Abstract: There is provided an optical device including a substrate having an electro-optical effect, a plurality of optical modulators including bias electrodes to which a bias voltage is applied so as to generate an electric field from one of the bias electrodes to another of the bias electrodes, and the bias electrodes of the optical modulators being disposed above the substrate, and a partition conductor to reduce influence of the electric field from the bias electrode of a first optical modulator to an optical waveguide of a second optical modulator, the partition conductor being disposed above the substrate.

Abstract: In an optical waveguide device, in a cross direction intersecting an extension direction of waveguide sections, one or more bridge portions of a ground electrode closer to a center of stress distribution of a stress due to a support member, and one or more bridge portions of a ground electrode farther from the center of stress distribution are formed with different shapes. The structure of the ground electrodes is devised so that a stress negating the difference in stress characteristics between the plurality of waveguide sections, generated by the stress applied from the support member to a substrate, is applied from the ground electrode to the substrate.

Abstract: An optical device includes first and second optical modulators formed on a substrate having electro-optical effect. The first optical modulator includes a first optical waveguide; a first signal electrode configured to provide a first data signal for the first optical waveguide; and a first DC electrode, arranged at an output side of the first signal electrode, and configured to provide first DC voltage for the first optical waveguide. The second optical modulator includes a second optical waveguide; a second signal electrode configured to provide a second data signal for the second optical waveguide; and a second DC electrode provided, arranged at an input side of the second signal electrode, and configured to provide second DC voltage for the second optical waveguide. Input portions of the first and second signal electrodes are arranged at a same side edge of the substrate.

Abstract: According to an aspect of an embodiment, an optical device comprising: a first modulator for independently modulating first light having a first predetermined polarization mode; a second modulator for independently modulating second light having a second predetermined polarization mode; and a polarization beam coupler having a first port, a second port, a third port, and a fourth port; the polarization beam coupler for inputting the first light from the first modulator via the first port, inputting the second light from the second modulator via the second port, outputting the first light via the third port and inputting reflected and polarization converted light on the first light by a wave plate and a mirror, and outputting the first light having the converted polarization mode and the second light having the predetermined polarization mode via the fourth port.

Abstract: An optical waveguide device including a dielectric substrate and a folded waveguide formed on the substrate, including a first waveguide and a second waveguide, one part of the first waveguide being connected to one end of the second waveguide at a first coupling portion, the other end of the second waveguide connected to another part of the first waveguide at a second coupling portion, the first waveguide being straight or curved with a radius of curvature larger than or equal to a first curvature radius, and the second waveguide being straight or curved with a radius of curvature smaller than the first curvature radius. An outer groove is formed on the substrate along an outer peripheral of the folded waveguide, an input-side inner groove is formed on the substrate near a first coupling portion, and an output-side inner groove is formed on the substrate near a second coupling portion.

Abstract: A method of manufacturing an optical device involves forming patterns on a dielectric substrate. The patterns include a waveguide pattern having a folded part, a conductor pattern positioned on an outer peripheral side of the folded part, and a dummy pattern that connects the folded part and the conductor pattern. The method further involves performing heat diffusion processing on the dielectric substrate on which the patterns have been formed at the forming, to make the waveguide pattern into an optical waveguide.

Abstract: There is provided an optical device including a plurality of Mach-Zehnder modulators; and an input branching waveguide to split an input light so as to direct the resulting light to the plurality of Mach-Zehnder modulators; the Mach-Zehnder modulator comprising: a splitter coupled to the input branching waveguide; pair of waveguides coupled to the splitter; a combiner coupled to the pair of waveguides; and a signal electrode to apply signals to the pair of waveguides; wherein the splitters are disposed in a different orientation to each other.

Abstract: In an optical modulator, lights that have been branched by an input optical branching section are input via curved waveguides to a plurality of optical modulation sections arranged in parallel on the same substrate. In the optical modulation sections, optical branching sections of an MZ type optical waveguide are arranged shifted to an output side in the longitudinal direction (x direction) of the substrate, corresponding to an arrangement of input ends of signal electrodes. As a result, even if the input ends of the signal electrodes of the respective optical modulation sections are arranged side by side with a predetermined spacing on one side face of the substrate, input light can be applied to the respective optical modulation sections at low loss, without incurring an increase in the drive voltage.

Abstract: In an optical modulator, an intermediate substrate is provided separate from a main substrate on which a plurality of optical modulation sections are provided in parallel, and signal lines corresponding to the optical modulation sections are formed on the intermediate substrate. The signal lines are connected to signal electrodes corresponding to the main substrate, and have electrical lengths that are different from each other. Furthermore, the propagation loss per unit length in the signal lines on the intermediate substrate is preferably less than the propagation loss per unit length in the signal electrodes on the main substrate. As a result, even if a plurality of optical modulation sections are arranged in parallel, and the input ends of the signal electrodes of the optical modulation sections are arranged side by side on one side face of the substrate, synchronized modulation light of a low noise at a wide band width can be output from the optical modulation sections.

Abstract: In an optical modulator, respective lights for where one input light has been branched, are input via a curved waveguide to a plurality of optical modulation sections arranged in parallel on the same substrate. In a Mach-Zehnder type optical waveguide, a spacing between the pair of branching waveguides of the adjacent optical modulation sections, is formed so as to become wider in the vicinity of a border of an input side polarization inversion region than in the vicinity of a start point of an interaction portion. As a result, even if a signal electrode of the optical modulation sections shifts at the boundary portion of the polarization inversion region, the spacing between the signal electrodes does not become narrow, and hence the radius of curvature of curved waveguides for guiding the input light to the respective optical modulation sections can be increased, so that it becomes possible to apply input light to the optical modulation sections at low loss.

