Abstract: An optical modulator that suppresses poor welding between a case main body and a lid portion is provided.

Abstract: An optical modulator with which electrical connection between a signal electrode and signal wiring of a wiring substrate can be reliably made even in a case where a width of the signal electrode in an action portion of an optical control substrate is narrow is provided.

Abstract: An optical device includes a housing that accommodates at least an optical waveguide element, a main body portion 1 of the housing having an opening portion OP on one surface and a lead pin PN1 fixed to a side surface adjacent to the one surface, and including a metal member 2 disposed to surround the opening portion OP and a lid member 11 that closes the opening portion OP and is joined to the metal member 2, in which end portions of the metal member 2 and the lid member 11 along the side surface of the main body portion 1 at which the lead pin PN1 is disposed are located on an inner side of the main body portion 1 than the side surface of the main body portion 1.

Abstract: An optical waveguide device includes a substrate on which an optical waveguide is formed, and a reinforcing block disposed on the substrate, along an end surface of the substrate on which an input portion or an output portion of the optical waveguide is disposed, in which an optical component that is joined to both the end surface of the substrate and an end surface of the reinforcing block is provided, a material used for a joining surface of the optical component and a material used for the substrate or the reinforcing block have at least different linear expansion coefficients of a direction parallel to the joining surface, and an area of the joining surface is set to be smaller than a maximum value of a total of areas of cross sections of the substrate and the reinforcing block parallel to the joining surface.

Abstract: An optical waveguide device includes a substrate on which an optical waveguide is formed, and a reinforcing block disposed on the substrate, along an end surface of the substrate on which an input portion or an output portion of the optical waveguide is disposed, in which an optical component that is joined to both the end surface of the substrate and an end surface of the reinforcing block is provided, a material used for a joining surface of the optical component and a material used for the substrate or the reinforcing block have at least different linear expansion coefficients of a direction parallel to the joining surface, and an area of a joining portion of the optical component is set to be smaller than an area of the end surfaces including joining portions of the substrate and the reinforcing block.

Abstract: An optical waveguide element includes an optical waveguide which is formed on one surface of a substrate, an incidence part for light to be incident on the optical waveguide or an emission part for emitting light from the optical waveguide which is disposed in an end portion of the substrate, and a dielectric film which is formed on the optical waveguide of at least one of the incidence part and the emission part, and the vicinity thereof. Regarding the dielectric film, dielectric films including a dielectric film formed of a first material having an index of refraction higher than an index of refraction of the substrate and a dielectric film formed of a second material having an index of refraction lower than the index of refraction of the substrate are alternately laminated.

Abstract: An optical waveguide device includes a substrate on which an optical waveguide is formed, and a reinforcing block disposed on the substrate, along an end surface of the substrate on which an input portion or an output portion of the optical waveguide is disposed, in which an optical component that is joined to both the end surface of the substrate and an end surface of the reinforcing block is provided, a material used for a joining surface of the optical component and a material used for the substrate or the reinforcing block have at least different linear expansion coefficients of a direction parallel to the joining surface, and an area of a joining portion of the optical component is set to be smaller than an area of the end surfaces including joining portions of the substrate and the reinforcing block.

Abstract: An optical waveguide device includes a substrate on which an optical waveguide is formed, and a reinforcing block disposed on the substrate, along an end surface of the substrate on which an input portion or an output portion of the optical waveguide is disposed, in which an optical component that is joined to both the end surface of the substrate and an end surface of the reinforcing block is provided, a material used for a joining surface of the optical component and a material used for the substrate or the reinforcing block have at least different linear expansion coefficients of a direction parallel to the joining surface, and an area of the joining surface is set to be smaller than a maximum value of a total of areas of cross sections of the substrate and the reinforcing block parallel to the joining surface.

Abstract: An optical waveguide device module includes an optical waveguide device and a connection substrate provided outside the optical waveguide device, and these are housed in a housing. The optical waveguide device has a control electrode including a signal electrode and ground electrodes disposed to interpose the signal electrode between the ground electrodes. A signal line, ground lines disposed so as to interpose the signal line between the ground lines, and a back surface ground electrode disposed on a surface of the connection substrate are provided on the connection substrate. The ground line and the back surface ground electrode are electrically connected through a via hole passing through the connection substrate. Electrical connection means for electrically connecting the ground line and the ground electrode is provided. A connection portion of the electrical connection means on the ground line side is in the vicinity of the via hole of the ground line.

Abstract: An optical waveguide element includes an optical waveguide which is formed on one surface of a substrate, an incidence part for light to be incident on the optical waveguide or an emission part for emitting light from the optical waveguide which is disposed in an end portion of the substrate, and a dielectric film which is formed on the optical waveguide of at least one of the incidence part and the emission part, and the vicinity thereof. Regarding the dielectric film, dielectric films including a dielectric film formed of a first material having an index of refraction higher than an index of refraction of the substrate and a dielectric film formed of a second material having an index of refraction lower than the index of refraction of the substrate are alternately laminated.

Abstract: An optical control element including an optical waveguide formed by using diffusion of titanium that is formed on a lithium niobate substrate and a control electrode formed on the lithium niobate substrate that is provided in the vicinity of the optical waveguide, in which an amount of a hydroxyl group absorbed into the lithium niobate substrate is set to be in a range of 0.5 to 2.5 cm?1.

Abstract: An optical waveguide device module includes an optical waveguide device and a connection substrate provided outside the optical waveguide device, and these are housed in a housing. The optical waveguide device has a control electrode including a signal electrode and ground electrodes disposed to interpose the signal electrode between the ground electrodes. A signal line, ground lines disposed so as to interpose the signal line between the ground lines, and a back surface ground electrode disposed on a surface of the connection substrate are provided on the connection substrate. The ground line and the back surface ground electrode are electrically connected through a via hole passing through the connection substrate. Electrical connection means for electrically connecting the ground line and the ground electrode is provided. A connection portion of the electrical connection means on the ground line side is in the vicinity of the via hole of the ground line.

Abstract: An optical control element including an optical waveguide formed by using diffusion of titanium that is formed on a lithium niobate substrate and a control electrode formed on the lithium niobate substrate that is provided in the vicinity of the optical waveguide, in which an amount of a hydroxyl group absorbed into the lithium niobate substrate is set to be in a range of 0.5 to 2.5 cm?1.

Abstract: An optical modulator is provided which can compensate for a bias shift between an output light and a monitoring light of the optical modulator and which has a configuration capable of being reduced in size with a simple structure. The optical modulator comprises a substrate that has an electro-optical effect, an optical waveguide that includes a Mach-Zehnder type optical waveguide formed in the substrate, a modulation electrode that modulates light waves propagating in the optical waveguide, an optical fiber that guides an output light from the optical waveguide, light collecting means for collecting two radiated lights from the Mach-Zehnder type optical waveguide toward a single optical receiving element, and light intensity ratio adjusting means for adjusting a light intensity ratio of the two radiated lights received by the optical receiving element.

Abstract: An optical modulator is provided which can compensate for a bias shift between an output light and a monitoring light of the optical modulator and which has a configuration capable of being reduced in size with a simple structure. The optical modulator comprises a substrate that has an electro-optical effect, an optical waveguide that includes a Mach-Zehnder type optical waveguide formed in the substrate, a modulation electrode that modulates light waves propagating in the optical waveguide, an optical fiber that guides an output light from the optical waveguide, light collecting means for collecting two radiated lights from the Mach-Zehnder type optical waveguide toward a single optical receiving element, and light intensity ratio adjusting means for adjusting a light intensity ratio of the two radiated lights received by the optical receiving element.