Nippon Telegraph and Telephone Corporation

Ntt Electronics Corporation

Japan Science and Technology Agency

Yusuke Nasu

Yuichiro Ikuma

Takashi Yamada

Shunichi Soma

Toshikazu Hashimoto

Hiroshi Takahashi

Ryoichi Kasahara

Yohei Sakamaki

Yuriko Kawamura

Kuninori Hattori

Manabu Oguma

Kiyofumi Kikuchi

Ikuo Ogawa

Shogo Yamanaka

Fumihiro Ebisawa

Takayuki Mizuno

Kenya Suzuki

Ken Tsuzuki

Yasuyuki Inoue

Takashi Saida

Kotaro Takeda

Makoto Jizodo

Keiichi Morita

Hiroki Kawashiri

Shinji Yamashita

Yuichi Suzuki

Atsushi Aratake

Shinji Mino

Yosuke Takeuchi

Takashi Goh

Hiroto Kawakami

Hiroshi Terui

Fumito Nakajima

Yasuaki Hashizume

Shigeo Nagashima

Atsushi Murasawa

Kazumasa Yoshida

Teruaki Sato

Akira Komiyama

Yoshiteru Jinnouchi

Takashi Nakayama

Toshiyuki Ozawa

Atsushi Tomita

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 (EP) 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.

Optical module

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.

Optical circuit module

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 μm.

Optical fiber connection structure

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.

Optical circuit with common ground configuration for resistors and thermo-optic phase shifters

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.

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.

Light reception element and light shielding structure for optical circuit

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.

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 (θ) formed between the first surface and each of the connection waveguides is the same as an angle (φ) formed between the second surface and each of the connection waveguides.

Interposer circuit

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.

Optical 90 degree hybrid circuit

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.

Photodetector

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. When blocking a transmission optical signal, the voltage amplitude of a transmission electrical signal to be applied to the quadrature modulator is adjusted such that it is smaller than a half-wave voltage, at most two dither signals are applied to the first phase modulation units, a component output by the light receiving element, the component having n times a frequency of the dither signals, is detected, and bias voltages to be applied to the first phase modulation units are controlled such that the component having n times the frequency is minimized.

Optical transmitter and method for controller optical transmitter

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.

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.

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. The polarization multiplexing optical transmitting and receiving circuit includes an optical variable branching circuit that branches the light output from the light source, a light fixing symmetric branching circuit connected to one of outputs of the optical variable branching circuit and a light fixing asymmetric branching circuit connected to the other, optical receivers connected to two outputs of the light fixing symmetric branching circuit, respectively, optical transmitters connected to two outputs of the light fixing asymmetric branching circuit, a polarized wave rotator connected to one of the optical transmitters, and a polarized wave multiplexer that polarization-multiplexes the outputs of the optical transmitters.

Polarization multi/demultiplexed optical transceiver circuit

A polarization multiplex optical transmitter circuit can provide compensation for the transmission PDL while reducing decrease in transmission power. The polarization multiplex optical transmitter circuit includes a beam divider circuit configured to divide light outputted from a light source, optical phase shifters provided in at least one of two waveguides connected to output terminals of the beam divider circuit, a light wave synthesizer circuit connected to the two waveguides, first and second optical transmitters coupled to two output terminals of the light wave synthesizer circuit, a polarization multiplexer configured to synthesize two output polarized waves from the first and second optical transmitters, and a polarization rotator provided between the first and second optical transmitters and the polarization multiplexer and coupled to at least one of the first and second optical transmitters.

Growing community of inventors

Atsugi, Japan

Yusuke Nasu