| 摘要 |
As it is difficult to obtain optical circuits suitable for high integration with low wavelength-dependence in optical circuits using Mach-Zehnder type elements, an optical circuit according to the present invention includes: a first Mach-Zehnder type element provided with a first branch waveguide, a first branch merging device connected to one end of the first branch waveguide, and a second branch merging device connected to the other end of the first branch waveguide and having a branch configuration differing from that of the first branch merging device; and a second Mach-Zehnder type element provided with a second branch waveguide, a third branch merging device connected to one end of the second branch waveguide, and a fourth branch merging device connected to the other end of the second branch waveguide and having a branch configuration differing from that of the third branch merging device. The first branch waveguide and the second branch waveguide are each provided with a phase difference adjusting means. The optical coupling between a basic mode and a high-order mode, wherein the phase is reversed in both modes, of the second branch merging device and the third branch merging device is lower than that of the first branch merging device and the fourth branch merging device. The first Mach-Zehnder type element and the second Mach-Zehnder type element are connected via the second branch merging device and the third branch merging device. |
