| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical circuit with low loss which has high stability and reliability and a function to separate polarized waves, which can be easily manufactured and which is inexpensive. SOLUTION: The optical circuit has optical waveguides 12a, 12b, 12c, 12d each consisting of a core part produced from quartz as the main material where the light propagates and a clad around the core and having a lower refractive index than the core on a planar substrate 11. The optical circuit is composed of optical couplers 14, 15, arm waveguides 16, 17 connected in series with the optical couplers 14, 15, and a Mach-Zehnder interferometer consisting of the optical couplers 14, 15, all formed by the optical waveguides 12a, 12b, 12c, 12d. In the method of manufacturing the circuit, two or more position in the two arm waveguides 16, 17 in the Mach-Zehnder interferometer circuit are irradiated with light in the UV region or visible region in such a manner that the irradiated areas have different widths. |
