The characteristics of optical recording and changes in the hologram parameters of the amorphous quaternary system Cu-As-Se-I are described. The dependence of the relative contrast of recording on the exposure and transparency properties of the film before and after erasure is the basis for discussion of these processes. Investigation into the dependence of diffraction efficiency of the holograms indicates that these quantities are determined by the thin film composition.
IntroductionSome amorphous semiconducting materials have recently been studied as potential media for storing optical information. One of the fundamental problems is the reversibility of these processes, and the mode of erasing the optical pulses recorded. Earlier investigations of photoinduced processes in amorphous chalcogenide semiconductors (ChAS) have shown that these materials possess a relatively high resolution, reversibility of recording, and other properties that are of importance for their use in holography and for equipment for optical treatment of information [1, 2] (Table I).A series of previous experiments has been conducted on a very wide class of multicomponent amorphous systems: As-S, As-Se, M-As-B w, As-BW t, and M-As Se-I (M = metal, B w = S or Se) [3][4][5][6]. It has been observed that practically all these glasses are, to a smaller or greater extent, photosensitive to a certain wavelength of laser radiation, and the relevant parameters are dependent on the composition of the glass and conditions of its preparation. Four-component systems offer special possibilities because one can substantially influence the properties of the system simply by changing the ratio of their components. This is primarily concerned with the spectral interval of photosensitivity and characteristics of the recorderasure processes. It should be pointed out that a relatively complex technology of obtaining quaternary glasses and of thin films on their bases have been the reason why the processes of optical recording in these systems have received relatively little attention.We report here the results of our investigations of the optical recording processes and characteristics of holograms in the Cu-As-Se-I system.