Comparison of electromagnetic theories to predict the efficiencies of the different orders inside a volume grating

Abstract

In this work we make a comparative study between different theories to predict the efficiencies of the different orders that propagate inside a volume phase grating. For the case of a pure sinusoidal grating, transmission and reflection, the theories of Rigorous Coupled Wave Theory (RCW), Coupled Wave Theory (CW) and Kogelnik's Theory are compared. This comparison allows establishing the range of physical values where the more approximate theories, CW and Kogelnik´s Theory are applicable. On the other hand for the case of a general dielectric grating, transmission and reflection, the RCW, CW, and a thin matrix decomposition method (TMDM) are also compared. The theoretical study is also validated by comparing the theoretical results with experimental data obtained in volume phase diffraction gratings recorded on photographic emulsions. To record the volume phase diffraction gratings BB-640 emulsions were exposed to an interference pattern of light from a He-Ne laser (633 nm).