The Furukawa Electric Co., Ltd.

Yasumasa Kawakita

Hitoshi Shimizu

Takeo Kageyama

Norihiro Iwai

Keishi Takaki

Yasutaka Higa

Kazuaki Kiyota

Hirotatsu Ishii

Naoki Tsukiji

Toshihito Suzuki

Suguru Imai

Akihiko Kasukawa

Masaki Funabashi

Noriyuki Yokouchi

Takuya Ishikawa

Masayuki Iwami

Tatsuro Kurobe

Eisaku Kaji

Kageyama Takeo

Takeyoshi Matsuda

Hitoshzi Shimizu

Peter Nyakas

An optical functional device includes: first and second optical couplers each including a multi-mode interferometer waveguide portion having a first end portion and a second end portion, two units of first input/output ports and two units of second input/output ports; and first and second arc-shaped waveguides each optically connecting one of the first and second input/output ports of the first and second optical coupler and one of the first and second input/output ports of the second optical coupler, respectively. Further, the first optical coupler, the second optical coupler, the first arc-shaped waveguide, and the second arc-shaped waveguide constitute a ring resonator, and each of the multi-mode waveguide portions of the first optical coupler and the second optical coupler have a narrow portion, an average width of the narrow portion in a longitudinal direction being narrower than widths at the first end portion and the second end portion.

Optical functional device and laser device

A reflection filter device includes: a ring resonator filter including a ring-shaped waveguide and two arms, each of the two arms being optically coupled to the ring-shaped waveguide; and a dual-branch portion including a light input/output port and two branch ports, the light input/output port being configured to allow input and output of light, the two branch ports being configured to allow output of the light input from the light input/output port, the light being split into two, the two arms being connected to the two branch ports, respectively, at least one of the two arms being equipped with a phase adjuster.

Reflection filter device and wavelength-tunable laser device

An optical waveguide structure includes a lower cladding layer positioned on a substrate; an optical guide layer positioned on the lower cladding layer; an upper cladding layer positioned on the optical guide layer; and a heater positioned on the upper cladding layer. The lower cladding layer, the optical guide layer, and the upper cladding layer constitute a mesa structure. The optical guide layer has a lower thermal conductivity than the upper cladding layer. An equation 'W&#x2264;W&#x2264;3&#xd7;W' is satisfied, wherein Wrepresents a mesa width of the mesa structure, and Wrepresents a width of the optical guide layer. The optical guide layer occupies one-third or more of the mesa width in a width direction of the mesa structure.

Optical waveguide structure

A laser device includes a wavelength-tunable laser including plural wavelength selectors in an optical resonator; a semiconductor optical amplifier that amplifies the laser light input thereto; a light intensity variation detector that detects variation in intensity of the laser light output from the wavelength-tunable laser before the laser light is input to the semiconductor optical amplifier; a wavelength dithering generation unit that generates a resonator mode wavelength dithering to modulate a resonator mode of the resonator; a wavelength dithering feedback controller that performs, on the resonator mode wavelength dithering, feedback control based on the variation in intensity detected by the light intensity variation detector; a light intensity detector that detects an intensity of the laser light output from the semiconductor optical amplifier; and a semiconductor optical amplifier feedback controller that performs feedback control on the semiconductor optical amplifier based on the intensity detected by the light intensity detector.

Wavelength-tunable laser device

A semiconductor laser device is a vernier-type wavelength-tunable semiconductor laser device including an optical resonator, constituted by first and second reflective elements having reflection comb spectra in which reflection peaks are arranged on a wavelength axis in a substantially periodic manner and having mutually different periods. At least one of the first and second reflective elements has a sampled grating structure having a reflection comb spectrum in which reflection phases at the respective reflection peaks are aligned and the intensity of a reflection peak outside a set laser emission wavelength bandwidth is lower than the intensity of a reflection peak within the laser emission wavelength bandwidth.

Semiconductor laser device, diffraction grating structure, and diffraction grating

A wavelength tunable laser device includes: a laser cavity formed of a grating and a reflecting mirror including a ring resonator filter; a gain portion; and a phase adjusting portion. The grating creates a first comb-shaped reflection spectrum. The ring resonator filter includes a ring-shaped waveguide and two arms and creates a second comb-shaped reflection spectrum having peaks of a narrower full width than peaks in the first comb-shaped reflection spectrum at a wavelength interval different from that of the first comb-shaped reflection spectrum. One of the peaks in the first comb-shaped reflection spectrum and one of the peaks in the second comb-shaped reflection spectrum are overlapped on a wavelength axis, and a spacing between cavity modes is narrower than the full width at half maximum of the peaks in the first comb-shaped reflection spectrum.

