A Reasonable Tolerance Multilayered Polarization-Insensitive Grating Reflector

With rigorous coupled-wave analysis (RCWA), in the study, we systematically investigate the properties of a broadband multilayered polarization-insensitive grating reflector utilized by a thin multisubpart profile. And experimental verification is carried out. Over a broadband spectrum of 1.62 similar to 1.76 mu m, the reflector experimentally demonstrates high reflectivity (R > 95%), and exists a high reflectance within 90 degrees of the polarization angles. A qualitative explanation for the physical basis of the high reflectance is provided, and the tolerance of high reflectivity properties over fabrication errors are estimated as well. The results indicate the proposed element has a favorable tolerance of fabrication error, which is useful in the fabrication of the structure.