Hitachi, Ltd.

Youngkun Lee

Shinichi Saito

Katsuya Oda

Makoto Miura

Toshio Katsuyama

Yasunobu Matsuoka

Tatsuya Tomaru

Kazuhiko Hosomi

A parallel optical module includes a light-emitting or light-receiving element arrayplaced on a substrate, an optical connectoroptically connecting the optical element arrayand an external optical fiber array, the optical connectorhaving a shape of at least an octahedron which is bilaterally symmetrical about the center of the outer shape thereof viewed along the optical axis direction, and an engaging memberplaced on the same substrateas the substrate on which the optical element arrayis mounted, the engaging member having a groove onto which the optical connectoris fitted. A side wall of the groove of the engaging memberhas an inclination corresponding to, among each surface of the optical connector, a second surfaceadjacent to a first surfacefacing the optical element arrayin the direction perpendicular to the substrate.

Optical module and transmitting device

A semiconductor photodiode includes a semiconductor substrate; a first conduction type first semiconductor layer formed above the semiconductor substrate; a high resistance second semiconductor layer formed above the first semiconductor layer; a first conduction type third semiconductor layer formed above the second semiconductor layer; and a second conduction type fourth semiconductor layer buried in the second semiconductor layer, in which the fourth semiconductor layer is separated at a predetermined distance in a direction horizontal to the surface of the semiconductor substrate.

Semiconductor photodiode device and manufacturing method thereof

A semiconductor photodiode device includes a semiconductor substrate, a first buffer layer containing a material different from that of the semiconductor substrate in a portion thereof, a first semiconductor layer formed above the buffer layer and having a lattice constant different from that of the semiconductor substrate, a second buffer layer formed above the first semiconductor layer and containing an element identical with that of the first semiconductor layer in a portion thereof, and a second semiconductor layer formed above the buffer layer in which a portion of the first semiconductor layer is formed of a plurality of island shape portions each surrounded with an insulating film, and the second buffer layer allows adjacent islands of the first semiconductor layer to coalesce with each other and is in contact with the insulating film.

The invention provides an optical waveguide for enabling the reduction of a coupling loss caused by difference in the size of a mode field diameter between optical waveguide modes different in the mode field diameter and a coupling loss caused by reflection on a boundary caused by the difference of media and an optical device using it. Structure provided with a mode field diameter converter provided with an antireflection part required to reduce a coupling loss between a microoptical circuit and a single mode optical fiber is integrally produced using effective refractive index control based upon photonic crystal structure.

Optical waveguides and optical devices with optical waveguides

A semiconductor optical amplifier module comprises: a demultiplexer made of a semiconductor material to separate an optical input signal containing a plurality of wavelength components into a plurality of demultiplexed signals, each of the demultiplexed signals having a different one of the wavelength component; a plurality of semiconductor optical amplifiers each optically coupled to the demultiplexer to amplify a corresponding one of the demultiplexed signals; and a multiplexer made of the semiconductor material and optically coupled to the plurality of semiconductor optical amplifiers to combine the demultiplexed signals amplified by the semiconductor optical amplifiers to produce a multiplexed signal. The demultiplexer, the semiconductor amplifiers and the multiplexer are integrated on a single semiconductor substrate. The demultiplexer and the multiplexer may be implemented by arrayed waveguide diffraction grating structures, and the semiconductor optical amplifiers may be implemented by a semiconductor quantum well structure having well widths ranging from a minimum value to a maximum value. The semiconductor optical amplifiers can provide a gain wavelength bandwidth of 80-800 nm.

Broad band semiconductor optical amplifier module having optical amplifiers for amplifying demutiplexed signals of different wavelengths and optical communication system using it

Growing community of inventors

Hachioji, Japan

Youngkun Lee