Fujitsu Corporation

Fujisu Limited

Kaoru Moriya

Takayuki Masuko

Shinya Inagaki

Akira Okamoto

Keiko Takeda

Norio Suzuki

Yasushi Sugaya

Hiroshi Onaka

Norifumi Shukunami

Tomoaki Takeyama

Manabu Watanabe

Keiko Sasaki

Tadao Arima

Hisashi Takamatsu

Koji Okamura

Kenji Tagawa

Takashi Satou

Hideki Isono

Hiroki Okushima

Saburo Uno

Gan Oda

Eiji Kikuchi

Masayuki Siga

Makoto Fujihara

Nobuyoshi Horigome

An optical dropping apparatus and an optical add/drop multiplexer capable of dropping optical signals of an arbitrary wavelength from a WDM optical signal. The apparatus comprises a generating means for occurring four-wave mixing, a dropping means for dropping light of a predetermined wavelength, and a controlling means for controlling the wavelength of a pump light which is occurred four-wave mixing at the generating means. This apparatus is able to change the wavelength of the optical signals to be dropped, by changing the wavelength of the pump light.

Optical dropping apparatus and optical add/drop multiplexer

A signal light passes through an isolator, and is coupled by a coupler with a pump light from a pump light source. Then, the signal light passes through an ASE reflection filter, is amplified by an EDF, and is transmitted from an isolator. At this time, an ASE light having a predetermined wavelength among ASE lights that occur within the EDF and proceed to the ASE reflection filter is reflected and again input to the EDF. By setting the predetermined wavelength to a wavelength on the short wavelength side of an amplification band of the EDF, gain deviation occurring on the long wavelength side of the amplification band can be cancelled.

Optical fiber amplifier

An optical amplifier which suppresses the occurrence of a nonlinear optical phenomena, such as four-wave mixing. The optical amplifier includes an optical fiber doped with a rare earth element, and a light source providing excitation light to the fiber so that a wavelength division multiplexed (WDM) light is amplified as the WDM light travels through the fiber from a first point to a second point along the fiber. A third point exists along the fiber between the first and second points at which a power of the WDM light substantially reaches a level producing a nonlinear optical phenomenal. A first portion of the fiber is between the first point and the third point, and a second portion of the fiber is between the third point and the second point. The second portion suppresses the occurrence of the nonlinear optical phenomena as compared to the first portion. The second portion can have various different constructions to provide the required suppression effect.

Optical fiber amplifier using optical fiber having a portion which suppresses nonlinear optical phenomena

An optical waveguide device which can be connected with an optical fiber through a simple positioning adjustment. The optical waveguide device comprises a substrate, a first cladding with a uniform thickness formed on the substrate, a core formed on the first cladding, a recognizable thin layer formed on the first cladding on both sides of the core, and a second cladding formed on the first cladding so as to cover the core. The thin layer is parallel to the top surface of the substrate and defines a reference plane which is substantially in the same plane as the bottom surface of the core. Connection of the optical waveguide device with the optical fiber is achieved by bringing the reference plane into contact with a plane which is in a predetermined relative position to the optical fiber and only making a planar positioning adjustment with the planes held in contact.

Optical waveguide device and method for connecting optical waveguide and

A photodetector carrier is disclosed which does not cause possible deterioration of an optical coupling characteristic between an optical fiber and a photodetector mounted on the carrier and is improved in high speed characteristics of the photodetector. The photodetector carrier is constructed by brazing to a metal plate of a ceramic substrate on which a photodetector mounting portion and a wiring pattern are formed. The photodetector carrier is fixed to a metal casing of a photodetector module by laser welding.

Photodetector carrier for improving the high speed of a photodetector

Semiconductor laser module and positioning method thereof

A photodetector module comprising an optical fiber and a photodetector which are coupled by direct optical coupling is disclosed. A photodetector chip is fixedly attached to the circular top surface, having the shape of a circle circumscribed around the photodetector chip, of a carrier having the shape of a frustum of a circular cone, or the photodetector chip is fixedly attached to the circular bottom surface, having the shape of a circle circumscribed around the photodetector chip, of a circular recess formed in the bottom of a taper recess formed in the carrier and having the shape of a frustum of a circular cone. Such a combination of the photodetector chip and the carrier enables the omission of the positional adjustments of the photodetector chip on the carrier with respect to the X-axis and the Y-axis. A ferrule having a flange and a ferrule support member having a taper surface fitting the taper surface of the carrier are employed to omit the positional adjustment of the photodetector chip with respect to the Z-axis. Thus, the photodetector module can be assembled without requiring the positional adjustments of the photodetector chip relative to the optical fiber.

Photodetector module for coupling with optical fiber

Optical semiconductor device and production method thereof

A photo-semiconductor module is disclosed wherein a reliable airtight condition can be obtained and an operability in assembly can be improved. The photo-semiconductor module comprises a substrate carried in a casing, a photo-semiconductor chip mounted on the substrate, and a support member carried on the substrate and having an inclined face which is inclined by an angle of 45 degrees with respect to a surface of the substrate. A semi-spherical lens is securely mounted on the inclined face of the support member, and an opening formed in a side wall of the casing is sealed airtight by a glass member while an upper portion of the casing is sealed airtight by a lid. When an optical fiber is mounted onto the casing such that an end face thereof may be located in the opening in the side wall of the casing, the optical fiber and the photo-semiconductor chip are optically coupled to each other by way of the semi-spherical lens.

Photo-semiconductor module employing semi-spherical lens to enhance

A polishing machine for polishing the end faces of ferrules supporting coaxially aligned optical fibers to be connected in an optical fiber connector. The machine has a polishing disk composed of a rotating disk with a flat face, a rubber plate fixed on the rotating disk, and a thin metal elastic plate mounted on the rubber plate. The surface of the polishing disk is capable of being indented when the end face of a ferrule is pressed against the surface of the polishing disk. So, by passing the end face of the ferrule against the rotating polishing disk, and rotating the ferrule around its axis alternately to the left and right, the end face of the ferrule is polished approximately spherically. A revolving motion may be included for the ferrule. The curvature of the polished end face is determined by the force used to press the ferrule toward the polisher and the elasticity for the polishing disk. The surface of the polishing disk may be provided with a series of grooves arranged in a mesh pattern to catch and retain the abrasives, and when the ferrule approaches to the grooves, the abrasives gush out of the grooves to wet the end face to be polished. So, the polishing is done very smoothly. The chuck for clamping the ferrule is mountable and demountable from the polishing machine, while the ferrule is clamped therein. This makes the handling of the machine very easy, and prevents contamination and stain by abrasives.

Polishing machine for ferrule of optical fiber connector

An optical fiber connector structure for minimizing loss in an optical fiber connector. The connector includes cylindrical member for housing ferrule, a C-ring having a pawl positioned about the cylindrical member, and grooves formed in the cylindrical member for engaging the pawl so that the plug can engage the adapter so as to minimize loss in the connection with minimal amount of adjustment.

Positioning mechanism of optical fiber connector

Growing community of inventors

Kawasaki, Japan

Kaoru Moriya