Four-level logic element based on optical bistabiiity in an uncooled thin-film semiconductor interferometer

An experimental investigation was made of an optical bistabiiity of layer ε-GaSe single crystals of thickness 0.9 µ in optical contact with a dielectric mirror. Excitation with argon laser radiation λ = 514.5 nm, focal spot diameter 60 µ, excitation power up to 80 mW) under static and dynamic conditions induced up to three consecutive optical hysteresis loops demonstrating the feasibility of operation of a thin-film bistable element as a four-level logic device.