Sumitomo Electric Industries, Limited

Sony Corporation

Nissan Motor Company Limited

Kao Corporation

Mitsubishi Electric Corporation

Yoshinori Yamamoto

Eisuke Sasaoka

Masaaki Hirano

Yuki Kawaguchi

Masao Ohyama

Takashi Fujii

Takemi Hasegawa

Kenichiro Murakami

Yasuo Osada

Hiroshi Meguro

Yutaka Sato

Yasuhiro Yoshida

Yoshiaki Tamura

Takatoshi Kato

Masato Suzuki

Toshiaki Yoshikawa

Itaru Sakabe

Tomoyuki Yokokawa

Yutaka Fukuyama

Keisei Morita

Tetsuya Haruna

Shusaku Katakura

Osamu Takahashi

Noriaki Iwaguchi

Teruhiko Kumada

Takeshi Fujii

Takashi Takada

Tadao Fujita

Kumiko Tachibana

Yoshikazu Ishimatsu

Hidetomo Nakagawa

Reiji Morioka

Kenji Kawakami

Kenichi Horikawa

Daigo Kishi

Masakazu Takami

Hisanori Watanabe

Tatsuya Mototake

Shigeru Mizusawa

Mitsugu Iwatsubo

Kohei Kamiya

Yoshinori Tanikawa

Kenji Ohhara

Masao Ri

Mitsuru Hanajima

Takamitsu Hase

Yasushi Matsumoto

Tsukasa Takagi

Toshimasa Takahashi

Suguru Takasaki

Tsuyoshi Nagasawa

Hisashi Tanji

Saori Kubara

Keizo Ishida

Tatsuyuki Outou

Shuusaku Katakura

Norikazu Horikawa

Akihito Moriya

Kazunari Fujimoto

Kazunori Nobumoto

Yuji Sudoh

Hideo Imai

Yoshinobu Hayashi

Akira Takada

An optical fiber line of one embodiment comprises an HNLF, an SMF, and an MFD transition portion. The MFD transition portion includes end portions of both the HNLF and the SMF facing with a fusion point thereof, and is a section in which an MFD changes such that a difference between a maximum value and a minimum value is 0.3 &#x3bc;m or more for a 100 &#x3bc;m-length. A splicing loss of the HNLF and the SMF at 1,550 nm is one-fifth or less than an ideal butting loss at stationary portions thereof. A total length of the MFD transition portion is 10 mm or less. In a region between one end surface of the HNLF at the fusion point and the other end surface separated from the one end surface by 50 &#x3bc;m or more and 300 &#x3bc;m or less, the MFD increases monotonically from the other end surface to the one end surface.

Optical fiber line, module, and method for manufacturing optical fiber line

An optical fiber according to an embodiment includes a core and a cladding. The average value n1_ave of the refractive index of the core, the minimum value nc_min of the refractive index of the cladding, and the refractive index n0 of pure silica glass satisfy relationships of n1_ave&#x3e;nc_min and nc_min&#x3c;n0. The cladding contains fluorine. The fluorine concentration in the cladding is adjusted to be minimum in the outermost portion of the cladding including the outer peripheral surface of the cladding.

Optical fiber

An optical fiber according to an embodiment includes: a core; an inner cladding surrounding the core and having a refractive index smaller than a refractive index of the core; an outer cladding surrounding the inner cladding and having a smaller refractive index than the refractive index of the core and having a refractive index greater than the refractive index of the inner cladding, in which a ratio of a caustic radius to a MAC-value (caustic radius/MAC-value) at a bending radius of 10 mm at a wavelength of 1625 nm is 2.70 &#x3bc;m or more.

The present embodiment relates to an optical fiber line or the like configured by connecting a single-mode optical fiber with a cladding containing fluorine and a large Aoptical fiber by TEC connection, and a connection state between such two types of optical fibers is set such that a connection loss expressed in dB of a fundamental mode is equal to or less than 55% of an ideal butt loss expressed in dB at a wavelength of 1550 nm.

