Optimization of holographic data recording in photochromic glasses

Hie diffraction efficiency of holograms formed by recording with a helium–cadmium laser was calculated on the basis of the experimentally determined bulk distributions of the absorption coefficient of photochromic glasses subjected to different exposures. A comparison with direct holographic experiments indicated that the calculated results gave a fair estimate of the diffraction efficiency expected under the selected recording conditions. The maximum diffraction efficiency was 2.15%. The highest value of this efficiency and good sensitivity were obtained for the optimal thickness of the glasses, which was 1.5–2 mm.