Abstract: The present invention is directed toward an optical device and a drive voltage supply device, which prevent occurrence of a DC drift and enable stable selection of light of desired wavelength without deteriorating a filtering characteristic. The optical device comprises a substrate having an electrooptical effect; an optical waveguide formed in this substrate; a plurality of comb electrode pairs which are arranged side by side along the optical waveguide, can apply an electric field for said electrooptical effect, and are formed from respective pairs of comb electrodes; and drive voltage supply means capable of supplying a drive voltage to said comb electrode pairs such that the voltage changes with time.

Abstract: In relation to an optical modulator (e.g., an RZ optical modulator) formed from a plurality of Mach-Zehnder optical modulators, in an attempt to make the optical modulator compact and realize a low drive voltage, the optical modulator is formed by comprising a plurality of Mach-Zehnder optical modulators, each including a substrate exhibiting an electro-optical effect, an optical waveguide formed on the substrate, and electrodes formed in the vicinity of the optical waveguide. The plurality of Mach-Zehnder optical modulators are arranged on the substrate and connected into multistage.

Abstract: An optical device module includes an optical device with a plurality of electrodes disposed at predetermined positions, a substrate disposed oppositely to the optical device and with wiring patterns for connecting to the electrodes, and a wiring which connects the electrodes to the wiring patterns.

Abstract: In a variable optical delay circuit to be used for compensation for polarization mode dispersion of an optical signal and for other purposes, there are provided a first birefringent member, a second birefringent member and a variable optical rotator interposed between the first birefringent member and the second birefringent member for varying a polarization state of light outputted from the first birefringent member. The birefringent members and the variable optical rotator are disposed on the same optical axis, and the optical axis of each of the birefringent members is set to perpendicularly intersect a traveling direction of inputted light. Therefore, by varying the optical rotation angle of the variable optical rotator, an arbitrary delay quantity corresponding thereto is obtainable in a continuous (analog-like) fashion without undergoing spatial separation between polarization components of the inputted light and varying the intensity (loss) of each of the polarization components.

Abstract: An object of the invention is to provide a Mach-Zehnder type optical modulator that can reduce wavelength chirp occurring in a modulated light, and also can reduce an optical loss with a small sized configuration. To this end, according to the present Mach-Zehnder type optical modulator, in a configuration where optical waveguides and a coplanar electrode are formed on a substrate having an electro-optical effect, a polarization inversed region is formed in a part of an interaction portion of the substrate, and a signal electrode is arranged above one of parallel waveguides in a polarization inversed region and is arranged above the other parallel waveguide in a non-inversed region. Furthermore, a surface area of the substrate positioned on both sides of each of the parallel waveguides is lowered to provide a ridge structure section, and a buffer layer is formed on a ridge side face thereof.