An optical coupling method, characterized by situating a photosensitive material whose refractive index changes and which is insolubilized with light irradiation, in the entirety or part of the area between a plurality of optical devices which are arranged with such positional relations that light-emitting ends of the optical devices are generally opposed to each other, irradiating the photosensitive material with light from one or a plurality of optical devices of a wavelength at which its refractive index changes and the material is insolubilized, and using an optical waveguide or refractive index distribution, which does not correspond to writing light power distribution, formed while inducing self-focusing of the writing light, whose power distribution changes during writing process, and insolubilizing the photosensitive material, to accomplish optical coupling between the optical devices wherein, when the light of a wavelength sensed by said photosensitive material is irradiated from the two or more optical devices to form the waveguide or refractive index distribution, at least two optical devices are provided in such an orientation that the refractive index changes produced by light therefrom exert an additional influence on each other.