Fujikura Limited

Kabushiki Kaisha Toshiba

The Furukawa Electric Co., Ltd.

Hiroyuki Kusaka

Kensuke Ogawa

Kazuhiro Goi

Akira Oka

Masahiro Kashiwagi

Kentaro Tomioka

Toshiyuki Tanaka

Mitsuyoshi Tanimoto

Ryokichi Matsumoto

Aage Granaas

Satoshi Saito

Kazuhiro Watanabe

Toshiyuki Hirota

Katsumi Hisano

Takashi Shigematsu

Tomonao Takamatsu

Hiroyuki Hotta

Yukihiko Hata

Akihiro Murakami

Hitoshi Uemura

Shinji Ichikawa

Teruo Kinoshita

Kenji Oda

Yuichiro Kunai

Hiroki Ishihara

Shingo Nishijima

Haruo Sakuma

Koji Kuromiya

An optical amplification apparatus includes a first amplification optical fiber, a second amplification optical fiber, a first pumping light source, and a second pumping light source. The first amplification optical fiber includes a first core and a first cladding layer. The first core is doped with an active element using a first active element doping concentration distribution. The first cladding layer is disposed out of the first core and has a refractive index lower than the refractive index of the first core. The second amplification optical fiber is connected to the first amplification optical fiber in a longitudinal direction of the first amplification optical fiber. The second amplification optical fiber includes a second core and a second cladding layer. The second core is doped with active element using a second active element doping concentration distribution that is different from the first active element doping concentration distribution.

Optical amplification apparatus

An optical computing system includes: a light diffraction element group including n pieces of light diffraction elements, where n is a natural number of 2 or more. Each of the n pieces includes cells, each of which has a thickness or a refractive index that is independently set. Each of the cells is classified into a C1 cell or a C2 cell. The thickness or the refractive index of each of the C1 cells is set such that optical computing that is carried out by the light diffraction element group becomes an identity operation when the C2 cells are masked.

Optical computing system

An optical computing device includes: one or more light-diffraction elements each of which includes microcells, wherein each of the microcells has an individually set thickness or refractive index; and an optical signal input section that simultaneously inputs an optical signal and a delayed optical signal obtained by delaying the optical signal to the one or more light-diffraction elements.

Optical arithmetic device

An imaging device includes: an optical computing section that receives a first optical signal and generates a second optical signal including a feature amount extracted from the first optical signal; an image sensor that converts the second optical signal into a first electric signal including a piece of image information; and a computer that receives the first electric signal and generates second electric signals using machine learning models, each of the second electric signals corresponding to a respective one of the machine learning models, wherein: each of the second electric signals, generated from the first electric signal including the same piece of image information, includes different image information.

Imaging device, imaging method, and method for producing the imaging device

A light diffraction element, that has cells, includes first regions and second regions. Each of the cells comprises one of the first regions and one of the second regions. Each of the first regions has a thickness or a refractive index that is independently set. The second regions have a uniform thickness or a uniform refractive index. The first regions allow first polarized components of signal light to pass through. The second regions allow second polarized components of signal light to pass through. The second polarized components are different, in polarization direction, from the first polarized components. The light diffraction element performs optical computing by causing the first polarized components of signal light that have passed through the first regions to interfere with each other. The first polarized components of signal light output from the light diffraction element indicate information after the optical computing.

Light diffraction element and optical computing system

A fiber laser apparatus includes a pump light source that emits pump light; a pump delivery fiber that guides the pump light; an amplifying optical fiber that is optically coupled to the pump delivery fiber and guides laser light; and a filter element that causes more loss of light of a wavelength range that includes a peak wavelength of at least one of Stokes light and anti-Stokes light than the laser light. The Stokes light and anti-Stokes light result from four-wave mixing involving a plurality of guide modes in a multi-mode fiber that guides the laser light. The filter element is disposed between: the pump delivery fiber and the amplifying optical fiber, the amplifying optical fiber and the multi-mode fiber, or at the multi-mode fiber.

Filter element, laser device, fiber laser device, filter method, and method for manufacturing laser device

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

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

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

Disclosed is a method of producing an insulated electric wire, in which a primary coating layer including at least an enamel-baking layer is formed on a metallic conductor to form a primary coated electric wire, and a secondary coating layer is extrusion-formed on the primary coating layer of the primary coated electric wire. The method includes an electric wire pre-heating process where a surface of the primary coating layer is pre-heated using an electric wire pre-heating unit, and a resin extrusion process where a secondary coating layer is extrusion-formed on the pre-heated primary coating layer using a resin extrusion unit. Further disclosed is an apparatus for producing an insulated electric wire.

Growing community of inventors

Sakura, Japan

Hiroyuki Kusaka