ANALYSIS OF MULTIPLEXED-REFLECTION HOLOGRAPHIC GRATINGS

Multiplexing is an attractive option for obtaining multiline holographic notch reflectors. We discuss two methods for analyzing multiplexed holograms, i.e., coupled-wave theory and thin-film-matrix formulation. A coupled-wave approach for modeling multiplexed holograms is developed. It is found that the first-order theory of Kogelnik is a valid approach if the multiplexed gratings are nondegenerate. However, if the gratings are near degenerate, the exact thin-film matrix method must be used. Specifically, it is shown that, in the case of degenerate gratings, the diffraction efficiency depends critically on the initial phase of each grating. Numerical results using both methods are presented and compared. © 1990 Optical Society of America.