Other

Showa Electric Wire & Cable Co., Ltd.

Nippon Telegraph and Telephone Corporation

Swcc Showa Cable Systems Co., Ltd.

Kenichi Muta

Masaru Kobayashi

Yuichi Murakami

Keiko Shiraishi

Yuichi Morishita

Tomotaka Murase

Mituo Itoh

Takashi Yoshida

Ryo Nagase

Takushi Yoshida

Koichi Arishima

Seiko Mitachi

Shin Sumida

Yoshiaki Takeuchi

Eiji Matsuyama

Masaru Watanabe

Jen-Hung Chu

Hen-Tai Shang

Masashi Saijo

Kazunari Sugi

Makoto Sumita

Yumi Ariga

Akira Kumagai

Kohichi Arishima

Akiyoshi Naruse

Toyomitsu Yamamoto

Provided is a device for removing coating on an optical fiber. The device has a cutting depth limiting surface disposed on a receiver body and a cutting blade attached between a pusher body and a fixing block. The cutting blade is made from plastics and has a specified bending elasticity. An optical fiber is inserted between the cutting blade and the limiting surface. During operation, the cutting blade cuts into a covering on the optical fiber. A high precision in arranging the cutting blade is not required.

Device for removing coating on optical fiber

An optical attenuator which provides almost the same degree of attenuation even when the difference in wavelength of two different kinds of input optical signals is small. Another optical attenuator is provided with a dopant concentration in a technically realizable range which increases the difference in optical attenuation of two different kinds of input optical signals. Almost the same degree of attenuation may be obtained even when the difference between wavelengths is small by canceling the wavelength dependency of attenuation of the dopant by raising the refractive index of an axially central portion of the core as compared to that of the peripheral portion of the core and by taking into account the type and area of the dopant and the ratio of the difference &Dgr; between the refractive indexes of the cladding and the axial portion of the core and the difference &Dgr; between the refractive index of the cladding and the refractive index of the peripheral portion, i.e., &Dgr; . On the other hand, the difference of attenuation is increased while suppressing the concentration of dopant to the realizable range.

Optical fiber attenuator with attenuating dopant limited to a central or peripheral area of the fiber core

Abnormal losses outside a reflection band attributable to a mismatch of core field diameters are suppressed. A photo-sensitive fiber comprising a core,and a cladding having a cladding inner layer and a cladding outer layer formed in this order around the core, in which at least the core is photo-sensitive to form a grating. The core and cladding inner layer include a photo-sensitive dopant for increasing the refractive index. The core additionally includes a first non-photo-sensitive dopant for increasing the refractive index and the cladding inner layer additionally includes a second non-photo-sensitive dopant for creasing the refractive index.

Photo-sensitive fiber

Disclosed are optical fibers for optical attenuation comprising a core and a cladding, wherein the cladding comprises two or more parts different from each other in their refractive indices and/or the attenuating dopant existence. By using the optical fibers for optical attenuation of the present invention, an optical attenuator which can effectively reduce the effect of cladding mode upon coupling of optical fibers and is excellent in characteristic stability can be manufactured at a low cost.

Optical fibers for optical attenuation

Growing community of inventors

Kawasaki, Japan

Kenichi Muta