Summary: | Holographic techniques were used to study the optical properties and bistable behavior of Ga-doped cadmium fluoride. Ga impurities form bistable centers in CdF���. Illumination causes a phototransformation from a deep to shallow center, which causes a change in the index of refraction. This change is caused by a redistribution of electrons in the centers, and is known as the photorefractive effect.
The photorefractive effect makes it possible to write holographic patterns into the material. Using intersecting laser beams, a holographic grating was written into the sample, and the behavior of this grating was studied. The decay and efficiency of the grating are temperature dependent. The thermal decay that is responsible for erasing the grating is a two-center process. The thermal activation energy between the centers is about 780 meV. === Graduation date: 2000
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