Abstract: An optical device having a substrate having an electro-optical effect, an optical waveguide formed in the substrate, and an electric field emission electrode, and an electric field convergence electrode to which an electric field emitted from the electric field emission electrode converges. The optical waveguide is formed such that light propagating through the optical waveguide passes through an area under the electric field emission electrode or an area under the electric field convergence electrode and then passes through a remaining electrode. As a result, even when an interaction length is increased, the optical device acquires (increases) a modulation index appropriate to the increase in interaction length, thereby diminishing a drive voltage.

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: Disclosed is a low cost, low magnetostriction body which is decreased only in magnetostriction while maintaining magnetic characteristics such as loss and saturation magnetization at desired values. Also disclosed is a dust core using such a low magnetostriction body. Specifically disclosed is a low magnetostriction body obtained by shaping a soft magnetic material powder added with an organic compound having an effect of changing the magnetostriction of the soft magnetic material when combined with it, and heat-treating a green compact in an inert atmosphere. The absolute value of the magnetostriction ?O-P (1 T/50 Hz) of the low magnetostriction body is not more than 1.0×10?6. Also specifically disclosed is a dust core using such a low magnetostriction body.

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 plasma processing apparatus includes: a lift mechanism which, in a process vessel, moves down a stage to a standby position when plasma processing is not performed and moves up the stage to a processing position when the plasma processing is performed; a holding member detachably holding a mask which is to cover an outer peripheral edge portion of the substrate, between the standby position and the processing position; and a positioning mechanism positioning the mask on the stage, wherein: the mask is held while being horizontally movable without being positioned by the holding member; and when the stage is moved up from the standby position toward the processing position, the mask is transferred from the holding member onto the stage, and the mask is positioned on the stage by the positioning mechanism.

Abstract: An optical waveguide has a diffusion area (optical waveguide) with a high refractive index formed by diffusing impurities on a substrate. The diffusion area has a bent portion, and the optical waveguide includes: a groove formed by cutting the substrate along the diffusion area on the outside of the bent portion of the diffusion area; and a first buffer layer disposed on the upper portion of the diffusion area, having a refractive index equal to or higher than the refractive index of the substrate. The optical waveguide includes a second buffer layer having a refractive index equal to or lower than the refractive index of the substrate on the upper portion of the first buffer layer, and the second buffer layer is formed including contact with a side face of the groove.

Abstract: A reduction in size and cost of an optical modulator is achieved with a simple configuration, while improving the modulation characteristics. An optical modulator modulates light branched by an optical coupler and then couples the light via the optical coupler. The optical coupler is formed in a substrate having electro-optic effects. An optical waveguide is formed in the substrate and, includes a turnback section and ends into which the light branched by the optical coupler is input. A signal electrode is provided in the substrate along the optical waveguide. A modulation signal to modulate the light passing through the optical waveguide is input to the signal electrode.

Abstract: In an optical modulator according to the invention, with respect to two MZ type optical modulators connected to each other in tandem by a curved folded waveguide on an identical substrate, a longitudinal direction of an MZ type optical waveguide unit on an optical input port side is obliquely arranged to a longitudinal direction of an MZ type optical waveguide unit on an optical output port side, and a curvature radius of the curved folded waveguide is made larger than a half of an interval between the optical input/output ports to decrease a length of a feeder portion of a signal electrode corresponding to the MZ type optical waveguide unit on the input side. Therefore, a loss of an electric signal propagated through the signal electrode can be reduced.

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: An optical waveguide is formed by diffusing a second impurity to form a second diffusion area having a large refractive index on a substrate. A groove is formed at a portion of the substrate corresponding to an outside of a bend of a bent portion along the second diffusion area. A first diffusion area is formed by diffusing a first impurity from a bottom of the groove to reduce a refractive index of the substrate.