Abstract: An optical modulator comprising; an optical waveguide in which input light propagates; a signal electrode having an end portion in which signal microwave is input and having an interaction area in which the signal microwave interacts with the light propagating in the optical waveguide; and, a ground electrode forming a coaxial structure with the signal electrode, wherein, width of the end portion is greater than width of the interaction area and thickness of the end portion is less than thickness of the interaction area. Also disclosed is an optical modulator, further comprising a substrate having an electro-optic effect; and, a buffer layer on the substrate, wherein, the signal electrode and ground electrode are formed on the buffer layer, and thickness of the buffer layer near the end portion of the signal electrode is greater than thickness of the buffer layer near the interaction area.

Abstract: The optical device includes an outer Mach-Zehnder interferometer having two outer arm waveguides; and two multilevel modulators, each formed on one of the outer arm waveguides, which perform multilevel modulation on input light independently of each other, one of the multilevel modulators including an inner Mach-Zehnder interferometer having two inner arm waveguides, and two signal electrodes which provide electric fields that are to interact with light propagates through the inner Mach-Zehnder interferometer, the inner Mach-Zehnder interferometer or the signal electrodes cross an even number of times at crossing points so as to alternately interact with the electric fields provided by the signal electrodes, a part of a light propagation region of the inner arm waveguides which region has a boundary defined by at least one of the crossing points forms a polarization inversion region. The optical transmitter includes the above optical device.

Abstract: An electronic device in which a signal electrode has a bent portion. Earth electrodes are formed with the signal electrode between. A width of a gap at the bent portion between the signal electrode and each earth electrode is narrower than a width of a gap at both ends of the bent portion between the signal electrode and each earth electrode.

Abstract: An optical communication device includes a substrate which has electro-optical effect; a first optical modulator which has a pair of waveguides formed in the substrate; a second optical modulator which has a pair of waveguides formed in the substrate; a waveguide coupler which is provided in an output of the first optical modulator, the waveguide coupler being able to couple and branch light propagating through the pair of waveguides of the first optical modulator; and a delay connecting section which gives differential delay to the output branched by the waveguide coupler and inputs the output to the pair of waveguide of the second optical modulator. As a result, the optical communication device and optical device in which insertion loss is reduced compared with the conventional optical modulator can be provided.

Abstract: An optical waveguide device includes; a substrate having an electro-optic effect, and a first optical waveguide and a second optical waveguide formed substantially in parallel on a top face of the substrate. A groove is formed for cutting only the first optical waveguide, of the first optical waveguide and the second optical waveguide. The groove penetrates from the top face to a bottom face of the substrate. Such a groove can be formed for example by fixing a side face of the substrate on the second optical waveguide side to a supporting base of a dicing machine so that the first optical waveguide is positioned on an upper side and the second optical waveguide is positioned on a lower side, and advancing the dicing saw from the bottom face side to the top face side of the substrate.

Abstract: A method of manufacturing an optical device involves forming patterns on a dielectric substrate. The patterns include a waveguide pattern having a folded part, a conductor pattern positioned on an outer peripheral side of the folded part, and a dummy pattern that connects the folded part and the conductor pattern. The method further involves performing heat diffusion processing on the dielectric substrate on which the patterns have been formed at the forming, to make the waveguide pattern into an optical waveguide.

Abstract: In a reactor core, a gap section between a plurality of core material portions is constituted by adhering and fixing the gap section through a spacer, and a resin is arranged vertical to the adhering surface between the core material and the spacer, for sandwiching at least a part of the core material. The resin material is preferably a molded material.

Abstract: An optical waveguide device is disclosed wherein the modulation efficiency for a driving voltage is improved. The optical waveguide device includes a substrate having an electro-optic effect, an optical waveguide formed on the substrate, an electrode section adapted to supply an electric field for carrying out phase modulation synchronized with a clock signal to the optical waveguide, and a Mach-Zehnder interferometer connected to the downstream side of the optical waveguide and including two branching waveguides having optical lengths different from each other.

Abstract: To reduce wavelength chirp and produce multi-valued signal light that can be readily demodulated on a receiver side, a Mach-Zehnder type optical modulator includes an incident waveguide that branches input light, a pair of optical waveguides that respectively transmit the branched light and exhibit an electro-optic effect, a pair of signal electrodes arranged along the optical waveguides, and an exit waveguide that outputs an interfered light of the light transmitted through the optical waveguides. Furthermore, at a boundary, the polarity of each of the optical waveguides reverses, and either the optical waveguides or the signal electrodes cross each other.

Abstract: The present optical waveguide device, which improves the optical phase rotation efficiency with respect to activation voltage, includes: a substrate having electro-optic effects; a Mach-Zehnder optical waveguide formed on the substrate; and a signal electrode. The signal electrode is formed in an integrated manner such that an electric signal for applying the electric field travels from an upper part of either one of the two interference optical waveguides, which form the Mach-Zehnder optical waveguide, to an upper part of the other one of the two, and also, a periodical polarization characteristics region, in which regions opposite to each other in polarization are alternately arranged, being provided for a part of the other one of the interference optical waveguides on the substrate.