Abstract: Provided is a device for monitoring that realizes monitoring of an influence of thermal stress on a phase of an optical circuit on a surface where an optical circuit is formed. The device for monitoring according to the present disclosure is a device for monitoring for monitoring an influence of thermal stress on a phase of an optical circuit during mounting or actual operation on an optical module manufactured by a bare chip mounting method, wherein the device for monitoring includes a substrate and a plurality of stress sensitive circuits formed on the substrate, and wherein the device for monitoring is arranged on a surface of the optical module on which the optical circuit is formed, and monitors the influence of thermal stress on a phase of the optical circuit on the basis of either signal light propagating through the optical circuit or external light input from the outside.

Abstract: An inspection pattern capable of performing wafer-level automatic inspection using a cantilever-type probe card is provided. An inspection pattern according to one embodiment of the present disclosure includes: a Cu pillar pad formed on a semiconductor substrate; a Cu pillar formed on the Cu pillar pad; and an inspection pad formed on the semiconductor substrate, electrically coupled adjacent to or proximate to the Cu pillar pad, and configured to provide a region that a cantilever-type probe comes in contact with during wafer-level automatic inspection.

Abstract: An optical waveguide of the present disclosure proposes a configuration of a bent waveguide having a novel configuration. For proposed four types of curves A, B, C, and D, a value obtained by differentiating a curvature along a waveguide is 0 at one end 1=0 and the other end 1=L of a bent waveguide. It is possible to suppress optical loss and inter-mode crosstalk occurring in the bent waveguide. Even in a bent waveguide having a waveguide width under a multimode condition, excellent inter-mode crosstalk characteristics and low loss are achieved as compared with the clothoid curve of the prior art.

Abstract: A photo detector includes a first cladding layer, a first semiconductor layer of a first conductivity type on the first cladding layer, a light absorption layer on the first semiconductor layer, a second semiconductor layer of a second conductivity type on the light absorption layer, a second cladding layer on the first semiconductor layer, the second cladding layer covering the light absorption layer and the second semiconductor layer, and a plurality of columnar vias penetrating the second cladding layer and connected with the second semiconductor layer, where the plurality of columnar vias are arranged in an arrangement direction parallel to a surface of the first semiconductor layer on which the light absorption layer is disposed, and a coverage factor in plan view of each of the plurality of columnar vias decreases from a first end side to a second end side in the arrangement direction of the light absorption layer.

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 transmission/reception module includes an optical chip including a light transmission device and a light receiving device, a transmission analog IC, a reception analog IC, a signal processing LSI, a level conversion circuit that converts an intensity monitor signal output from a driver circuit into a level compatible with a gain control signal of a transimpedance amplifier, a switch provided between an intensity monitor terminal of the driver circuit and an input terminal of the level conversion circuit, and a switch provided between an output terminal of the level conversion circuit and a gain control terminal of the transimpedance amplifier.

Abstract: An inspection circuit that accurately reflects influence of a manufacturing error generated in a modulator of a main circuit in manufacturing process of an optical circuit, and at the same time, achieves downsizing, is disclosed. The inspection circuit includes an inspection waveguide having a length of half of a length of an arm waveguide of the main circuit and is configured such that test light propagates in two directions on the inspection waveguide, thereby implementing reproduction of characteristics equivalent to those of the modulator of the main circuit. In order to propagate the test light in two directions of the inspection waveguide in the inspection circuit, a loop-shaped path configured between branch ports of the optical branches is utilized. Embodiments of different configurations are disclosed in accordance with aspects where two branch light beams of the test light are guided to the inspection waveguide.

Abstract: Provided is an optical device having a long lifetime and high reliability. An optical device according to one embodiment comprises at least one Mach-Zehnder (MZ) modulator and a redundant semiconductor optical amplifier (SOA). The redundant SOA is connected to at least one MZ modulator via a 2-input 2-output coupler. The redundant SOA includes two SOAs arranged in parallel, and the two SOAs are arranged in two waveguides connected to the 2-input 2-output coupler, respectively. The redundant SOA is configured to switch the two SOAs to amplify light modulated by the at least one MZ modulator or light obtained before modulation.

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.