A High-Performance Terahertz Back-Reflections Blocker Based on Wire Grid and Metasurface Quarter-Wave Plate

Terahertz back-reflections blocker is a kind of device that effectively isolated the harmful reflected waves in an optical system, and plays an important role in the applications of terahertz transmission and communication. In this paper, a high-performance terahertz back-reflections blocker based on the metal wire grid polarizer and metasurface quarter-wave plate is demonstrated. By designing the metasurface with high-efficiency polarization conversion and low loss, the maximum blocking efficiency reaches 50.7 dB at 1.51 THz, and the blocking efficiency bandwidth of 20 dB reaches 280 GHz in the experiment. The combination of a metasurface quarter-wave plate and a wire grid polarizer is simple in construction and has low requirements for the operating environment, such as no magnetic field, low temperature and other conditions. Moreover, the ultra-thin nature of the metasurfaces makes this high-efficiency and low-loss back-reflections blocker have broad application prospects in the field of THz integrated on-chip systems.