Seikoh Giken Co., Ltd.

Yuying Wu

Mitsuo Takahashi

Kunio Yamada

Minghua Wang

Guanming Lai

Dong Xia

Xiaoqing Jiang

Tomoyuki Mamiya

A thermo optical type variable optical attenuator suitable for application in an array type variable optical attenuator that realizes low crosstalk between neighboring waveguides in the array is provided. A thermo optical type variable optical attenuatorusing optical material having negative optical effect provides a multimode optical propagating partdisposed via a tapered partand a tapered partbetween single mode optical waveguidesand. A thin-film heateris disposed above the multimode optical propagating partat an angle of inclination &#x3b2; in relation to the direction of light propagation along a first optical waveguide. Moreover, a second optical waveguideoptically coupled with a side faceSof the multimode optical propagating partis provided at an angle of inclination&#x3b2; in relation to the direction of light propagation along the first optical waveguide

Thermoopic type variable optical attenuator and array type variable optical attentuator using this

A light-signal delaying device according to the present invention includes a linear guide rail and a pair of stages mounted on the linear guide rail. The device further includes a V-groove holder mounted on one of the stages, a pair of optical fiber collimators secured to the V-groove holder, a pair of reflecting mirrors mounted on the other stage such that reflecting surfaces thereof meet each other at 90&deg;, and an actuator engaging section for moving the stage along the linear guide rail.

Light-signal delaying device

An optical fiber wavelength filter which has superior optical properties and a manufacturing method for the same are disclosed. The optical fiber wavelength filter is composed of: a pair of glass ferrules which are transparent to ultraviolet rays and which are provided with optical fibers; and a thin dielectric multilayer film filter fixed between the distal ends of the ferrules. To manufacture the optical fiber wavelength filter, the optical fibers are bonded and secured to the pair of glass ferrules which are transparent to ultraviolet rays and the end surfaces thereof are ground. Then, the multilayer film filter and an adhesive agent which is hardened by the ultraviolet rays are disposed between the distal ends of the ferrules with the optical fibers, and the optical axes are aligned using a V-groove aligning jig. Upon completion of the optical axis alignment, ultraviolet rays are irradiated from outside to cure the adhesive agent to instantly fix the filter integrally to the distal ends of the pair of ferrules while the aligned ferrule are kept mounted on the V-grooved aligning jig.

Optical fiber wavelength filter and manufacturing method for the same

An optical fiber light source assembly is constructed by assembling a light emitting device, a condenser lens, and a ferrule receptacle means for receiving an optical fiber ferrule in a housing. The ferrule receptacle means is adjusted on its optical axis in relation to the housing and is then fixed to the housing. The ferrule receptacle is guided in the housing along a pair of engaged reference circumferences therebetween, and is moved back and forth through a screw connection while being turned. After a reference front end position of an inserted ferrule is made coincident with the image point of the light source, the ferrule receptacle means is fixed in the housing using fixing means. An adjusting instrument is used to adjust the position of the ferrule receptacle means in relation to the housing.

Optical fiber light source assembly and manufacturing method for the same

An optical device employing a GRIN rod lens, which optical device makes full use of the characteristics of a single-mode optical fiber and which permits extremely easy adjustment; an optical wavelength demultiplexer/multiplexer which utilizes a GRIN rod lens and a pass filter; and a bidirectional communications system which utilizes a pair of the aforesaid optical wavelength demultiplexers/multiplexers. The optical device is constructed by a GRIN rod lens, a reflecting surface which is disposed on one end surface of the GRIN rod lens, and a ferrule which supports the distal ends of a first optical fiber and a second optical fiber symmetrically with respect to a central axis thereof and which is connected to the other end surface of the GRIN rod lens with the central axis thereof aligned with the optical axis of the GRIN rod lens. The core diameter of the second optical fiber is made sufficiently larger than the core diameter of the first optical fiber. The first optical fiber is a single-mode optical fiber, while the second optical fiber is a multi-mode optical fiber.

Optical device and bidirectional communications system

An optical coupler is formed comprising a pair of optical fiber ferrules having four optical fibers fastened within a throughhole in the ferrule, a pair of contiguous graded index rod lenses, and a thin film between the graded index rod lenses which partially transmits incident light and reflects the remainder. One ferrule is attached to one graded index rod lens and another ferrule is attached to the other graded index rod lens. The central axes of the ferrules are aligned to the optical axes of the graded index rod lenses. The optical axis of each optical fiber in one ferrule is aligned to the optical axis of a corresponding optical fiber in the other ferrule by rotating the former ferrule around its optical axis so that the four optical fibers of the ferrule are symmetrically arranged with respect to the optical axis of the graded index rod lens to which the ferrule is attached. The ferrules, graded index rods lenses and thin film are fastened together.

Optical coupler constructed using optical fiber ferrules

An optical fiber LED assembly for coupling light from a light source element to an optical fiber via a rod lens with distributed refractive index provides improved stability by controlling deterioration in the optical coupling efficiency of the assembly with a lapse of time. The light source element includes a light emitting element which radiates light through a transparent aperture-covering plate of a can in which it is located. The light source element is supported by a first cylindrical holder. A second cylindrical holder supports a rod lens with distributed refractive index at one end thereof and accepts and supports the distal end of an optical fiber ferrule. The second cylindrical holder is inserted and fixed in the first cylindrical holder, the rod lens with distributed refractive index being directed toward the transparent aperture-covering plate of the light source element. A seal ring is inserted in the first holder between the light emitting element and the second holder and a refractive index matching agent is hermetically charged in the space formed by the transparent aperture-covering plate and the second holder.

Growing community of inventors

Matsudo, Japan

Yuying Wu