Nippon Telegraph and Telephone Corporation

Other

Sumitomo Electric Industries, Limited

The Furukawa Electric Co., Ltd.

Fujikura Limited

Kazuo Hogari

Shin-ichi Furukawa

Hiroaki Sano

Hiroki Ishikawa

Shinji Nagasawa

Takehiro Hayashi

Ken Kanai

Shinichi Furukawa

Osamu Kawata

Yasumoto Kawamura

Shigeru Tanaka

Tomohiko Ueda

Yoshikyo Tamekuni

Tomoyuki Yokokawa

Yoshiyuki Suetsugu

Kazuhide Nakajima

Kazuhiro Takizawa

Yusuke Yamada

Naoki Okada

Masayoshi Yamanaka

Matsuhiro Miyamoto

Hideyuki Iwata

Yoshio Hashimoto

Kunihiro Toge

Yasuhiro Tamaki

Hiroshi Yokosuka

Shigeru Tomita

Izumi Sankawa

Tsuyoshi Imaizumi

Nobumasa Nirasawa

Toru Arikawa

Katsusuke Tajima

Yoshiyasu Satoh

Daisuke Iwakura

Masahiro Eguchi

Kiyotaka Nishioka

Koichiro Watanabe

Michio Suematsu

Jian Zhou

Kenji Morita

Shigekazu Hayami

Akihiro Otake

Fumiki Hosoi

Amono-coated optical fiber that has a bending loss characteristic in which an optical loss increase at a bending radius 13 mm is 0.2 dB/10 turn or less, an optical fiber ribbon that includes two-dimensionally disposed resin portions for bonding the adjacent 2-fiber mono-coated optical fibers in plural places, the resin portions being disposed apart from each other in the longitudinal direction of the optical fiber ribbon and an optical fiber cable that includes a cable core portion that stores twisting of plural units where the mono-coated optical fibers constituting the optical fiber ribbon are collected.

Optical fiber cable and optical fiber ribbon

A single mode fiber is provided which is suitable for high-speed, large-capacity optical communication and for optical wiring. The single mode fiber has a first cladding region with a uniform refractive index, a core region with a refractive index higher than that of the first cladding region, and a second cladding region including at least four air hole regions placed in the first cladding region. Optimization can be achieved by making the distance from the center of the core region to the air hole regions equal to 2&#x2013;4.5 times the core radius, and the air hole radius equal to or greater than 0.2 times the core radius. It is preferable the core radius be 3.7&#x2013;4.8 &#x3bc;m, the relative index difference of the core region from the first cladding region be 0.3&#x2013;0.55 %.

Hole-assisted single mode optical fiber

The present invention's optical cable is provided with optical fibers, a forming pipe for housing the optical fibers, a sheath provided around the forming pipe, and at least one pair of rip cords embedded in the sheath. The forming pipe is formed of a plurality of tapes so that it is dividable along its longitudinal direction. When dividing the optical cable, the rip cords are pulled to tear open the sheath, and the already split forming pipe is divided while staying adhered to the respective parts of the sheath. As a result, the division of the sheath and the forming pipe is carried out in one stroke, so that the optical fibers inside the forming pipe can be exposed easily and quickly.

Optical cable having forming tape and rip cords

A cable and a cable stripping method which facilities the stripping of an intermediate part of a cable having a cable core covered by a plastic sheath provided around the outer periphery without damaging the cable core. In a cable having a plastic sheath on a cable core either a groove is provided in the inner surface of the plastic sheath extending in the longitudinal direction of the cable. A ripcord is either fitted in the groove or adhered to the inner surface of the plastic sheath. In either case, the position-indicating means showing the position of the ripcord is provided on the outer surface of the plastic sheath at the point where the ripcord is fitted.

