Electrical Erasing of Holographic Grating in Amorphous Chalcogenide Thin Films

Abstract

We investigated the electrical erasing of information recorded by a holographic method in an amorphous As40Ge10Se15S35 chalcogenide thin film. Even though the amplitude of photoinduced birefringence (Δn) strongly depends on applied DC voltage (VDC), the kinetics exhibits a tendency. For VDC=0–3 V, Δn increases with increasing induction time and eventually saturates to its maximum (Δnmax) even though its saturation time and amplitude are not the same at different VDC's. For VDC>4, Δn increases rapidly at the start of the induction process (within several seconds), reaches Δnmax and then decreases very slowly. In addition, phase gratings in amorphous As40Ge10Se15S35 films were formed by the holographic method and diffraction efficiency (η) was monitored in real time. Immediately after reaches its maximum (ηmax), a short pulse was applied to the sample which cause a marked decrease in diffraction efficiency (η=0.25%→η≪10-3).