Optical fiber line and optical fiber line manufacturing method

An optical fiber made of silica glass includes a core having a maximum refractive index n, a depressed portion surrounding the core and having an average refractive index n, and cladding surrounding the depressed portion and having an average refractive index n. In the optical fiber, n&#x3e;n&#x3e;n. The optical fiber has a local maximum value of chromatic dispersion within a wavelength range of 1530 nm to 1610 nm, and the local maximum value is &#x2212;2 ps/nm/km or greater and below 0 ps/nm/km.

Optical fiber and light source device

An actual slip amount (S) of a torque converter is calculated by subtracting an actual input shaft rotational speed (Nr) of an automatic transmission from an engine rotational speed (Ne), which is the rotational speed of a crankshaft. Then, an engine rotational speed for display (Nd) is calculated by adding a slip amount adjusted for display (Sp), which is obtained by applying a predetermined correction process to the actual slip amount (S) to the actual input shaft rotational speed (Nr). The above described correction process may be a first-order-lag filter processing, for example. Thus, even when the actual slip amount (S) temporarily increases or decreases, a temporary increase or decrease in the engine rotational speed for display (Nd) may be suppressed. In other words, fluctuation or variation in the engine rotational speed for display (Nd) is suppressed. Further, Further, it is possible to provide the driver with a visually excellent direct-feeling display of engine speed Nd without impairing the drivability.

Rotational speed display device

Provided are an optical fiber that has a short zero-dispersion wavelength, has high nonlinearity, and can cause broadband supercontinuum light to be generated with high efficiency, and a light source device that can output broadband supercontinuum light by using the optical fiber. A light source device includes a seed light source that outputs light with a central wavelength 1000 nm or more and 1650 nm or less and an optical fiber that receives the light output from the seed light source, allows the light to propagate therethrough, causes broadband light with an expanded band to be generated in accordance with a nonlinear optical phenomenon while the light propagates therethrough, and outputs the broadband light. The optical fiber is composed of silica glass, has a zero-dispersion wavelength of 1290 nm to 1350 nm, and has an effective area of 14 &#x3bc;mor smaller at a wavelength of 1550 nm.

An optical fiber includes a core having a maximum refractive index n, and cladding provided around the core and having a refractive index nthat is lower than the maximum refractive index n. A radial refractive-index profile of the core is expressed with an exponent &#x3b1; that is 1.5 to 10. A relative refractive-index difference &#x394;at a center of the core that is expressed as &#x394;=100&#xd7;(n&#x2212;n)/(2n) is 0.3% to 0.5%. A diameterof the core is 9 &#x3bc;m to 14 &#x3bc;m. A zero-dispersion wavelength is 1300 nm to 1324 nm. A cable cutoff wavelength &#x3bb;cc is 1260 nm or shorter. A bending loss at a wavelength of 1550 nm in a case where the optical fiber is wound by ten turns with a bend diameter of 30 mm is 0.25 dB or smaller.

An actual gear ratio change amount (&#x394;Gr) is calculated by subtracting a pre-shift gear ratio (Gb) from an actual gear ratio (Gr). A gear ratio (G) is calculated by multiplying the actual gear ratio change amount (&#x394;Gr) by a predetermined coefficient (C) and adding the product value to the pre-shift gear ratio (Gb). When the shift is an upshift, the gear ratio (G) is compared with aa target gear shift ratio (Ga), and the greater value is set as a virtual gear ratio (Gv). When the shift is a downshift, then the gear ratio (G) is compared with the target gear ratio (Ga) and the smaller value is set as the virtual gear ratio (Gv). A virtual input shaft rotational speed (Nv) is calculated by first dividing the actual gear ratio (Gr) by the virtual gear ratio (Gv) to obtain a quotient and by dividing the actual input shift rotational speed (Nr) by that quotient. A slip amount (S) is calculated by subtracting the actual input shaft rotational speed (Nr) of the automatic transmission () from the engine rotational speed (Ne). Finally, the engine rotational speed for display (Nd) is calculated by adding the slip amount (S) to the virtual input shaft rotational speed (Nv).