Cable, and method for removing sheath at intermediate part of cable

The invention is directed to an optical connector in which a length of an optical fiber,projects from a connection end surface (,) of a ferrule (,) is accurately set, a method of and a fixture for setting the projection length of the optical fiber. A recess surface (,) is formed in a ferrule receiving surface (,). A depth of the recess surface (,) is equal to a length an optical fiber (,) projects from the connection end surface (,) of the ferrule (,). The ferrule (,) is held by ferrule holding members (,) and (,), so that the ferrule (,) is abutted against the ferrule receiving surface (,) by the urging force of compression springs (,). Through the ferrule (,), an optical fiber cored line (,) is projected from the connection end surface (,) of the ferrule (,) and abutted against the recess surface (,). The optical fiber cored line (,) is held by a cored line holding member (,), the cored line holding member (,) is urged toward the ferrule receiving surface (,) by the urging force of compression springs (,), and a tip of the optical fiber (,) is brought into a pressure contact with the recess surface (,).

Optical connector and method of and fixture for setting projection length of optical fiber

The invention is directed to an optical connector in which a length of an optical fiber,projects from a connection end surface (,) of a ferrule (,) is accurately set, a method of and a fixture for setting the projection length of the optical fiber. A recess surface (,) is formed in a ferrule receiving surface (,). A depth of the recess surface (,) is equal to a length an optical fiber (,) projects from the connection end surface (,) of the ferrule (,). The ferrule (,) is held by ferrule holding members (,) and (,), so that the ferrule (,) is abutted against the ferrule receiving surface (,) by the urging force of compression springs (,). Through the ferrule (,), an optical fiber cored line (,) is projected from the connection end surface (,) of the ferrule (,) and abutted against the recess surface (,). The optical fiber cored line (,) is held by a cored line holding member (,), the cored line holding member (,) is urged toward the ferrule receiving surface (,) by the urging force of compression springs (,), and a tip of the optical fiber (,) is brought into a pressure contact with the recess surface (,). In this condition, an adhesive agent is injected into an adhesive injecting hole (,) of the ferrule (,) so that the optical fiber (,) is fixedly bonded to the ferrule (,), thereby obtaining an optical connector in which the optical fiber (,) projects a predetermined length from the connection end surface (,) of the ferrule (,).

Optical connector and method of and setting projection length of optical fiber

A short optical fiber,is incorporated in a ferrule,having a polished front end, so as to be projected from the rear end of the ferrule. In a base member,in which the short optical fiber is to be fitted into a hole,b, a V-groove,d to which the glass portion of an optical fiber is to be fixed, and a V-groove,e to which the coated portion is to be fixed are formed. A cover member,is placed on the base member. The base member,and the cover member,are clamped by clamp members,a and,b and the base member,presses to V-grooves. Wedges which are not shown are pressingly inserted between recessed,g and,c, and,h and,d, and an optical fiber,is inserted from the rear portion. Thereafter, the wedges are detached and the optical connector is attached to the terminal of the optical fiber

Optical connector and a method of attaching the same

An optical connector is provided where an biasing device,which biases a ferrule,having an optical fiber,secured thereinside and a tip end face,which has been polished, in a tip end face,direction, is located to the rear of a connection mechanism,for connecting the optical fiber,on the ferrule,side and a separately inserted optical fiber,at a rear end side of the ferrule,opposite to the front end face,The connection mechanism,has a construction which uses a mechanical splice, and is opened and closed by a release member inserted into an insertion opening,which is opened along an alignment axis direction. Hence the opening and closing operation does not interfere with the biasing device,so that operability is improved. Moreover, for this type optical connector there is provided an optical connector housing,which accommodates the ferrule. With this optical connector housing,by merely inserting the ferrule, the connection mechanism,for connecting the pair for optical fibers at the rear end side of the ferrule, and the stop ring,accommodating the connection mechanism,then assembly can be simply performed so that workability in assembling the optical connector is improved.

