Fujikura Limited

Hitachi, Ltd.

Agency for Science, Technology and Research

Bussan Nanotech Research Institute, Inc.

Other

Hitachi Vlsi Engineering Corp.

Lumentum Japan, Inc.

Bussan Nanotech Research, Inc.

Kensuke Ogawa

Kazuhiro Goi

Hiroyuki Kusaka

Ning Guan

Ken Sakuma

Toshio Katsuyama

Akira Oka

Guo-Qiang Patrick Lo

Tadashi Fukuzawa

Hiroaki Inoue

Toshiyuki Usagawa

Hiroshi Kakibayashi

Ryokichi Matsumoto

Kenji Hiruma

Mingbin Yu

Gerard P Morgan

Yong Tsong Tan

Hwee Gee Teo

Hisataka Sugiyama

Hirofumi Sukeda

Akira Arimoto

Hidetoshi Matsumoto

Toshiaki Masuhara

Takeshi Nakao

Koji Ishida

Toshiyuki Aida

Ken Yamaguchi

Masanari Koguchi

Akira Suzuki

Shigehisa Tanaka

Xiaoguang Tu

Shinichi Wakabayashi

Tsung-Yang Liow

Hitoshi Uemura

Hiroki Irie

Mitsuru Fujii

Takayoshi Fukui

Kenji Oda

Masamitsu Yazawa

Hiroki Ishihara

Nobutaka Futigami

Keiichi Haraguchi

Masamits Yazawa

Masashi Kawasaki

Yong-Tsong Tan

An electro-optic waveguide device may include a slot waveguide including a lower high-refractive-index layer with a first refractive index and an upper high-refractive-index layer with a second refractive index, wherein the lower high-refractive-index layer and the upper high-refractive-index layer have conductivity and are disposed to face each other with a gap; and a slot part formed as a low-refractive-index layer, wherein the low-refractive-index layer is formed of a material producing an electro-optic effect and has a third refractive index lower than the first refractive index and the second refractive index, wherein the low-refractive-index layer is formed in the gap to come into contact with the lower high-refractive-index layer and the upper high-refractive-index layer, and wherein one of the lower high-refractive-index layer or the upper high-refractive-index layer includes a stretch stretching on both sides of a contact portion with the slot part in a width direction intersecting a transmission direction.

Electro-optic waveguide device and optical module

Provided is an optical waveguide element having a reduced optical loss, a lower driving voltage, and a reduced size. A rib waveguide core of an optical waveguide includes a first core region and a second core region which constitute a PN junction and which are provided so as to overlap each other in a horizontal direction. A depletion layer is formed between the first core region and the second core region. The depletion layer extends from a rib region to both of two slab regions. The depletion layer is located so as to be vertically lower in the slab regions than in the rib region.

Optical waveguide element

An optical receiver circuit includes: a substrate; and an optical waveguide device that is formed on the substrate. The optical waveguide device includes: a first optical splitter section branching the signal light into a first signal light propagation waveguide and a second signal light propagation waveguide and; a second optical splitter section branching the local-oscillator light into a first local-oscillator light propagation waveguide and a second local-oscillator light propagation waveguide; a first optical coupler section that combines the signal light propagating through the first signal light propagation waveguide and the local-oscillator light propagating through the first local-oscillator light propagation waveguide with each other; a second optical coupler section that combines the signal light propagating through the second signal light propagation waveguide and the local-oscillator light propagating through the second local-oscillator light propagation waveguide with each other.

Optical receiver circuit and adjustment method for same

To reduce the optical loss, lower the driving voltage, produce a smaller product, and simplify the production process, an embodiment of the present invention includes a rib waveguide core () having a rib region () and two slab regions (), where a depletion layer () is so formed as to extend from the rib region () to the two slab regions ().

An optical waveguide device includes a substrate; a lower cladding disposed on the substrate; a rib waveguide including a slab disposed on the lower cladding and a single rib disposed on the slab contiguous to the slab; and an upper cladding disposed on the rib waveguide. The rib waveguide includes a first doped region having a first electric conductivity exhibiting a P-type electric conductivity across the rib and the slab and a second doped region being contiguous to the first doped region and having a second electric conductivity exhibiting an N-type electric conductivity across the rib and the slab.

Optical waveguide device and method of manufacturing the same

An optical waveguide device includes: a mode splitter including a main waveguide in which lights can be propagated in at least two propagation modes with different propagation orders and a subsidiary waveguide which includes a coupling section disposed in parallel with the main waveguide at a certain distance away from the main waveguide so as to constitute a directional coupler and is capable of splitting at least one propagation mode out of the two or more propagation modes from the main waveguide. Also, n/nwhich is a refractive index ratio between a core and a cladding which constitute the main waveguide and the subsidiary waveguide is in a range of 101% to 250%.

Optical waveguide device having a light absorber for split out modes

An optical waveguide element includes a core and a cladding that is made of SiO. When nis a group refractive index of a TEpolarized wave in the i-th waveguide counted from a light incidence plane of the core and nis a group refractive index of a TMpolarized wave in the i-th waveguide, the length L[m] of the i-th waveguide satisfies a predetermined relation.

