Optical bistability in the formation of spontaneous gratings in photosensitive AgCl–Ag waveguide films

Abstract

An experiment was conducted to create periodic structures in light-sensitive waveguide AgCl–Ag films on glass surface under irradiation by He-Ne laser beam (λ = 632.8 nm). So-called spontaneous gratings were formed from Ag granules within AgCl film on the interference pattern created by the beam and scattered waveguide modes. These gratings developed due to positive feedback: diffraction efficiency of spontaneous grating and intensity of waveguide mode are mutually amplified for account of the beam energy. Doubling of the spontaneous grating diffraction reflex has been found, and optical bistability has been shown to occur based on spatial analogy to stimulated temporal oscillations of a harmonic oscillator.