| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical modulator having high signal quality, in particular, a high-performance optical modulator which has suppressed deterioration in modulation characteristics due to intensity difference of signal components caused by variation in manufacture of the optical modulator and the like and which requires no complicated manufacturing process. SOLUTION: The optical modulator 1 includes: a substrate 4 having an electrooptical effect, an optical waveguide 5 formed on the substrate, and control electrodes 61 to 65 for controlling an optical wave propagated through the optical waveguide. The optical waveguide 5 is constituted of a main Mach-Zehnder (MZ) type waveguide 50 having two branched waveguides and sub Mach-Zehnder (MZ) type waveguides 51 and 52 provided in the branched waveguides. Each branched waveguide includes: an optical intensity adjusting means (constituted of e.g. optical waveguides 53 and 54 and the control electrodes 63 and 64) connected to the sub Mach-Zehnder type waveguides 51 and 52 in series; and a voltage control circuit monitoring a portion of the optical wave propagated through the branched waveguides and adjusting voltage applied to the optical intensity adjusting means. COPYRIGHT: (C)2010,JPO&INPIT
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