Hitachi Cable, Inc.

Hitachi, Ltd.

Yuuetsu Takuma

Hiroshi Kajioka

Kohdo Yamada

Masahiko Ibamoto

Shuji Eguchi

Seikichi Tanno

Hideki Asano

Junji Mukai

Noriaki Taketani

Tatsuya Kumagai

Tatsuo Teraoka

Yukio Shimazaki

Toshihide Tokunaga

Kazuya Murakami

Masashi Nakamura

Koudo Yamada

A method of producing an elliptic core type polarization-maintaining optical fiber comprises the steps of providing a glass rod comprising a cladding glass layer around the periphery of a core glass layer, the cladding glass layer having a softening point higher than the softening point of the core glass layer, removing two side surface portions of the glass rod by machining along the axial direction of the glass rod to form a machined rod noncircular in cross section, outside depositing fine silica glass particles on the periphery of the machined rod, followed by sintering to provide a support glass layer having a softening point higher than the softening point of the cladding glass layer, and drawing the thus obtained glass rod body as an optical fiber preform. Since the portion for constituting the core of the optical fiber is formed by machining, the core is permitted to have a high ellipticity. An optical fiber with the desired size and birefringence index is obtained by regulating the conditions of production.

Method of producing elliptic core type polarization-maintaining optical

An optical part for light transmission comprises a light conductor formed of a core of a transparent material and a clad of a material having a smaller refractive index than that of the core material, and a light emitting and/or receiving element, wherein the light emitting and/or receiving element is integrally combined with the core of the light conductor by a same material as the core material or by a material having a same refractive index as that of the core material and having a greater rigidity than that of the material forming the clad and/or jacket. The optical part can be used in a high temperature environment as well as a room temperature environment without involving any appreciable loss in light transmission.

Optical part including integral combination of optical fiber and light

Two opposite portions of the surface of a core rod whose section is circular are removed by machining in the longitudinal direction thereof, so that the section of the core rod is transformed into a non-circular shape. On the surface of the thusly shaped non-circular core rod, glass particulates are accumulated, and then the glass particulates accumulated on the core rod are sintered to create a preform. Then, the preform is heated and drawn, so that a polarization-maintaining optical fiber of non-circular section is obtained.

Method of manufacturing polarization-maintaining optical fibers

A polarized wave preserving fiber has a core at its center, cladding, an oval jacket, and a support member in order to improve transmitting property of the polarized single mode by adjusting the refractive index distribution and the ellipticity of the oval jacket.

Polarized wave preserving fiber

Growing community of inventors

Hitachi, Japan

Yuuetsu Takuma