Matsushita Electric Industrial Co., Ltd.

Nuvoton Technology Corporation Japan

Masahiro Mitsuda

Tomoaki Uno

Tohru Nishikawa

Jun Ohya

Genji Tohmon

Yoshio Kishimoto

Akira Kimura

Yasuhiro Kobayashi

Kiyoshi Fujihara

Tsubasa Inoue

Yusuke Ito

Souichi Kimura

Takahiro Maeda

A semiconductor device includes: a transistor provided in a first region of a semiconductor layer in a plan view; a transistor provided in a second region adjacent to the first region of the semiconductor layer in the plan view; and a drain pad provided in a third region not overlapping the first region and the second region in the plan view. In the plan view, the first region and the second region are one region and an other region that divide an area of the semiconductor layer excluding the third region in half. In the plan view, the transistors are arranged in a first direction. The center of the third region is located on a straight center line that divides the semiconductor layer in half in the first direction and is orthogonal to the first direction. In the plan view, the drain pad is contained in the third region.

Semiconductor device

A planar optical waveguide includes a layered film formed on a substrate, and an optical waveguide core formed in the layered film. A cross section of the optical waveguide core is substantially quadrilateral, and a dopant layer including refractive index-lowering molecules is provided around the optical waveguide core. The refractive index-lowering molecules included in the dopant layer are unevenly distributed in the optical waveguide core with a concentration that is higher toward outer sides and corners of the optical waveguide core, whereby a graded-index optical waveguide is constituted.

Planar optical waveguide, method for manufacturing the same and polymer optical waveguide

The light-wave circuit module includes a substrate having a spot of substantially circular concave shape, an optically reflective film formed along an inner surface of the spot, and a planar optical waveguide passing through the spot. Light in the optical waveguide is reflected and focused obliquely upward by the optically reflective film in the spot.

Light-wave circuit module and method for manufacturing the same

An optical communications Module for use in an optical transfer system for bidirectionally transferring a light signal through an optical fiber, the optical communications module having a light signal transmission capability, wherein the optical communications module includes: a semiconductor laser; an optical fiber coupled to a front facet of the semiconductor laser; a light splitting element for splitting light which is emitted from the front facet of the semiconductor laser and propagated within the optical fiber; and, an output-monitoring photodiode for receiving a portion of the light which has been split by the light splitting element as monitoring light, and generating a photocurrent based on the monitoring light, the photocurrent being used for controlling optical output of the semiconductor laser.

Optical communications module and method for mounting optical communications module

The optical transmitter/receiver apparatus of the invention includes: an optical fiber for transmitting/receiving an optical signal therethrough; and a first base including mutually spaced optical signal transmitting and receiving regions and a fiber end supporting region located between the optical signal transmitting and receiving regions. A semiconductor laser device for emitting the optical signal to be transmitted is secured to the optical signal transmitting region of the first base. A fiber end supporting portion for supporting one end of the optical fiber, to which the optical signal emitted from the semiconductor laser device is incident, is formed in the fiber end supporting region of the first base. A second base for supporting the body of the optical fiber is secured to the optical signal receiving region of the first base. A reflective filter for transmitting the optical signal to be transmitted, emitted from the semiconductor laser device, and for reflecting the optical signal to be received, incident through the other end of the optical fiber, is supported by being inserted into the second base and the body of the optical fiber. A light-receiving device for receiving the optical signal to be received, reflected by the reflective filter, is secured to the second base.

Optical transmitter/receiver apparatus, method for fabricating the same and optical semiconductor module

A bidirectional optical semiconductor apparatus of the present invention includes: a substrate embedding an optical waveguide, through which output light and input light are propagated; a semiconductor light-emitting device for emitting the output light toward one end of the optical waveguide; an optical branching filter, provided in the optical waveguide, for transmitting at least part of the output light and guiding at least part of the input light to the outside of the optical waveguide; a semiconductor light-receiving device, provided over the substrate, for receiving the input light guided by the optical branching filter to the outside of the optical waveguide; and a light-blocking member, formed on the surface of the semiconductor light-receiving device, for blocking the light emitted from the semiconductor light-emitting device.

Bidirectional optical semiconductor apparatus

The optical device of the present invention includes a substrate, at least one first groove formed on the substrate, an optical fiber placed in the first groove, and at least one second groove diagonally formed across the optical fiber. Furthermore, the optical device includes an optical member inserted in the second groove, having a surface which reflects or diffracts at least a part of light propagating through the optical fiber. A photodetector is placed at a position where light which is reflected or diffracted by the optical member is received. As a result, an miniaturized optical device having a low loss and high reliability can be provided at low cost.

