Compton scattering in the strongly nonlinear regime, paving the road to examine nonlinear Breit–Wheeler pair production and QED cascades.

由超高强度激光器驱动的光-物质相互作用具有巨大的潜力，可以揭示与中子星和黑洞中发生的量子电动力学 （QED） 过程相关的物理学。超相对论电子束和强激光之间的康普顿散射可以揭示一种新的相互作用机制，称为强场 QED。在这里，我们展示了强激光场中非线性康普顿散射的实验演示，其中激光加速的数千兆电子伏特电子散射了数百个激光光子，并将它们转换为具有几百兆电子伏特能量的单个伽马射线光子。除了胞中粒子 （PIC）-QED 模拟和分析计算外，我们对伽马射线光谱的实验测量验证了强非线性范围内康普顿散射的发生，为研究非线性 Breit-Wheeler 对产生和 QED 级联铺平了道路。