Polarization-Independent Grating With The Zeroth Order Suppressed

In this paper, a polarization-independent grating with the suppression of the zeroth order under normal incidence is introduced. In order to suppress the zeroth order, the rigorous coupled-wave method is used to optimize height of the grating groove and the thickness of the connecting layer, where the total efficiency of the +1st order and the -1st order is greater than 90%. The modal method can explain the physical mechanism of the grating transmission and the 0th order suppression. Then the process tolerance of the grating is studied, which provides a basis for the design of the zeroth order suppressed.