Optimal temperature for recording holograms in NaCl-Ca crystals

The dependence of the diffraction efficiency of Fourier holograms on the temperature of X-ray-tinted NaCl-Ca crystals was studied experimentally. The holograms were recorded with a He-Cd laser (441.6 microns) and were reconstructed with a He-Ne laser (632.8 microns). At the optimal recording temperatures of 105 to 110 C, the maximal diffraction efficiency was 7.6% for the He-Cd laser, and 3.9% for the He-Ne laser at a hologram thickness of 0.66 mm. The activation energy of the recording process was 0.62 eV. The dependence of the diffraction efficiency on the initial optical density of the crystal was investigated.