The invention belongs to the technical field of terahertz, relates to terahertz communication, and particularly discloses a quasi-optical
resonant cavity and a
terahertz pulse compression system. According to the invention, the pulse generation module and the
coupling compensation module are connected in parallel and are connected to the common reflector through the common coupler, so that function decoupling is realized. In a
pulse compression stage, the common coupler introduces an incident terahertz wave beam into two optical paths, and destructive interference occurs between two paths of leakage signals by adjusting the
coupling compensation module, so that zero
coupling loss is realized, and the problem of large
energy loss is solved. Meanwhile, the pulse generation module can independently adjust the
optical path of the pulse generation module to control the pulse width, and the adjustment process does not affect the optimized interference condition, so that the high robustness of adjustment is ensured. In the output stage, energy is released by switching the state of the common coupler. Compared with the prior art, low-loss accumulation and robust pulse width continuous adjustment are realized at the same time, so that the
terahertz pulse compression effect is remarkably improved.