HOLOGRAPHIC RECORDING MEDIUM

摘要

In the present invention, a holographic recording medium comprises a chalcogenide glass comprising at least sulphur in combination with phosphorus, which undergoes a photostructural change in response to illumination with bandgap or sub-bandgap light resulting in a change of refractive index of the chalcogenide glass. It has been found that the addition of phosphorus to a sulphur-based chalcogenide glass produces a glass having properties which are advantageous as a holographic recording medium. The bandgap of the material is increased in energy compared to previously used chalcogenide glasses such that it can be used as a holographic recording medium using a commercially available frequency doubled Nd:YAG laser wavelength lambd=532 nm.