Rotational engine speed display device

Provided is an optical fiber having W-shaped refractive-index distribution and in which a micro-bend loss in an actual usage waveband is reduced. The optical fiber includes a core, inner cladding that surrounds the core and has a refractive index smaller than a refractive index of the core, and outer cladding that surrounds the inner cladding and has a refractive index smaller than the refractive index of the core and larger than the refractive index of the inner cladding. When a coupling coefficient between a fundamental mode and a cladding mode is denoted by C, a coupling coefficient between the fundamental mode and a higher-order mode is denoted by C, and a coupling coefficient between the higher-order mode and the cladding mode is denoted by C, Cdefined as C=C+CChas a minimum value at a wavelength ranging between 1520 nm and 1630 nm.

A low attenuation optical fiber having a core doped with Ge is offered. The optical fiber consists of a glass part and a covering part formed around the glass part. The glass part is made of silica glass and includes: a Ge-doped center core region; an optical cladding layer formed around the center core region; and an optical cladding layer formed around the cladding layer. The relationship of &#x394;1&#x3e;&#x394;3&#x2265;&#x394;2 holds, where &#x394;1, &#x394;2, and &#x394;3 are the relative refractive index differences of the center core region, the cladding layer, and the cladding layer, respectively with respect to pure silica glass. The average outer diameter of the glass part is in the range of 125&#xb1;0.5 &#x3bc;m in the longitudinal direction, and 3&#x3c3; is in the range of 0.1 &#x3bc;m to 0.5 &#x3bc;m, where &#x3c3; is the standard deviation of the outer diameter in the longitudinal direction.

Optical fiber and colored optical fiber

The present embodiment relates to an optical fiber having a W-type refractive index d profile or a trench-type refractive index profile and having reduced microbending loss in a wavelength band to be actually used. The optical fiber includes a center core, an inner cladding surrounding the center core, and an outer cladding surrounding the inner cladding. The inner cladding has a refractive index lower than a refractive index of at least the center core and the outer cladding has a refractive index lower than the refractive index of the center core and higher than the refractive index of the inner cladding. Wavelength dependency of microbending loss has a local maximal value and a shortest wavelength &#x3bb;where the microbending loss becomes 10% of the local maximal value is longer than 1560 nm.

Optical fiber and optical fiber transmission path

The present invention relates to an optical fiber which can improve OSNR in an optical transmission system in which Raman amplification and an EDFA are combined. With respect to the optical fiber, a predetermined conditional formula is satisfied by an effective area Aeff[&#x3bc;m] at a wavelength of 1450 nm, a transmission loss &#x3b1;[/km] at a wavelength of 1450 nm, and a transmission loss &#x3b1;[dB/km] at a wavelength of 1550 nm. Further, with respect to the optical fiber, another predetermined conditional formula is satisfied by an effective area Aeff[&#x3bc;m] at a wavelength of 1550 nm, and a transmission loss &#x3b1;[/km] at a wavelength of 1550 nm.

Optical fiber and optical transport system

An optical fiber cable has a sectional area of Ac [&#x3bc;m] and housing a number N of optical fibers. A transmission loss &#x3b1;[dB/km], a mode field diameter W [&#x3bc;m], an effective area Aeff [&#x3bc;m], an effective length L[km], and a wavelength dispersion D [ps/nm/km] of each of the optical fibers at a wavelength of 1550 nm satisfy a predetermined equation.

Optical fiber cable

An optical fiber cable has a sectional area of Ac [mm] and housing a number N of optical fibers. A transmission loss &#x3b1;[dB/km], a mode field diameter W [&#x3bc;m], an effective area Aeff [&#x3bc;m], an effective length L[km], and a wavelength dispersion D [ps/nm/km] of each of the optical fibers at a wavelength of 1550 nm satisfy a predetermined equation and the transmission loss of the optical fiber at the wavelength of 1550 nm is 0.19 dB/km or less, and the effective area of the optical fiber is in a range from 125 to 155 &#x3bc;m.

Growing community of inventors

Yokohama, Japan

Yoshinori Yamamoto