Visible metasurfaces and ruled diffraction gratings: a comparison

Metasurface based and physical ruling based diffraction gratings function by controlling the phase of light, but the origin of the phase control is different. Here we compare the simulated optical response of a 1800 lines/mm ruled diffraction grating blazed for 650 nm light to the response of a 1800 lines/mm phase grating meta-surface designed for efficiency in the visible. The efficiencies are comparable; the transverse electric polarized efficiency of the meta-surface based grating is similar to the transverse magnetic polarized efficiency of the ruled-grating. However, due to the different mechanisms of phase accrual, the meta-surface based grating does not exhibit grating anomalies and has low efficiency for transverse magnetic polarized light.