PURPOSE: To obtain an optical element which can couple light without requiring highly precise alignment by using a refractive index modulation type hologram as an element which guides light emitted from an optical fiber into a waveguide or light emitted from the optical waveguide into the optical fiber.
CONSTITUTION: A film is formed with a photosensitive material which makes a light-irradiated part higher in refractive index than a light-unirradiated part by irradiation with light, the optical waveguide is formed by pattern exposure, and the optical fiber is arranged thereupon so that the light is emitted on the film. Then, the coherent light of a laser is split; and one light beam is guided into the optical fiber and the other is guided into the optical waveguide by end surface coupling or prism coupling in the direction wherein the optical fiber is fixed to the upper part. Consequently, the light emitted from the optical fiber interferes with the light passing through the waveguide to form interference fringes. Those interference fringes are recorded on the photosensitive material to form a hologram. Then, the optical element is manufactured by ending the reaction of the photosensitive material by irradiating the front surface with light or heating it at need.
YOSHIMURA TETSUZO
TSUKAMOTO KOJI
