Abstract: The present invention is intended to provide an inspection optical circuit that can input and output inspection light to and from a circuit to be inspected with low loss, and can minimize a space for disposing the inspection optical circuit. Provided is an inspection optical circuit for inspecting a tested circuit formed on an optical circuit chip on a wafer by inputting and outputting light through a grating coupler, wherein the grating coupler is formed on the same optical circuit chip as the tested circuit, and a folded waveguide for connecting an input/output waveguide of the tested circuit and the grating coupler is formed in a region provided on a dicing line for cutting out the optical circuit chip.

Abstract: An optical module is provided with a columnar protrusion over the entire pickup area (EP) for automatic suction by a mounting device at the center of the upper surface of a fiber holding carrier. The protrusion secures a dedicated pickup area (EP1) on a top surface. When an extra length of an optical fiber extending from an optical device is routed and held between a pair of wall portions, the extra length including a tip portion is held in a storage area of the fiber holding carrier by a restoring force caused by being pressed against the wall portions.

Abstract: An optical circuit module in which an optical fiber array and an optical circuit substrate are connected, the optical fiber array including a groove substrate in which a groove for optical fiber alignment is formed, a pressing plate stacked on and bonded to the groove substrate, and an optical fiber bonded to and fixed in the groove of the groove substrate, and the optical circuit substrate including an input/output waveguide. In a connection surface of the optical circuit module, an area of a common portion in a cross section of the optical circuit substrate and the pressing plate is larger than an area of a common portion in a cross section of the optical circuit substrate and the groove substrate.

Abstract: An optical module according to the present invention includes: an optical device including an optical waveguide chip; an optical fiber block bonded to and arranged on an end face of the optical waveguide chip; an optical fiber that has one end optically connected to the optical waveguide chip via the optical fiber block; an optical fiber holding mechanism for holding the other end of the optical fiber; and an optical fiber carrier. The optical fiber is arranged while being curved from the optical fiber carrier toward the optical fiber block in a U-shape, and a wall structure is formed on the surface of the carrier while being adjacent to the optical fiber at, for example, a position on the outer side of the U-shaped curve of the optical fiber position at which the wall structure reduces a normal force of the optical fiber.

Abstract: An optical fiber array includes a V-groove substrate in which a V-groove for optical fiber alignment is formed, a pressing plate laminated and bonded on the V-groove substrate, and an optical fiber bonded and fixed in the V-groove of the V-groove substrate, wherein a distance between the optical fiber and the V-groove is less than 20 ?m.

Abstract: An optical circuit of the present disclosure shares at least a part of an electrical path including phase variable means between neighboring optical interference circuits, or configures an electrical path so as to straddle neighboring optical interference circuits, thereby performing electrical or thermal feedback. The optical circuit includes a mechanism using the electrical or thermal feedback for cancelling components of thermal crosstalk from one optical interference circuit to another neighboring optical interference circuit. The optical circuit of the present disclosure has a resistor element that shares electrical paths including respective phase variable means between the neighboring optical interference circuits. The optical circuit changes the phase change amount by the phase variable means in the neighboring optical interference circuit, in such a way as to cancel the thermal crosstalk components by the resistor element.

Abstract: In a pipe structure in which an optical fiber passes, miniaturization of the optical module in the longitudinal direction of the optical fiber is prevented. In the optical module according to the present invention, a holding structure of the optical fiber necessary to adopt the pipe structure is moved to a cover extension unit of the package. The optical fiber is adhered and fixed to the cover extension unit protruding from the cover body unit of the package to ensure protection of the optical fiber, and the optical waveguide chip is disposed to be closer to an inner wall of a side surface of the package. By disposing the optical waveguide chip to be close to the inner wall of the package as much as possible and reducing the mounting area in the package to the utmost, it is possible to realize miniaturization of the entire optical module.

Abstract: A light shielding structure of an optical circuit of the present invention uses a part of the structure of the light reception element itself to suppress stray light. A stepped electrode that covers an upper surface and side surface of a first semiconductor layer constituting a light absorption portion of the light reception element is formed at a height substantially equal to that of an optical waveguide in the optical circuit, and the light absorption portion of the light reception element is shielded from stray light by a wall-shaped or column-shaped wiring electrode extending substantially perpendicularly to a surface layer of the optical circuit. The light shielding structure of the present invention uses a part of the configuration of the light reception element, is formed integrally with the light reception element, and also has an aspect of the invention of the light reception element.

Abstract: An optical module according to the present invention includes: an optical device including an optical waveguide chip; an optical fiber block bonded to and arranged on an end face of the optical waveguide chip; an optical fiber that has one end optically connected to the optical waveguide chip via the optical fiber block; an optical fiber holding mechanism for holding the other end of the optical fiber; and an optical fiber carrier. The optical fiber is arranged while being curved from the optical fiber carrier toward the optical fiber block in a U-shape, and a wall structure is formed on the surface of the carrier while being adjacent to the optical fiber at, for example, a position on the outer side of the U-shaped curve of the optical fiber position at which the wall structure reduces a normal force of the optical fiber.

