Broadband and polarization-insensitive subwavelength grating ref...

We propose a polarization-insensitive and broadband subwavelength grating reflector based on a multilayer structure. The reflector has an overlapped high reflectivity (>99.5%) bandwidth of 248 nm between the TE and the TM polarizations, which is much higher than the previously reported results. We believe this subwavelength grating reflector can be applied to unpolarized devices.