Two port reflective grating with the cancellation of the zeroth order

In this paper, a two-port reflective grating with the cancellation of the zeroth order is introduced. The grating uses an Ag reflective metal grating structure. Under a normal incidence of light with a wavelength of 1550 nm, for both TE and TM polarizations, the grating can output in ±1st orders. In addition, the efficiency of the 0th order reflected light is less than 1%. Optimized grating parameters are obtained by using rigorous coupled-wave analysis. Furthermore, the complex physical mechanism of multimode superposition coupling in grating can be well explained by modal method