| 摘要 |
PROBLEM TO BE SOLVED: To allow monitoring in a remote site by simple constitution. SOLUTION: Films 6, 7 different in thermal expansion coefficient with each other are formed in the vicinities of respective branched optical waveguides, in an optical waveguid constituted to be branched into two optical waveguides on an optical substrate and to be thereafter joined again into one optical waveguid. A film having a thermal expansion coefficient different from that of the optical substrate is allowed to be formed only in the vicinity of the optical waveguid on one side of the branched optical waveguides. Alternatively, films different in thermal expansion coefficient with each other are formed in the vicinities of respective branched optical waveguides, in an optical waveguid constituted to branch one optical waveguid provided on the optical substrate into two optical waveguides, constituted to reach thereafter to an end face of the optical substraet to be reflected to reverse the advancing direction of waveguide light in the end face, and constituted to be multiplexed again thereafter. Film having a thermal expansion coefficient different from that of the optical substrate is allowed to be formed only in the vicinity of one side optical waveguid out of the two branched optical waveguides. |
