Method of optical enhancement during the exposure process on thin films of vitreous chalcogenide semiconductors

A method for the storage of information on vitreous chalcogenide semiconductor (VCS) thin films by timing exposures so as to produce photoinduced changes (PIC) in the VCS layers, was published at an earlier date. This paper refers to an interesting phenomenon observed during holographic recording on VCS induced by the homogeneous light produced by a HE-Ne laser, for hologram control or reconstruction. This effect can be regarded as self- enhancement, as the holographic image is enhanced during its reconstruction. The exposures that are greater than Hmax, at first decrease the self-enhancement effect and can even erase the optically recorded data. The speed of optical erasure tends to increase for longer exposures. However, this very effect of erasure of holograms recorded on VCS layers may be used as a basis of reconstruction, provided the PIC was made by lasers of sufficient power.