Abstract: To provide an optical 90-degree hybrid formed of a silicon waveguide capable of suppressing an optical loss and a phase error, and facilitating electronic packaging and optical packaging. In the optical 90-degree hybrid circuit including two optical branching units facing each other and two optical coupling units facing away from each other, four arm waveguides are arranged including bent waveguides each of which guides an output light of the optical branching unit to the optical coupling unit, and is formed in a curved shape.

Abstract: An object is to improve crosstalk between ports while keeping an interposer circuit small. In an interposer circuit that includes a first surface connected to an optical circuit, a second surface that is connected to a fiber block and is located opposite to the first surface in parallel with the first surface, and a plurality of connection waveguides connected to a plurality of input/output waveguides included in the optical circuit and a plurality of input/output fibers included in the fiber block, the connection waveguides each have a straight shape, and an angle (?) formed between the first surface and each of the connection waveguides is the same as an angle (?) formed between the second surface and each of the connection waveguides.

Abstract: A photodetector is realized which does not need an additional circuit for an inspection and may perform a characteristic evaluation inspection of optical input and electrical output such as optical sensitivity and OE characteristics of a photodetector alone with respect to wavelength and temperature dependent characteristics. A photodetector is provided in which light absorption layers are formed on a semiconductor substrate, the photodetector detects signal light incident on the light absorption layers from a direction in a substrate surface of the semiconductor substrate, and the light absorption layers have a portion not covered by an electrode for photocurrent detection connected with the light absorption layers in a case where the substrate surface of the semiconductor substrate is seen from a direction from an outside of the substrate surface.

Abstract: An optical module is provided with a columnar protrusion over the entire pickup area (EP) for automatic suction by a mounting device at the center of the upper surface of a fiber holding carrier. The protrusion secures a dedicated pickup area (EP1) on a top surface. When an extra length of an optical fiber extending from an optical device is routed and held between a pair of wall portions, the extra length including a tip portion is held in a storage area of the fiber holding carrier by a restoring force caused by being pressed against the wall portions. In this holding state, since the tip portion of the extra length can be disposed along the outer periphery of the protrusion, even in a case where the position where the optical fiber is held is slightly shifted by a shock from outside.

Abstract: An optical transmitter includes quadrature modulators and light receiving elements to which inverted output light of output light from the quadrature modulators is input, the quadrature modulators including parent Mach-Zehnder modulators in respective paths of a first pair of paths into which carrier light from a light source is split, the parent Mach-Zehnder modulators including child Mach-Zehnder modulators including first phase modulation units, and second phase modulation units.

Abstract: An object is to easily convey by suction an optical module equipped with optical fibers having ends coupled to optical receptacles and mount the optical module on a substrate. An optical module according to the present invention includes an optical device to which optical fibers having ends coupled to optical receptacles are optically coupled and also includes a carrier composed of a substrate and adhesive layers formed on the upper and lower surfaces of the substrate. The optical device is bonded on the adhesive layer formed on the lower surface of the substrate. Part of the optical fibers and the optical receptacles are bonded on the adhesive layer formed on the surface of the substrate.

Abstract: An optical module with optical fibers is intended to be able to be easily sucked and conveyed, and mounted on another substrate. An optical module of the present disclosure includes an optical device to which optical fibers are optically connected; and a carrier including a substrate and an adhesive layer formed at a surface of the substrate, and a part of the optical device and a part of the optical fibers are adhesively fixed on a surface of the adhesive layer. The optical device may include ball grid array shaped electrodes. The carrier may be provided with a plurality of holes.

Abstract: An optical fiber array includes a V-groove substrate in which a V-groove for optical fiber alignment is formed, a pressing plate laminated and bonded on the V-groove substrate, and an optical fiber bonded and fixed in the V-groove of the V-groove substrate, wherein a distance between the optical fiber and the V-groove is less than 20 ?m.

Abstract: An optical circuit module in which an optical fiber array and an optical circuit substrate are connected, the optical fiber array including a groove substrate in which a groove for optical fiber alignment is formed, a pressing plate stacked on and bonded to the groove substrate, and an optical fiber bonded to and fixed in the groove of the groove substrate, and the optical circuit substrate including an input/output waveguide. In a connection surface of the optical circuit module, an area of a common portion in a cross section of the optical circuit substrate and the pressing plate is larger than an area of a common portion in a cross section of the optical circuit substrate and the groove substrate.

Abstract: A light shielding structure of an optical circuit of the present invention uses a part of the structure of the light reception element itself to suppress stray light. A stepped electrode that covers an upper surface and side surface of a first semiconductor layer constituting a light absorption portion of the light reception element is formed at a height substantially equal to that of an optical waveguide in the optical circuit, and the light absorption portion of the light reception element is shielded from stray light by a wall-shaped or column-shaped wiring electrode extending substantially perpendicularly to a surface layer of the optical circuit. The light shielding structure of the present invention uses a part of the configuration of the light reception element, is formed integrally with the light reception element, and also has an aspect of the invention of the light reception element.

Abstract: Provided is a polarization multiplexing optical transmitting and receiving circuit that compensates for transmission side PDL so as to suppress a reduction in transmission power and makes a branching ratio of light from a light source variable between a transmission side and a receiving side according to a system to be used.