Wavelength tunable laser device and laser module

A semiconductor device includes a semiconductor layer formed of a III-V group semiconductor crystal containing As as a primary component of a V group. A V group element other than As has been introduced at a concentration of 0.02 to 5% into a V group site of the III-V group semiconductor crystal in the semiconductor layer.

Semiconductor device

A semiconductor optical device includes an active layer, the active layer including a plurality of quantum well layers having gain peak wavelengths different from one another in a layering direction thereof, and a plurality of barrier layers, wherein the quantum well layers and the barrier layers are alternately layered over each other, and an n-type dopant has been added in the plurality of quantum well layers having gain peak wavelengths different from one another and in the plurality of barrier layers.

Semiconductor optical device

Provided is a laser device comprising a substrate, an active layer, and a current confinement layer. The current confinement layer includes an oxide layer that is formed extending from a edge of the current confinement layer in a parallel plane parallel to a surface of the substrate, toward a center of the current confinement layer along the parallel plane, and that does not have an inflection point between the edge and a tip portion formed closer to the center or has a plurality of inflection points formed between the edge and the tip portion.

Laser device, method of manufacturing the same, laser device array, light source and light module

Provided is a vertical light emitting device comprising an upper multilayer reflective film and a lower multilayer reflective film that are formed facing each other and oscillate light; an intermediate layer that is formed below the upper multilayer reflective film and includes a layer having a different composition than the upper multilayer reflective film; and an electrode portion that is formed to sandwich the intermediate layer in a cross-sectional plane parallel to an oscillation direction of the light and to have a top end that is higher than a top surface of the intermediate layer. After the electrode portion is formed to sandwich the intermediate layer, the upper multilayer reflective film is layered on the intermediate layer.

Vertical light emitting device and manufacturing method

A surface emitting laser includes lower and upper multilayer mirrors, first-conductivity-type and second-conductivity-type contact layers formed between the lower and the upper multilayer mirrors, an active layer formed between the first-conductivity-type and the second-conductivity-type contact layers, a current confinement layer formed between the second-conductivity-type contact layer and the active layer, and first and second composition gradient layers formed facing each other across the current confinement layer. The first composition gradient layer and the second composition gradient layer are formed such that bandgap energy of each of the layers is monotonically decreased from the current confinement layer to an adjacent layer and approach bandgap energy of the adjacent layer in a growth direction.

Surface emitting laser, light source, and optical module

An electronic device comprising a multilayer semiconductor structure formed by a periodic structure having a first semiconductor layer and a second semiconductor layer, wherein in at least a portion of the multilayer semiconductor structure, the first semiconductor layer and the second semiconductor layer have different conduction types. The first semiconductor layer and the second semiconductor layer have different refractive indexes, and the multilayer semiconductor structure functions as a multilayer reflective mirror. As a result, an electronic device, a surface emitting laser, a surface emitting laser array, a light source, and an optical module with decreased parasitic capacitance can be realized.

Electronic device, surface emitting laser, surface emitting laser array, light source, optical module

Included are: an active layer provided between an upper multilayer film reflecting mirror and a lower multilayer film reflecting mirror formed on a GaAs substrate and formed of a periodic structure of a low-refractive-index layer formed of AlGaAs (0.8&#x2266;x&#x2266;1) and a high-refractive-index layer formed of AlGaAs (0&#x2266;y&#x2266;x), at least one of the low-refractive-index layer and the high-refractive-index layer being of n-type; and a lower electrode provided between the lower multilayer film reflecting mirror and the active layer and configured to inject an electric current into the active layer.

Vertical cavity surface emitting laser element, vertical cavity surface emitting laser array element, vertical cavity surface emitting laser device, light source device, and optical module

There is provided an optical interconnection system including a plurality of semiconductor integrated devices each including a surface emitting laser array device including a plurality of surface emitting laser devices each emitting an output laser signal light of a different wavelength modulated based on an input modulated signal, a silicon optical waveguide that guides output laser signal lights emitted from the surface emitting laser devices of each of the semiconductor integrated devices to another semiconductor integrated device, a plurality of optical couplers respectively corresponding to the semiconductor integrated devices and guiding the output laser signal lights to the silicon optical waveguide, and a plurality of optical splitters respectively corresponding to the semiconductor integrated devices, receiving the output laser signal lights guided by the silicon optical waveguide, and inputting an input laser signal light to a corresponding one of the semiconductor integrated devices.

Growing community of inventors

Tokyo, Japan

Yasumasa Kawakita