Polarization rotation Bragg grating using Si wire waveguide with non-vertical sidewall

We report polarization independent Bragg grating wavelength filter using polarization rotation. A non-vertical waveguide sidewall and antisymmetric grating structure can be used to generate the polarization rotation of the fundamental modes. The diffraction efficiencies and peaks becomes the same for two orthogonal input polarizations. The concept was verified by simulation and experiment.