CALCULATION OF SHEAR ANGLES IN HOLOGRAPHIC GRATINGS RECORDED IN BLEACHED SILVER-HALIDE EMULSIONS

Shearing phenomena in holographic gratings formed in bleached silver-h alide emulsions due to chemical processing are evaluated. These effect s are introduced because of the inability of emulsion-thickness change s to explain the anomalous detuning of the peak diffraction efficiency from the expected Bragg condition. Experimental results obtained with transmission and reflection gratings are presented and discussed cons idering shearing effects, and the values of the shear angles calculate d from the Bragg-angle deviation measurements are also provided. In or der to separate the shearing phenomenon and the shrinkage of the emuls ion layer, a rehalogenating bleach without fixing is used because this bleach bath introduces a minimal change in the thickness of the emuls ion. The influences of exposure, spatial frequency and slant angle on shear angles are briefly analyzed and discussed.