Spectral hole burning and holography. III. Electric field induced interference of holograms

The electric field induced superposition of holograms recorded by spectral hole burning is investigated. Holograms have been burned at adjacent positions in a plane defined by wavelength and electric field. Application of an appropriate electric field to the sample causes the components of adjacent holograms to overlap as the spectral holes split due to Stark shifts of molecular transition frequencies. The diffraction efficiency of such superimposed holograms depends on their relative phase and has been studied theoretically and experimentally. It is shown that for zero phase difference, constructive interference leads to a strong diffraction efficiency whereas for a phase difference of π, the gratings cancel leading to zero diffraction efficiency. Experiments have been performed with the dye cresyl violet in a polyvinylbutyral film at a temperature of 1.7 K and the data are compared with computer simulations.