Optical waveguide element, light-receiving device, optical communication device, optical modulator, optical resonator, and method for manufacturing optical waveguide element

An optical modulation device configured of a planar optical waveguide, includes: a light incidence unit which allows light to be incident on the planar optical waveguide; a Mach-Zehnder interferometer which includes a first optical splitter section branching the light incident on the light incidence unit, two arm portions guiding the light branched by the first optical splitter section, a phase modulation unit linearly disposed on each of the two arm portions, and a first optical coupler section combining the light guided from the two arm portions; a light launching unit which launches the light combined by the first optical coupler section from the planar optical waveguide; and a traveling-wave electrode which includes an input unit and an output unit, and applies a voltage to the phase modulation unit.

Optical modulation device

An optical integrated circuit includes: a mode conversion and branching section that launches light from a first optical waveguide to a second optical waveguide, converts light from the first optical waveguide into converted light, and launches the converted light to a third optical waveguide; an optical multiplexing and branching section that multiplexes lights from the second and third optical waveguides into one multiplexed light component, and branches the multiplexed light component into a light component to be input to a fourth optical waveguide and a light component to be input to a fifth optical waveguide; a phase modulation section that is provided in at least one of the fourth and fifth optical waveguides and modulates a phase of guided light; and an optical multiplexing section that multiplexes light components from the fourth and fifth optical waveguides into one light component.

Optical integrated circuit

A high-order polarization conversion device configured of a planar optical waveguide, includes: a substrate; a lower clad disposed on the substrate; a core including a lower core and an upper core, the lower core being disposed on the lower clad and having a fixed height in a rectangular sectional shape, the upper core being formed of the same material as the lower core and having a fixed height in a rectangular sectional shape that is disposed continuously on the lower core; and an upper clad that is disposed on the core and the lower clad and is formed of the same material as the lower clad. The high-order polarization conversion device performs high-order polarization conversion between TEof the start portion and TMof the end portion.

High-order polarization conversion device, optical waveguide device, and DP-QPSK modulator

A polarization conversion element is disclosed in which an optical waveguide formed on a substrate sequentially includes a first waveguide portion, a polarization rotation portion, and a second waveguide portion, an effective refractive index of a TE mode having the highest effective refractive index in an eigen mode of waveguide light on a sectional surface of the first waveguide portion is higher than an effective refractive index of a TM mode having the highest effective refractive index, an effective refractive index of the TM mode having the highest effective refractive index on a sectional surface of the second waveguide portion is higher than an effective refractive index of the TE mode having the highest effective refractive index, and heights of waveguide structures (for example, cores) of the first waveguide portion and the second waveguide portion are equal to each other.

Polarization conversion element

An optical waveguide element includes: a rib waveguide and a pair of slab portions including a first slab portion and a second slab portion connected to both sides of the rib portion so as to sandwich the rib portion. The rib portion has a cross-sectional dimension which allows the propagation of a fundamental mode and a higher order mode in a predetermined single polarization state, and has a first P-type semiconductor and a first N-type semiconductor forming a PN junction, the first slab portion has a second P-type semiconductor and a P-type conductor connected to each other, the second P-type semiconductor is connected to the first P-type semiconductor of the rib portion, the second slab portion has a second N-type semiconductor and an N-type conductor connected to each other, and the second N-type semiconductor is connected to the first N-type semiconductor of the rib portion.

Optical waveguide element and optical modulator

A planar optical waveguide device, includes: two input portions that are waveguides that have the same width, are parallel to each other, and have rectangular cross-sections; a wide portion that is a linear waveguide and is connected after the two input portions; a tapered portion that is connected after the wide portion and that is a multi-mode waveguide which has a tapered shape having a width decreasing gradually and through which at least TE1 propagates; and an output portion that is connected after the tapered portion and that is a multi-mode waveguide which has a rectangular cross-section and through which at least TE1 propagates. The planar optical waveguide device forms a high-order mode conversion combining element that outputs the TE0, which is input to the two input portions, as the TE1 from the output portion.

Planar optical waveguide device and DP-QPSK modulator

Provided is an optical element including an optical waveguide including a core formed from: a rib part; and a first and second slab parts sandwiching the rib part. The first slab part includes a P-type region, the second slab part includes an N-type region, the rib part includes a P-type region which is in contact with the P-type region provided in the first slab part, and an N-type region which is in contact with the N-type region provided in the second slab part. The rib part includes a top portion which is located above the first and second slab parts and includes an undoped region formed from at least one of an intrinsic region and a low-concentration doping region which is doped at a dopant concentration 1/10 or less of a dopant concentration in at least one of the adjacent P-type region and the adjacent N-type region.

Optical element and Mach-Zehnder optical waveguide element

A polarization conversion device includes: a directional coupler that includes an input side optical waveguide and an output side optical waveguide which are disposed in parallel to each other and each of which has a core. Assuming that a direction in which the input side optical waveguide and the output side optical waveguide face each other is a width direction and a direction perpendicular to the width direction is a height direction in a cross section perpendicular to a longitudinal direction of each of the input side optical waveguide and the output side optical waveguide, and the directional coupler is configured to couple first light guided through the input side optical waveguide to second light guided through the output side optical waveguide, the polarization direction of the second light is perpendicular to that of the first light.

Polarization conversion device

Growing community of inventors

Sakura, Japan

Kensuke Ogawa