PURPOSE: To realize optical integration which is capable of recording, reproducing and erasing with high sensitivity, by constituting a bismuth sillenite group substrate, providing an optical waveguide layer which has a higher refractive index than the substrate and absorbs no waveguide light, and using a part of said layer as a hologram recording layer.

CONSTITUTION: A substrate 1 consists of a crystal body of Bi12SiO20, Bi12GeO20, etc., on which an optical waveguide layer 2 having a higher refractive index than the substrate and is transparent in its visible area is obtained by adding Ga, etc. to a material of the substrate 1 and by a liquid phase epitaxial method. On a part of this waveguide layer 2, a space 10 is provided by means of chemical etching, on which a hologram recording layer 3 being the third layer is formed by use of Bi12TiO20 which has no adding agents. By polishing its surface, an optical waveguide hologram is obtained. The hologram recording layer 3 has a higher refractive index than the substrate 1, and has a photoconductive effect. When an electrode 8 is provided on the surface, and a DC electric field is applied by an electric power supply 9, a photoelectric effect is generated, and bright reproduced light 7 is obtained. In this way, it is possible to obtain a hologram which is capable of recording, reproducing and erasing with high sensitivity.