Abstract: There is provided an optical waveguide device including: a substrate; an optical waveguide formed on the substrate; and a working electrode that controls a light wave propagating through the optical waveguide, in which the working electrode includes a first base layer made of a first material, a first conductive layer on the first base layer, a second base layer made of a second material different from the first material, which is on the first conductive layer, and a second conductive layer on the second base layer, and an edge of the second base layer is covered with the second conductive layer, in a cross-section perpendicular to an extending direction of the optical waveguide.

Abstract: Provided is an optical modulator that can be driven at lower voltage through the use of differential signal output. An optical modulator includes a substrate 1 and optical waveguides (21, 22) and a control electrode that are formed on the substrate, in which the optical waveguide includes Mach-Zehnder type optical waveguide, the control electrode is provided with two ground electrodes sandwiching three signal electrodes; the three signal electrodes are constituted by second and third signal electrodes that sandwich a first signal electrode, and have a wiring structure in which one modulation signal of the differential signal is applied to the first signal electrode, and the other modulation signal of the differential signal is applied to the second and third signal electrodes; and one branched waveguide (21) out of two Mach-Zehnder type optical waveguides is disposed between the first and second signal electrodes, and the other branched waveguide (22) is disposed between the first and third signal electrodes.

Abstract: Provided is an optical waveguide device in which both signal electrode collapse and signal electrode peeling/damage can be prevented.

Abstract: An optical waveguide element includes a substrate having an electro-optic effect, an optical waveguide formed in the substrate, and a control electrode arranged on the substrate to modulate a light wave propagating through the optical waveguide. The control electrode includes a signal electrode and a ground electrode. The signal electrode and the ground electrode are arranged along a modulation effect portion of the optical waveguide that performs modulation. In a shape of a bottom surface of the ground electrode facing the substrate, a slit separating the ground electrode into a first ground electrode close to the signal electrode and a second ground electrode far from the signal electrode is formed in a range corresponding to the modulation effect portion.

Abstract: There is provided an optical waveguide device including a substrate, an optical waveguide formed on the substrate, and a working electrode that controls a light wave propagating through the optical waveguide, in which the working electrode includes a first base layer made of a first material, and a first conductive layer on the first base layer, and a conductor pattern including a second base layer made of a second material different from the first material and a second conductive layer on the second base layer is formed in a region other than a path from an input end to an output end of the optical waveguide, in a region on the substrate.

Abstract: There is provided an optical waveguide device including: a substrate; an optical waveguide formed on the substrate; and a working electrode that controls a light wave propagating through the optical waveguide, in which the working electrode includes a first base layer made of a first material, a first conductive layer on the first base layer, a second base layer made of a second material different from the first material, which is on the first conductive layer, and a second conductive layer on the second base layer, and an edge of the second base layer is covered with the second conductive layer, in a cross-section perpendicular to an extending direction of the optical waveguide.

Abstract: An optical waveguide element including a substrate, an optical waveguide formed on the substrate, and an electrode for controlling a light wave propagating through the optical waveguide, in which the optical waveguide and the electrode have an intersection in which the optical waveguide and the electrode intersect with each other, and at the intersection, the electrode has a multilayer structure including a plurality of metal layers made of a metal material, and a resin layer made of a resin material is formed between the electrode and the substrate.

Abstract: Provided is an optical modulator that can be driven at lower voltage through the use of differential signal output. An optical modulator includes a substrate 1 and optical waveguides (21, 22) and a control electrode that are formed on the substrate, in which the optical waveguide includes Mach-Zehnder type optical waveguide, the control electrode is provided with two ground electrodes sandwiching three signal electrodes; the three signal electrodes are constituted by second and third signal electrodes that sandwich a first signal electrode, and have a wiring structure in which one modulation signal of the differential signal is applied to the first signal electrode, and the other modulation signal of the differential signal is applied to the second and third signal electrodes; and one branched waveguide (21) out of two Mach-Zehnder type optical waveguides is disposed between the first and second signal electrodes, and the other branched waveguide (22) is disposed between the first and third signal electrodes.

Abstract: In order to provide an optical modulator capable of preventing damage to the substrate and preventing deterioration of the properties of the modulator by reducing the stress on the substrate generated by the modulation electrode, there is provided an optical modulator 1, including: a substrate 5 having an electro-optic effect; an optical waveguide 10 formed on the substrate 5; and a modulation electrode (signal electrode S and ground electrode G) provided on the substrate 5 and modulating a light wave propagating in the optical waveguide 10, wherein a resin 8 to reduce the stress on the substrate 5 generated by the modulation electrode is arranged between a part of the bottom surface of the modulation electrode and the substrate 5 facing a part of the bottom surface of the modulation electrode.

Abstract: To provide an optical modulator in which a plurality of Mach-Zehnder type optical waveguides are integrated, which can be driven at a low voltage, and in which the occurrence of a crosstalk phenomenon is suppressed. Provided is an optical modulator including a substrate 1 having an electro-optic effect, and an optical waveguide 10 and a control electrode that are formed on the substrate, in which the optical waveguide has a structure in which a plurality of Mach-Zehnder type optical waveguides are disposed in parallel, the control electrode has a GSSG type differential electrode structure in which two signal electrodes S are disposed between two ground electrodes G for one of the Mach-Zehnder type optical waveguides, and a crosstalk suppressing unit that suppresses signal crosstalk is provided in the ground electrode sandwiched between adjacent Mach-Zehnder type optical waveguides, so that optical modulator can be driven at a low voltage, and in which the occurrence of a crosstalk phenomenon is suppressed.

