▎ 摘　　要

The first experimental demonstration of nonlinear terahertz difference-frequency generation in a hybrid graphene meta-device is reported. Decades of research have revealed that terahertz-wave generation is impossible in single-layer graphene. This limitation is overcome and nonlinear terahertz generation by ultra-short optical pulse injection is demonstrated. This device is an essential step toward atomically thin, nonlinear terahertz optoelectronic components.