Optical waveguide recording medium and apparatus for playing the same

摘要

An optical waveguide recording medium including an optical waveguide having a photocoupler for receiving a light beam, and a plurality of refractive index-discontinuous portions aligned on the optical waveguide. One of the refractive index-discontinuous portions includes a diffraction grating having grooves extending approximately perpendicular to the lengthwise direction of the optical waveguide at equal intervals which gradually become narrower or wider as the distance of that refractive index-discontinuous portion from the photocoupler increases. This recording medium ensures that information is recorded with high density. A playing apparatus for an optical waveguide recording medium includes a light emitting means for generating a light beam with a modulated wavelength, an irradiating means for guiding the light beam to the photocoupler, a photodetecting means for performing photoelectric conversion of the light beam to provide an electric output, and a light-receiving means for guiding reflected signal light, reflected for each wavelength at the refractive index-discontinuous portions, subjected to amplitude and phase modulations, and returning via the photocoupler, to a light-receiving section of the photodetecting means.