Electrical Erasing of Holographic Grating in Amorphous Chalcogenide Thin Films

We investigated the electrical erasing of information recorded by a holographic method in an amorphous As 40 Ge 10 Se 15 S 35 chalcogenide thin film. Even though the amplitude of photoinduced birefringence (Δ n ) strongly depends on applied DC voltage ( V DC ), the kinetics exhibits a tendency. For V DC =0–3 V, Δ n increases with increasing induction time and eventually saturates to its maximum (Δ n max ) even though its saturation time and amplitude are not the same at different V DC 's. For V DC >4, Δ n increases rapidly at the start of the induction process (within several seconds), reaches Δ n max and then decreases very slowly. In addition, phase gratings in amorphous As 40 Ge 10 Se 15 S 35 films were formed by the holographic method and diffraction efficiency (η) was monitored in real time. Immediately after reaches its maximum (η max ), a short pulse was applied to the sample which cause a marked decrease in diffraction efficiency (η=0.25%→η≪10 -3 ).