Comparative study of the accuracy of the PSM and Kogelnik models of diffraction in reflection and transmission holographic gratings

摘要

Calculated diffractive efficiencies in the visible spectral band from lossless planar holographic gratings are studied using the PSM and Kogelnik models of diffraction for the case of the σ-polarization. The results are numerically compared with rigorous coupled wave calculations over a wide parameter space covering both transmission and reflection geometries. For most reflection gratings, the PSM model is shown to consistently provide a marginally superior estimation of the diffractive efficiency. This is particularly evident in a clearly superior description of the diffractive sideband structure for most gratings, both in terms of angle and wavelength. For the transmission grating, the PSM model continues to provide a relatively good description of diffraction at low permittivity modulations and lower incidence angles with respect to the grating plane normal. However, overall Kogelnik’s theory is shown to provide a somewhat superior estimation of diffractive efficiency and a clearly superior description of the diffractive side-band structure in the transmission case.