The Furukawa Electric Co., Ltd.

Toshiaki Tsuda

Shigehito Yodo

Hiroshi Kobayashi

Takeshi Yagi

Shu Namiki

Yoshihiro Emori

Takeo Shimizu

Yuichiro Irie

Kazuhiko Nishiyama

Keiichi Aiso

Yu Mimura

Etsuji Katayama

Takeharu Yamaguchi

Toshihiko Ota

Toshihiko Ohta

Yasuhiro Ibusuki

Yasuo Uemura

Kazuyo Mizuno

Ikuo Ota

Hideo Aoyagi

Yukio Niino

This invention relates to an optical fiber for long period grating (LPG), LPG components, and manufacturing method of LPG used as a mode coupler, an optical filter, etc. The optical fiber for LPG comprises a core layer, a first cladding layer that surrounds said core layer and transmits the cladding modes, and a second cladding layer that surrounds said first cladding layer and confines the optical signal of the cladding mode within said first cladding layer. The LPG component comprises an optical fiber for LPG, a coating reinforcement to cover and reinforce said optical fiber for LPG. The manufacturing method of LPG comprises a step of preparation of an optical fiber, a step of constructing the LPG on a predetermined region in said core of said optical fiber by irradiating laser light on said region over a predetermined period corresponding to the LPG, on the predetermined part of said optical fiber, and a step which covers and reinforces said grating region.

Optical fiber for long period grating, long period grating component and manufacturing method of the same

Wavelength multiplex transmission is realized in which the temperature dependency of an EDFA is compensated for in relation to the wavelengths which are used. A first and a second long-period grating which have different periods from each other are formed in an optical fiber, ensuring that the peak wavelength of a waveform representing an optical transmission loss characteristic of the first long-period grating side is located on the shorter wavelength side than a transmission band and a peak wavelength of a waveform representing an optical transmission loss characteristic of the second long-period grating side is located on the longer wavelength side within the transmission band.

Optical component

An optical amplifier of the present invention comprises a pumping light source configured to output a pumping light, an amplifier unit configured to receive the pumping light from said pumping light source and amplify an optical signal that passes therethrough, and an optical fiber disposed between said pumping light source and said amplifier unit, said optical fiber including an optical filter that is configured to attenuate the optical signal from said amplifier unit.

Optical amplifier, light source module and optical system

A grating-type optical component having a high isolation ability at a light-blocking band and a small clad layer mode combination loss at a signal transmission band, and its manufacturing method are provided. A selected area on a core of an optical fiber is irradiated by ultraviolet beams emitted from an excimer laser source through a phase mask in order to produce high index of refraction areas and low index of refraction areas arranged alternately and periodically along the longitudinal axis of the optical fiber. This ultraviolet irradiation is terminated before the index of refraction, which is increasing due to the ultraviolet irradiation, reaches a target value. Then, the phase mask is removed, and the selected area of the core is again irradiated by ultraviolet beams, thereby completing the grating-type optical fiber.

Grating-type optical component and method of manufacturing the same

The invention relates to a dispersion slope compensating optical fiber which compensates the chromatic dispersion and dispersion slope of a positive dispersion slope optical fiber such as TRUE WAVE and increases reliability of wavelength division multiplex transmission in a wavelength from 1530 nm to 1610 nm. The center core (3) is covered by a side core layer (4), and the outside thereof is covered by a cladding layer (5), wherein the relationship between the relative refractive index differences .DELTA.1, .DELTA.2, .DELTA.3 of the center core (3), side core layer (4) and cladding layer (5) and pure SiO.sub.2 glass is established to be .DELTA.1) .DELTA.3) .DELTA.2, .DELTA.2/.DELTA.1=Rd.ltoreq.-0.45, and .DELTA.1.gtoreq.1.2%. The average dispersion slope in a wavelength from 1530 nm to 1610 nm is established to be -0.6 ps/nm.sup.2 /km or less, and the value obtained by dividing the dispersion value in the same wavelength by a dispersion slope is made 160 or less, wherein by connecting the dispersion shifted optical fiber to TRUE WAVE, whose average dispersion slope in said wavelength is approximately 0.07 to 0.1 ps/nm.sup.2 /km and whose dispersion value is greater by approximately 15 to 60 times than the dispersion slope, with a length which is shorter by approximately one-ninth than the length of TRUE WAVE, the dispersion in the said wavelength band can be drawn to nearly zero dispersion.

Dispersion slope compensating optical fiber

Growing community of inventors

Tokyo, Japan

Toshiaki Tsuda