PRODUCTION OF OPTICAL WAVEGUIDE

摘要

PROBLEM TO BE SOLVED: To increase safeness and simplicity and to decrease thermal strain and the like by forming a quartz-based optical waveguide layer on a substrate by using a source material containing an org. material and irradiating a part of the layer with UV rays to modify the refractive index in the part. SOLUTION: In the production of an optical waveguide comprising a quartz- based material, a quartz-based optical waveguide layer is formed on a substrate by using a source material containing an org. material by chemical vapor phase deposition under normal pressure (AP-CVD), and then at least a part of the optical waveguide layer is irradiated with UV rays to modify the refractive index of the part irradiated with UV rays. As for the substrate for the optical waveguide, silicon or quartz substrate is used. The optical waveguide layer consists of, for example, SiO2 +P2 O5 (clad layer) and SiO2 +P2 O5 +GeO2 (core layer). The optical waveguide layer substantially has an absorption band in the UV range so that the refractive index in the part irradiated with UV rays can be changed. Therefore, it is preferable that the wavelength region of the UV rays for irradiation is included in the absorption band of the optical waveguide layer.