Optical photoinduced phenomena and holographic recording in amorphous As-Se thin films

The effect of light-induced photodarkening in amorphous As100-xSex (x=40 divided by 98) thin films for different thickness and film composition was investigated. It was established a strong dependence of the red shift of the absorption edge and refractive index under light irradiation on the film composition and thermal treatment. It was established that the more sensitive films to photodarkening and holographic recording correspond to non-stoichiometric compositions of As55Se45 and As60Se40 glasses. The experimental results are interpreted in terms of structural optical polymerization process, which includes the transformation of As4Se4 and Se-2 structural units in homogenius AsSe3/2 network.