▎ 摘　　要

When a p- or s-polarized wave illuminates an optical system, strong inhibition of reflection can be observed at specific incident angles. Because this phenomenon does not strictly meet the definition of a classical Brewster effect, it is known as a generalized Brewster effect (GBE). Based on the fact that the graphene conductivity in the terahertz (THz) range can be dynamically modulated by optical pumping, we propose a new way to tune THz GBE in a graphene/substrate system via modulation light. A theoretical framework for the THz responses in the system tuned by modulation light has been established. We demonstrate the potential of graphene/dielectric structure as an optically tunable platform for GBE. Furthermore, we find that the tunable GBE predicted here can be classified into two categories according to physical mechanisms. One is due to the destructive interference which can be changed through tuning the modulation light. The other comes from the inhibition of the waves radiated by induced dipoles in their oscillation direction, which is dependent on the modulation light. The results obtained here can be extended to GBE systems based on other two-dimensional materials and be applied to the realization of new types of graphene-based devices.