Holographic Recording on Electron Beam Colored Sodium Chloride Crystals

Color centers produced in sodium chloride crystals by electron beam bombardment have been used for holographic recording. The holograms were constructed with the 4762-A radiation of a krypton ion laser. Reconstruction was demonstrated with both the 4762-A and 5682-A radiation of the same laser. The possibility of reconstruction in the M band, centered at 7350 A, was postulated but was not demonstrated. It was shown that the electron beam coloring technique converts complex R and M centers formed by bleaching back to F centers, making the crystals reusable. The efficiency of the electron beam coloring process and the penetration depth of the color centers as a function of the accelerating voltage were determined.