Hitachi, Ltd.

Oclaro Japan, Inc.

Hitachi Cable, Inc.

Opnext Japan, Inc.

Lumentum Japan, Inc.

Hiroaki Inoue

Hiroyoshi Matsumura

Koji Ishida

Hitoshi Nakamura

Toshio Katsuyama

Kazuhisa Uomi

Shinji Sakano

Hirohisa Sano

Shigehisa Tanaka

Takanori Suzuki

Naoki Chinone

Tadashi Fukuzawa

Kensuke Ogawa

Hiroyasu Sasaki

Hideaki Takano

Mitsuo Akashi

Kohichi Robert Tamura

Shinji Nishimura

Akira Arimoto

Toshihisa Tsukada

Kimio Tatsuno

Masahiro Ojima

Shinji Tsuji

Kouji Nakahara

Masaki Ohira

Makoto Suzuki

Shigeki Kitajima

Kenji Hiruma

Misuzu Sagawa

Tatsuo Kanetake

Hiroki Irie

Kunio Tada

Hiroyuki Kamiyama

Shoichi Hanatani

Takayoshi Fukui

Toshio Kirihara

Hiroyoshi Matumura

Yoshitaka Okada

Masaru Mukaikubo

Mari Ogawa

Hideaki Tsushima

Chiyuki Kitahara

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

In an optical transmitter module for combining three or more optical signals different in intensity with an optical multiplexer to generate a PAM signal, the influence of the beat noise and the chromatic dispersion due to the difference in wavelength is reduced. The optical transmitter module includes first through third optical signal sources adapted to output respective optical signals binary intensity modulated with different amplitude from each other, and a combining section. The combining section has a wavelength multiplexer adapted to wavelength-multiplex a plurality of input optical signals having different wavelengths from each other while keeping the respective polarization states, and a polarization multiplexer adapted to polarization-multiplex a pair of input optical signals having respective polarization states perpendicular to each other, and the combining section combines the input optical signals from the first through third optical signal sources with each other to generate a PAM8 signal.

Optical transmitter module

An optical module includes a semiconductor optical device in which an active layer located at one side, an electrode located at the same side, and a mirror that reflects light toward the side opposite the electrode are monolithically integrated, a sub-mount having one surface on which a first wiring pattern is formed, a substrate in which an optical waveguide and a grating coupler are formed in a surface layer of the substrate, a spacer having an upper surface on which a second wiring pattern is formed, and a wire. The sub-mount is mounted on the spacer. The first wiring pattern on the sub-mount faces part of the second wiring pattern on the spacer and is electrically connected thereto. The second wiring pattern on the spacer includes a pad being disposed in a region exposed from the sub-mount and being bonded to the wire.

Optical module

Some semiconductor lasers have an initial failure mode that is advanced as the amount of optical power therein, namely, the amount of optical output observed from the outside increases in almost independent of the temperature. The initial failure mode that is advanced as the amount of optical output increases is not sufficiently screened, so that the initial failure rate is somewhat higher than that of the semiconductor laser having the conventional active layer material. It is effective to introduce a test with large optical output at lower temperature than average operating temperature such as room temperature, during the manufacturing process. This helps to eliminate elements having the initial failure mode that is advanced as the amount optical output increases, thereby to extend the expected life of the laser diodes.

Method of manufacturing semiconductor laser for communication, semiconductor laser for communication and optical transmission module

An optical switch has an input optical waveguide and an output optical waveguide that are physically and optically separated from each other by a two-level crossing arrangement. The direction of optical signal propagation is switchable by a connecting optical waveguide to provide optical coupling between the input and output optical waveguides. Crosstalk and loss due to diffraction at each crossing are small, and insertion loss does not increase, even for a large-scale application.

Optical switch having a two-level crossing between input/output optical

To obtain an optical functional device such that the reflectivity of a facet and the loss of coupling with a fiber are reduced, a mode conversion region for changing the beam spot size is formed on the input facet and/or the output facet in an optical function region and the facet of the side to be connected with a fiber in the mode conversion region is formed obliquely to the direction of propagation of light.

Semiconductor optical functional device

In an optical demultiplexing system comprising a plurality of optical demultiplexers for separating the component optical signals respectively having predetermined wavelengths of an input wavelength-multiplexed optical signal, a first optical amplifier is connected to the input of the optical demultiplexer disposed at the input end of the optical demultiplexing system, and a plurality of optical amplifiers are disposed to amplify the output optical signal of the first optical amplifier before the S/N ratio of the optical signal is caused to fall by optical losses caused within the optical demultiplexing system below a predetermined S/N ratio guaranteeing a predetermined bit error rate.

Optical demultiplexing system with optical amplifiers

There is provided a self-routing optical switch array formed by connecting m stages of optical switches and set so as to satisfy the relation:

Self-routing optical switch and optical switch array

A semiconductor optical switch and an optical switch array for use in an optical logic circuit, photonic switching, OEIC, etc., wherein a light amplifying means is provided on a bypass waveguide that connects a plurality of optical waveguides, thereby enabling improvement of the light crosstalk and the light propagation loss. In particular, according to the arrangement of the present invention that a light amplifying means is provided in addition to the deflecting portion, no noise component is amplified and therefore the SN ratio is markedly increased.

Semiconductor optical switch and array of the same

An optical modulator includes two cladding layers of different conductive types, a light absorption layer formed between the cladding layers for propagating incident light and for absorbing the light in response to a voltage applied between the cladding layers, and an optical waveguide layer formed between the cladding layers and optically connected to the light absorption layer, for propagating the light.

Optical modulator and optical communication system utilizing the same

A semiconductor optical device and an optical device array is provided which can be used in an optical logic circuit, photonic switching OEIC, etc. The device includes a light amplifying arrangement provided on a bypass waveguide that connects a plurality of optical waveguides, thereby enabling improvement of the light crosstalk and the light propagation loss. In particular, by virtue of providing a light amplifying means in addition to the light deflecting portion, noise components are not amplified, and, therefore, the SN ratio is markedly increased.

Semiconductor optical device and array of the same

A semiconductor laser device comprises a semiconductor laser which oscillates a fundamental wave, and a transparent waveguide which is installed substantially in parallel to a direction of a cavity of the semiconductor laser and integral with the semiconductor laser, where second harmonics of the fundamental wave travel through the transparent waveguide and are emitted therefrom. The semiconductor laser and the transparent waveguide have a refractive index in a prescribed range respectively, and an output of second harmonics being significantly high in comparison to the prior art can be obtained.

Semiconductor laser device having a transparent waveguide and a large

A semiconductor optical device and an optical device array is provided which can be used in an optical logic circuit, photonic switching OEIB, etc. The device includes a light amplifying arrangement provided on a bypass wavelength that connects a plurality of optical waveguides, thereby enabling improvement of the light crosstalk and the light propagation loss. In particular, by virtue of providing a light amplifying means in addition to the light deflecting portion, noise components are not amplified, and, therefore, the SN radio is markedly increased.

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Saitama, Japan

Hiroaki Inoue