Optical connector and housing for optical connector

A spacer having a high-tensile member at the center thereof has grooves extending helically. Coated optical fibers have been disposed in each groove. This assembly is covered with a wound covering and further with a sheath. The proportion of the total sectional area of the coated optical fibers to the sectional area of each groove, i.e., the degree of packing, is regulated to 10 to 50%.

Spacer type optical fiber cable

The invention is directed to an optical connector in which a length of an optical fiber 5 projects from a connection end surface (16) of a ferrule (1) is accurately set, a method of and a fixture for setting the projection length of the optical fiber. A recess surface (33) is formed in a ferrule receiving surface (32). A depth of the recess surface (33) is equal to a length an optical fiber (5) projects from the connection end surface (16) of the ferrule (1). The ferrule (1) is held by ferrule holding members (35a) and (35b), so that the ferrule (1) is abutted against the ferrule receiving surface (32) by the urging force of compression springs (36). Through the ferrule (1), an optical fiber cored line (3) is projected from the connection end surface (16) of the ferrule (1) and abutted against the recess surface (33). The optical fiber cored line (3) is held by a cored line holding member (41), the cored line holding member (41) is urged toward the ferrule receiving surface (32) by the urging force of compression springs (42), and a tip of the optical fiber (5) is brought into a pressure contact with the recess surface (33). In this condition, an adhesive agent is injected into an adhesive injecting hole (43) of the ferrule (1) so that the optical fiber (5) is fixedly bonded to the ferrule (1), thereby obtaining an optical connector in which the optical fiber (5) projects a predetermined length from the connection end surface (16) of the ferrule (1).

Optical connector and method of and fixture for setting projection

A short optical fiber 2 is incorporated in a ferrule 1 having a polished front end, so as to be projected from the rear end of the ferrule. In a base member 3 in which the short optical fiber is to be fitted into a hole 3b, a V-groove 3d to which the glass portion of an optical fiber is to be fixed, and a V-groove 3e to which the coated portion is to be fixed are formed. A cover member 4 is placed on the base member. The base member 3 and the cover member 4 are clamped by clamp members 5a and 5b and the base member 3 presses the V-grooves. Wedges which are not shown are pressingly inserted between recesses 3g and 4c, and 3h and 4d, and an optical fiber 10 is inserted from the rear portion. Thereafter, the wedges are detached and the optical connector is attached to the terminal of the optical fiber 10.

An optical drop cable-units cable comprising a plastic pipe and a plurality of strandless optical drop cable-units and held in the plastics pipe, in which a space factor

Optical drop cable-units aggregate cable

An optical fiber path joint member according to the present invention includes a main path having an inlet and an outlet at respective ends thereof; and at least one joint path joining to the main path in one direction at an angle of equal to or less than 45.degree.. A method of blowing an optical fiber is comprised of the step of blowing an optical fiber into a pipe through the optical fiber path joint member according to the present invention.

Optical fiber path joint member and method of blowing optical fiber

A tube sheet is formed by integrating a plurality of tubes into the form of a sheet. The tube sheet is constricted in junction portions of the respective tubes so that the tube sheet is deformed in these junction portions. At least one such tube sheet is disposed around a center member to form a tube-aggregated cable.

Tub-aggregated optical cable

In an optical cable according to the present invention, a grooved spacer has a plurality of grooves in its circumference, and the cutting direction of the grooves is inverted at predetermined periods. Optical fibers are received in the respective grooves. On the circumference of the grooved spacer, a linear member is provided around the grooved spacer along the longitudinal direction of the optical cable at a predetermined period. The linear member is fixed to the grooved spacer by welding or bonding in the portions where they touch the outer circumferences of the grooved spacer so as to restrain the optical fibers. The linear member restraining the optical fiber to be taken out are cut in positions above the groove in which the optical fiber is received so that the required optical fiber can be taken out.

Optical cable and manufacturing method thereof

Growing community of inventors

Tokyo, Japan

Kazuo Hogari