Abstract: An optical modulator includes a signal electrode for application of modulation signals whereby light propagated over an optical waveguide is modulated, and bias electrodes for application of a bias voltage for controlling an operating point for the modulation signals. A buffer layer is provided between a substrate exhibiting electro-optical effect and the bias electrodes, but at regions where no optical waveguide is formed beneath the bias electrodes, no buffer layer is provided, and the bias electrodes are provided directly upon the substrate. This configuration enables bias voltage to be reduced.

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: A microwave plasma processing system 10 includes: a processing chamber 100 in which a desired process is applied to a target object using a plasma; a susceptor 106 (stage) in the processing chamber 100 to support the target object; a high-frequency power supply 112 supplying high-frequency electric power to the susceptor 106; a capacitor 108a provided to the susceptor 106; and a measurement device 20 measuring voltages at the pair of plates of the capacitor 108a when high-frequency electric power is supplied from the high-frequency power supply 112 to the susceptor 106.

Abstract: An intake port for a 4-cycle engine includes an intake port base integrally formed with a cylinder head, and an intake port forming member that forms an intake port together with the intake port base. The area of the cross section of the intake port orthogonal to a centerline of the intake port is substantially uniform from an open intake side thereof toward a combustion chamber. The angle made by the centerline of the intake port and an intake valve shaft is larger than 90° from a viewpoint of the intake valve. Thereby, the 4-cycle engine can output high power with the intake port shape, as formed with above mentioned configuration, that reduces intake resistance and that uses simple design molds. More specifically, the engine can reliably prevent condensed fuel from remaining in the intake port to avoid incomplete combustion of gas.

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: In an optical modulator of the invention, a signal electrode and a ground electrode are formed along a pair of branching waveguides of a Mach-Zehnder type optical waveguide, and a first region positioned on an input side of an interaction section of light and an electric signal is made a forward modulation section, and a second region positioned on an output side is made an inverse modulation section, and a spacing or the like of the signal electrode and the ground electrode is optimized so that that a loss produced in the second region is relatively greater than a loss produced in the first region, with respect to a high frequency component of an electric signal propagated through the signal electrode. As a result a wider modulation bandwidth can be realized.

Abstract: An optical modulator of the Mach-Zehnder type including electrodes disposed above a substrate having a pair of linear portions of an optical waveguide includes a signal electrode to which modulating signals are applied; first and second earth electrodes; and a bias electrode to which a bias signal for controlling an operating point of the modulating signals is applied. The earth electrodes are disposed at either side of the signal electrode disposed above one of the linear portion, and the first earth electrode is disposed above the other linear portion. The bias electrode is disposed adjacent to the first earth electrode on a side opposite to the signal electrode. The bias electrode is disposed on a surface of the substrate, and a buffer layer is formed on the bias electrode. The first earth electrode has a ladder shape having the bias electrode interposed between the two long portions of the ladder.

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: A portable 4-cycle engine with a configuration which allows cooling air to flow in the direction of the crankshaft relative to a cylinder head on a cylinder, and a portable machine equipped with this engine, are provided, respectively. In such an engine, the cylinder is separated from the cylinder head including a combustion chamber formed at the cylinder side therein. The engine further comprises a valve train area formed in the cylinder head at the downwind side of the cooling air, and a plurality of vertical fins protruding upward from the cylinder head and extending in the direction of the crankshaft. The valve train area and the plurality of vertical fins are all integrally formed with the cylinder head, so that the cylinder head can be made thinner and lighter with high rigidity to enable the portable machine to become smaller, lighter, and more powerful.

Abstract: In an optical modulator according to the invention, with respect to two MZ type optical modulators connected to each other in tandem by a curved folded waveguide on an identical substrate, a longitudinal direction of an MZ type optical waveguide unit on an optical input port side is obliquely arranged to a longitudinal direction of an MZ type optical waveguide unit on an optical output port side, and a curvature radius of the curved folded waveguide is made larger than a half of an interval between the optical input/output ports to decrease a length of a feeder portion of a signal electrode corresponding to the MZ type optical waveguide unit on the input side. Therefore, a loss of an electric signal propagated through the signal electrode can be reduced.