Abstract: Diffraction characteristics of high-spatial-frequency gratings (HSF) are evaluated for application to polarization-selective computer generated holograms using two different approaches, second order effective-medium theory (EMT) and rigorous coupled- wave analysis (RCWA). The reflectivities and the phase differences for TE and TM polarized waves are investigated in terms of various input parameters, and results obtained with second order EMT and RCWA are compared. It is shown that while the reflection characteristics can be accurately modeled using the second order EMT, the phase difference created by form birefringence for TE and TM polarized waves requires the use of a more rigorous, RCWA approach. Design of HSF gratings in terms of their form birefringence and reflectivity properties is discussed in conjunction with polarization-selective computer generated holograms. A specific design optimization example furnishes a grating profile that provides a trade-off between largest form birefringence and lowest reflectivities. !31
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