Design of annular blazed grating for rotating beam

We designed an annular blazed grating to achieve maximum optical power in the +1st transmitted order at a fixed diffraction angle. We performed theoretical analysis and simulations on the designed grating, where the incident beam (wavelength: 1550 nm) was perpendicular to the grating surface. The diffraction efficiency in the +1st transmitted order was dependent on the blaze angle (or modulation depth) and period for a refractive index of 1.49. The diffraction efficiency in the +1st transmitted order was maximum (85.94%) at a modulation depth and period of 2.18 μm and 3.96 μm, respectively, and the corresponding diffraction angle was 45.3°.