| 摘要 |
PROBLEM TO BE SOLVED: To solve such problems that the latitude for the design of an optical circuit is low and designing a circuit having less sensitivity to manufacture errors is difficult because of the conventional assumption that the basic periodical length and direction of the basic period in the structure of a photonic crystal as the structural material of optical circuit parts are basically constant in the plane or volume of the crystal on the analogy of a natural crystal such as a semiconductor. SOLUTION: In a two-dimensional or three-dimensional photonic crystal having the feature that it is produced by depositing layers of substances on a substrate, the basic periodical length or the direction of the period of the crystal are not uniform in the relation of the position in the crystal, but are gradually varied or varied stepwise with the position and if necessary, varied in the perpendicular direction to the substrate. Namely, the crystal features a modulated grating. By this technique, wide latitude of processing and latitude of functions are obtained in photonic crystal optical circuit parts. |
