Abstract: In an optical circuit including multi-dimensional photonic crystals, in which the optical circuit has a structure (33), such as a light emitting member or a light receiving member, having a natural resonance frequency, another structure (34) having a natural resonance frequency slightly differing from the natural resonance frequency of the structure (33) is arranged in the vicinity of the structure (33) to control the directivity of localization and propagation of an electromagnetic field, light emission and light reception in a spatial region including the above structures in the multi-dimensional photonic crystals, in order to permit functional operations to be realized.

Abstract: In an optical circuit including multi-dimensional photonic crystals, in which the optical circuit has a structure (33), such as a light emitting member or a light receiving member, having a natural resonance frequency, another structure (34) having a natural resonance frequency slightly differing from the natural resonance frequency of the structure (33) is arranged in the vicinity of the structure (33) to control the directivity of localization and propagation of an electromagnetic field, light emission and light reception in a spatial region including the above structures in the multi-dimensional photonic crystals, in order to permit functional operations to be realized.

Abstract: A one-dimensional photonic crystal has a spatial distribution in which the refractive index periodically varies in a first direction that light is caused to be propagated and in which the refractive index is uniform in a second direction perpendicular to the first direction. An antireflective coating structure for the one-dimensional photonic crystal includes a thin-film having a refractive index and a thickness determined by a predetermined calculation method. A two or three-dimensional photonic crystal comprises two or more media that have different refractive indexes and are arranged in a two or three-dimensional pattern. An antireflective coating structure for the two or three-dimensional photonic crystal includes a thin-film comprising one of the media included in the photonic crystal. In the structure, the thin-film is disposed on an end face of the photonic crystal so as to increase the incident efficiency of light entering the photonic crystal.

Abstract: Disclosed in a method and a device in which a wave number of light in the waveguide mode of a photonic crystal optical waveguide is matched with that of the incident light, or a intensity ratio of electric field to magnetic field of the light in the waveguide mode of the photonic crystal optical waveguide is matched with that of the incident light, and furthermore, in addition to the method above, the distribution of light intensity on the incident end surface in the waveguide mode of the photonic crystal optical waveguide is matched with that of the incident light. A photonic crystal optical waveguide and channel optical waveguide are joined together, and the structure of the channel optical waveguide is wedge shaped in the joint section.

Abstract: A one-dimensional photonic crystal has a spatial distribution in which the refractive index periodically varies in a first direction that light is caused to be propagated and in which the refractive index is uniform in a second direction perpendicular to the first direction. An antireflective coating structure for the one-dimensional photonic crystal includes a thin-film having a refractive index and a thickness determined by a predetermined calculation method. A two or three-dimensional photonic crystal comprises two or more media that have different refractive indexes and are arranged in a two or three-dimensional pattern. An antireflective coating structure for the two or three-dimensional photonic crystal includes a thin-film comprising one of the media included in the photonic crystal. In the structure, the thin-film is disposed on an end face of the photonic crystal so as to increase the incident efficiency of light entering the photonic crystal.