| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a Y branch waveguide capable of reducing propagation loss while a light propagation mode is secured. <P>SOLUTION: This invention relates to a method of manufacturing a Y branch waveguide in which an in-branch light leak-preventing part 3 is formed in a prescribed region that is interposed between the outputting end cores 1a, 1b and that is near the inputting end core li, the in-branch light leak-preventing part comprising a photonic crystal having a refractive index periodic structure composed of a plurality of mediums of different refractive indexes. For manufacturing this Y branch waveguide, in a periodic structure forming process for forming the refractive index periodic structure, a prescribed region is formed by one kind of medium among a plurality of mediums. Then, the laser irradiation part is machined by convergently irradiating it with a pulsed laser having a pulse width that causes no heat damage around a laser irradiation part in the prescribed region, wherein an image forming optical system is utilized that is provided with a mask having a pattern similar to a machining shape corresponding to the refractive index periodic structure. By so machining the laser irradiation part, the refractive index thereof is adjusted. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
