| 摘要 |
PROBLEM TO BE SOLVED: To achieve an optical modulator with no wavelength dependence with a low loss.SOLUTION: In an optical modulator 1, a first coupler 2 branches input light and outputs first output light and second output light. A first Mach-Zehnder interferometer 3 modulates intensity of the first output light outputted from the first coupler 2 and outputs third output light. A second Mach-Zehnder interferometer 4 modulates intensity of the second output light outputted from the first coupler 2 and outputs fourth output light. A second coupler 5 combines the third output light outputted from the first Mach-Zehnder interferometer 3 and the fourth output light outputted from the second Mach-Zehnder interferometer 4, and branches the combined light and outputs fifth output light and sixth output light. An action length of a branch portion of the first coupler 2 and an action length of a branch portion of the second coupler 5 are lengths such that wavelength dependence of a branch ratio of the first coupler 2 and wavelength dependence of a branch ratio of the second coupler 5 have an opposite relationship. |
