Samsung Electronics Co., Ltd.

Hyundai Motor Company

Kia Motors Corporation

Myunghwa Ind. Co., Ltd.

Kyung-Hwan Oh

Un-chul Paek

Seung-Hun Oh

Ghie-Hugh Song

Ki-Un Namkoong

Hong-Seok Seo

Mun-Hyun Do

Un-Chul Paek

Man-Seok Seo

Young-Joo Chung

Jae-Kyun Doo

Hyun-Eu Jung

Young-geun Han

Xiao-Jun Li

The present disclosure provides an oil pump including a housing in which a space is formed, a rotor installed to be rotatable in an eccentric position in the housing and having vanes mounted along a circumference direction to be protruded and retracted in a radial direction of the housing, and an inner ring fitted to an inner surface of the housing and rotated along with the rotor when the rotor rotates. The housing is formed of a material harder than the material of the inner ring, and oil for lubrication is provided between the housing and the inner ring.

Oil pump of vehicle having inner ring

A dispersive optical fiber having variable core-cladding refractive index differences depending on wavelength is provided. The dispersive optical fiber includes a core made of silica doped with a first dispersive material, and a cladding made of silica doped with a second dispersive material, wherein the refractive indices of the first and the second dispersive materials cross each other at a predetermined cross wavelength. The first and second dispersive materials include boron and fluorine. The dispersive optical fiber is attained by doping each dispersive material into the core and the cladding, respectively, thereby minimizing transmission loss, and is capable of being coupled to general optical fibers.

Dispersive optical fiber using binary component silica

A multi-cladding optical fiber, a long-period optical fiber grating written in the optical fiber, and a writing method thereof are provided. The multi-cladding optical fiber includes a core made of germanium-doped silica (GeO,&mdash;SiO,), for guiding light, an inner cladding made of fluorine-doped silica (F&mdash;SiO,), the inner cladding having a refractive index smaller than that of the core and surrounding the core, and an outer cladding made of silica, the outer cladding having a refractive index smaller than that of the core and larger than that of the inner cladding and surrounding the inner cladding. Therefore, an optimized optical fiber can be designed. That is to say, an optical fiber having desired characteristics can be fabricated by adjusting at least one of the parameters including the amount of F doped into the inner cladding, the thickness of the inner cladding, the amount of GeO,doped into the core, the composition of SiO,in the outer cladding and the drawing tension of the optical fiber. Also, the refractive index of the core is periodically changed by periodically annealing the multi-cladding optical fiber, so that a stress-released long-period optical fiber grating can be obtained.

Multi-cladding optical fiber, long-period optical fiber grating written therein and writing method thereof

An optical fiber for wavelength division multiplexing (WDM) communications, includes: an inner core having a predetermined refractive index, formed to a first predetermined radius from a central axis of the optical fiber, an outer core having a refractive index which is lower than the refractive index of the inner core and gets linearly smaller from its inner side to its outer side, formed on an outer side of the inner core to have a second predetermined radius, and a cladding formed on an outer side of the outer core to have a third predetermined radius.

Optical fiber for wavelength division miltiplexing communications

An optical fiber for use in a fiber Bragg grating and a fiber Bragg grating using the same are provided. The optical fiber includes a core made of a material obtained by adding germanium oxide (GeO,) to silica (SiO,), for guiding light, and a cladding made by adding a material having a negative thermal expansion coefficient to silica (SiO,), the cladding having a refractive index lower than that of the core. Therefore, the change in Bragg wavelength depending on temperature can be minimized by forming the optical fiber using a material having a negative thermal expansion coefficient.

Optical fiber for use in Bragg grating and fiber Bragg grating using the same

There are provided an optical fiber rod overcladding apparatus and method, and an optical fiber drawing method. In the preform rod overcladding method, a preform rod is clamped in a top chuck and leveled, and a glass tube is mounted in a bottom chuck and leveled. The preform rod is coaxially inserted into a glass tube. Then, the glass tube is preheated by the furnace and heated by the burner until the glass tube reaches a softening point. The preform rod is completely sealed in the glass tube by sucking air in a clearance between the preform rod and the glass tube by application of a negative vacuum pressure. Thus, a preform is completed.

Apparatus and method for overcladding optical fiber preform rod and

Growing community of inventors

Seoul, South Korea

Kyung-Hwan Oh