  Measurement and analysis of diffraction parameters of thick transmission
holographic phase gratings recorded on PHC-488 photopolymer are presented.
Precision determination of the spatial grating period is executed by Bragg
angle measurement for two precisely known wavelengths in the first diffraction
order and also by Bragg angle measurement on one wavelength in the first and
second diffraction orders. Determination of actual grating thickness and depths
of spatial modulation of a holographic recording, which are responsible for
their main optical characteristics, is carried out with the application of H.
Kogelnik 2-wave coupled model. Calculated and experimental Bragg angles in two
orthogonal orientated planes of linear polarized laser light were used to
confirm theoretical model with experimental results. Extreme values of the
diffraction parameters, efficiency and spectral resolution, important for
holographic phase grating applications are analyzed.