Abstract: In an optical modulation element using a thinly processed substrate, cracking of the substrate during electrical connection is prevented, and poor connection or a reduction in manufacturing yield is prevented. An optical waveguide element includes an optical substrate on which an optical waveguide and a conductor pattern are formed, and a support substrate that supports the optical substrate, in which the conductor pattern includes at least one electrical connection area defined as a range in which electrical connection is performed, the optical substrate has a substrate removal portion in which a material of the optical substrate has been removed to penetrate through the optical substrate at a portion corresponding to the electrical connection area, and at least a part of the electrical connection area is formed on the support substrate via the substrate removal portion.

Abstract: An optical waveguide element including a substrate, an optical waveguide formed on the substrate, and an electrode for controlling a light wave propagating through the optical waveguide, in which the optical waveguide and the electrode have an intersection in which the optical waveguide and the electrode intersect with each other, and at the intersection, the electrode has a multilayer structure including a plurality of metal layers made of a metal material, and a resin layer made of a resin material is formed between the electrode and the substrate.

Abstract: In a waveguide-type optical modulation element that modulates light by applying radio frequency signals to an electrode, the realization of the additional broadening of the bandwidth by improving the degree of freedom in the design of the electrode is enabled. An optical modulation element, which includes optical waveguides provided in a substrate and electrodes that control light waves propagating through the optical waveguides and modulates light by propagating radio frequency signals to the electrodes, in which the electrodes include conductive layers made of copper or a copper alloy and protective layers made of a material other than copper and a copper alloy.

Abstract: In a light modulation element that modulates light by controlling light waves that propagate through an optical waveguide, the realization of the additional broadening of the bandwidth by improving the degree of freedom in the design of the electrode is enabled. A light modulation element which includes optical waveguides formed on a substrate and a control electrode and modulates light by controlling light waves that propagate through the optical waveguide by conducting electricity in the control electrode, in which the control electrode includes radio frequency electrodes that configure a signal line through which radio frequency signals propagate and a bias electrode to which a bias voltage is applied, and the radio frequency electrode has a conductive layer made of copper or a copper alloy.

Abstract: An optical waveguide element that has improved frequency response in a high frequency region is provided. An optical waveguide element includes: a substrate that has an electro-optic effect; an optical waveguide that is formed on the substrate; a control electrode that is for modulating light waves propagating through the optical waveguide; and a reinforcing substrate that holds the substrate via an adhesion layer, and the reinforcing substrate has a low-dielectric constant portion with a lower dielectric constant than that of the reinforcing substrate at least in a part of a region in a plan view of the reinforcing substrate such that the low-dielectric constant portion partitions the reinforcing substrate in a thickness direction.

Abstract: In a waveguide-type optical modulation element that modulates light by applying radio frequency signals to an electrode, the realization of the additional broadening of the bandwidth by improving the degree of freedom in the design of the electrode is enabled. An optical modulation element, which includes optical waveguides provided in a substrate and electrodes that control light waves propagating through the optical waveguides and modulates light by propagating radio frequency signals to the electrodes, in which the electrodes include conductive layers made of copper or a copper alloy and protective layers made of a material other than copper and a copper alloy.

Abstract: An optical modulator includes a substrate, an optical waveguide, a control electrode applying a high frequency signal in order to modulate light waves propagating through the optical waveguide, and a relay substrate provided with a relay line to transfer the high frequency signal to the control electrode. The control electrode and the relay line together have a coplanar line structure inclusive of at least electrical connection portions of both the control electrode and the relay line. The control electrode includes an electrical connection portion and a routing portion positioned between the electrical connection portion and an active portion applying an electrical field to the optical waveguide. The routing portion has a coplanar line structure. A distance between ground electrodes sandwiching a signal electrode in the electrical connection portion of the control electrode is substantially equal to a distance between ground electrodes sandwiching a signal electrode of the routing portion.

Abstract: An optical waveguide element that has improved frequency response in a high frequency region is provided. An optical waveguide element includes: a substrate that has an electro-optic effect; an optical waveguide that is formed on the substrate; a control electrode that is for modulating light waves propagating through the optical waveguide; and a reinforcing substrate that holds the substrate via an adhesion layer, and the reinforcing substrate has a low-dielectric constant portion with a lower dielectric constant than that of the reinforcing substrate at least in a part of a region in a plan view of the reinforcing substrate such that the low-dielectric constant portion partitions the reinforcing substrate in a thickness direction.

Abstract: An optical modulator includes a substrate, an optical waveguide, a control electrode applying a high frequency signal in order to modulate light waves propagating through the optical waveguide, and a relay substrate provided with a relay line to transfer the high frequency signal to the control electrode. The control electrode and the relay line together have a coplanar line structure inclusive of at least electrical connection portions of both the control electrode and the relay line. The control electrode includes an electrical connection portion and a routing portion positioned between the electrical connection portion and an active portion applying an electrical field to the optical waveguide. The routing portion has a coplanar line structure. A distance between ground electrodes sandwiching a signal electrode in the electrical connection portion of the control electrode is substantially equal to a distance between ground electrodes sandwiching a signal electrode of the routing portion.

Abstract: An optical device is provided, which includes: an optical waveguide provided in a substrate having an electro-optic effect; a signal electrode provided on the substrate and above the optical waveguide; and a peeling prevention film which is provided on at least a part of an outer peripheral portion of the substrate and at a position spaced apart from the signal electrode, and also serves as a ground electrode.