Optical device and method for producing the same

A semiconductor light-receiving device comprises a substrate, an optical fiber, a semiconductor light-receiving element, an optical member, and holders. A groove for a buried optical fiber is formed in the main surface of the substrate to extend from one end of the substrate to the other end thereof. The optical fiber is buried in the optical fiber groove and covered with a resin material. The semiconductor light-receiving element has a light-receiving portion at a surface thereof in opposing relation to the main surface of the substrate and is disposed on the main surface of the substrate via bumps such that the light-receiving portion is opposed to the optical fiber. The optical member is disposed in the substrate in an intersecting relationship with the optical fiber to reflect or diffract signal light propagated through the optical fiber and irradiate the light-receiving portion of the semiconductor light-receiving element with the reflected or diffracted signal light. The holders are provided in the substrate to suppress a temperature-dependent variation in the width of the optical fiber groove.

Semiconductor light-receiving device, method of manufacturing the same, bidirectional optical semiconductor device, and optical transmission system

EA bidirectional optical semiconductor apparatus of the present invention includes: a substrate embedding an optical waveguide, through which output light and input light are propagated; a semiconductor light-emitting device for emitting the output light toward one end of the optical waveguide; an optical branching filter, provided in the optical waveguide, for transmitting at least part of the output light and guiding at least part of the input light to the outside of the optical waveguide; a semiconductor light-receiving device, provided over the substrate, for receiving the input light guided by the optical branching filter to the outside of the optical waveguide; and a light-blocking member, formed on the surface of the semiconductor light-receiving device, for blocking the light emitted from the semiconductor light-emitting device.

An active layer of a semiconductor laser element held by a laser mount is formed to be closer to the bottom than to the center of the height of the semiconductor laser element. A laser beam emitted from the active layer passes through a collective lens and an optical isolator and enters an incidence portion of an optical fiber. Returning light reflected by the incidence portion of the optical fiber passes through the optical isolator and the collective lens and is collected onto an end face of the laser mount. The optical isolator includes first and second rutiles which transmit normal light with refraction and abnormal light without refraction, a Faraday element which rotates a polarization plane of transmitted light in the clockwise direction by 45 degrees, and a permanent magnet for applying a magnetic field to the Faraday element.

Semiconductor laser module, optical fiber amplifier and optical transfer

The optical fiber amplifier of this invention includes plural pump light sources for emitting pump light; a first wavelength multiplexer for receiving the pump light emitted by the pump light sources at plural input ports and wavelength multiplexing the received pump light, so as to generate wavelength multiplexed pump light and output the wavelength multiplexed pump light from an output port; a second wavelength multiplexer for receiving the wavelength multiplexed pump light at a first input port and receiving signal light at a second input port, so as to generate coupled light by coupling the wavelength multiplexed pump light and the signal light and emit the coupled light from an output port; and a rare earth-doped optical fiber for receiving the coupled light emitted from the output port of the second wavelength multiplexer and amplifying the coupled light. At least one of the pump light sources is a narrow-linewidth light source for emitting light with a laser linewidth of approximately 5 nm or less as the pump light.

Optical fiber amplifier, semiconductor laser module for pumping and

The fiber amplifier of this invention includes: a first rare earth element doped fiber; a second rare earth element doped fiber; and a pump light source for generating pump light for exciting the first rare earth element doped fiber and the second rare earth element doped fiber, the fiber amplifier receiving analog signal light and amplifying the analog signal light, wherein the fiber amplifier further includes a directional transmitter disposed between the first rare earth element doped fiber and the second rare earth element doped fiber, and a transmittance of the directional transmitter for at least light having the same wavelength as the signal light propagating from the first rare earth element doped fiber to the second rare earth element doped fiber is larger than a transmittance of the directional transmitter for the light propagating from the second rare earth element doped fiber to the first rare earth element doped fiber.

Intermediate isolator type fiber amplifier and fiber transmission system

The erbium-doped fiber amplifier comprises: a first erbium-doped optical fiber pumped by 0.98 .mu.m band light and amplifying the signal light; a first pump light source for producing the 0.98 .mu.m band light; a first optical coupler for coupling the 0.98 .mu.m band light with the signal light at an input portion of the first optical fiber; a second erbium-doped optical fiber pumped by 1.48 .mu.m band light and amplifying the signal light; a second pump light source for producing the 1.48 .mu.m band light; and a second optical coupler for coupling the 1.48 .mu.m band light with the signal light at an output portion of the second optical fiber; wherein a pump light isolator is installed between the first optical fiber and the second optical fiber for blocking the passing of the 1.48 .mu.m band light from the second optical fiber to the first optical fiber while allowing the passing of the signal light.

Growing community of inventors

Kyoto, Japan

Masahiro Mitsuda