Hologram Diffraction Efficiency
This chapter reviews several methods including Fourier analysis of thin gratings, approximate coupled wave analysis of thick or volume gratings, and rigorous coupled wave analysis which while more complex provides the most comprehensive treatment of grating diffraction. The diffraction efficiency describes the amount of optical power diffracted by a hologram into a desired wavefront. The diffraction efficiency of gratings with absorption and phase modulation, transmission and reflection modes of operation, and with surface relief modulation are investigated. The diffraction efficiency is equal to the ratio of the diffracted optical power in a particular order to the incident optical power. Coupled wave analysis is one of the most useful and intuitive methods for modeling the diffraction efficiency of a volume or thick hologram. The rigorous models can be applied to a grating of any type because the diffraction process is evaluated as a fundamental electromagnetic problem.