Sumitomo Electric Industries, Limited

Kyocera Document Solutions Inc.

Yoshiaki Tamura

Tetsuya Haruna

Masaaki Hirano

Hirotaka Sakuma

Yuki Kawaguchi

Keisei Morita

Yoshinori Yamamoto

Masato Suzuki

Takemi Hasegawa

Tetsuya Hayashi

Tetsuya Nakanishi

Atsushi Inoue

Shigehiro Nagano

Yoshihiro Saito

Suguru Takasaki

Saori Kubara

Akiko Funakoshi

Nobuhiro Hikichi

Yoshihiro Tukuda

An optical fiber is formed from silica-based glass. The optical fiber includes a core including a central axis and a cladding surrounding the core. A refractive index of the core is greater than a refractive index of the cladding. The core contains chlorine, and one or more kinds of elements selected from an element group consisting of alkali metal elements and alkaline earth metal elements. A relative refractive index difference of the core based on a refractive index of pure silica is 0.00% or greater and 0.15% or less. An average concentration of fluorine in the cladding is 1.2% or less in a mass fraction.

Optical fiber

An optical fiber includes a core, and a cladding. When a refractive index of silica glass is set as n, a refractive index of the core is set as n, and a refractive index of the cladding is set as n, a relative refractive index difference Δ defined by Expression (1):Δ[%]=100×()/2  (1)is 0.2% or higher. A ratio of a maximum value of a concentration of the dopant composed of the alkali metal element or the alkaline-earth metal element in the cladding to a maximum value of a concentration of the dopant composed of the alkali metal element or the alkaline-earth metal element in the core is 0.06 or higher and 0.25 or lower.

One embodiment of the present disclosure relates to an optical fiber having lower transmission loss. The optical fiber is an optical fiber comprised of silica-based glass and includes a core including a central axis and a cladding. The cladding surrounds the core and has a refractive index lower than a refractive index of the core. The core contains phosphorus, chlorine, and fluorine. The core further includes an alkali metal element or an alkaline earth metal element. In a cross section of the optical fiber orthogonal to the central axis, a ratio Rp/Ra of a radius Rp of a phosphorus-containing region with respect to a radius Ra of the core is 0.3 or more.

An optical fiber has a structure uniform in a longitudinal direction. This optical fiber includes a core and a cladding that surrounds the core in a cross-section perpendicular to the longitudinal direction. A refractive index of the cladding is lower than a refractive index of the core. The cladding has, in the cross-section, an inner cladding layer including an inner circumferential surface of the cladding, and an outer cladding layer including an outer circumferential surface of the cladding. The inner cladding layer contains fluorine. The inner and outer cladding layers have refractive indexes different from each other. The outer cladding layer includes a local maximum portion where a residual stress, which is a tensile stress, becomes local maximum. A radial distance between the local maximum portion and an inner circumferential surface of the outer cladding layer is 10 &#x3bc;m or less.

An image forming apparatus includes a printing section, an electrostatic touch panel, a power source circuit section, and a contact member. The printing section performs printing. The electrostatic touch panel receives a touch operation by a user. The power source circuit section receives supply of power from a commercial power source and supplies power to the printing section and the electrostatic touch panel. The contact member is connected to a ground of an image forming apparatus and is touched by a user operating the electrostatic touch panel.

Image forming apparatus including a contact member for operating an electrostatic touch panel

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

The present invention relates to a method of manufacturing an optical fiber preform for obtaining an optical fiber with low transmission loss. A core preform included in the optical fiber preform comprises three or more core portions, which are each produced by a rod-in-collapse method, and in which both their alkali metal element concentration and chlorine concentration are independently controlled. In two or more manufacturing steps of the manufacturing steps for each of the three or more core portions, an alkali metal element is added. As a result, the mean alkali metal element concentration in the whole core preform is controlled to 7 atomic ppm or more and 70 atomic ppm or less.

Method of manufacturing optical fiber preform and optical fiber preform

The present embodiment relates to an optical amplifier and the like having a structure for enabling efficient use of pumping light while avoiding complication of a device structure. In such an optical amplifier, since pumping light from a pumping light source is supplied to each core of an amplification MCF, a coupling MCF in which adjacent cores form a coupled core is arranged between the amplification MCF and the pumping light source. The pumping light source is optically connected to a specific core of the coupling MCF, and pumping light is coupled from the specific core to remaining cores except the specific core in the coupling MCF before pumping light is supplied to each core of the amplification MCF. This enables coupling of pumping light between optically connected cores between the amplification MCF and the coupling MCF.

Optical amplifier and multi-core optical fiber

An optical fiber having an effective area that can be easily increased and bending loss characteristics that can be easily improved is provided. The optical fiber includes a glass fiber including a core and a cladding; a first resin coating layer that is in contact with the glass fiber and surrounds the glass fiber; and a second resin coating layer that surrounds the first resin coating layer and has a Young's modulus greater than a Young's modulus of the first resin coating layer. An effective area is greater than or equal to 110 &#x3bc;mand less than or equal to 180 &#x3bc;mat a wavelength of 1550 nm. A cable cut-off wavelength is less than or equal to 1530 nm. A uniformity of thickness of the first resin coating layer is greater than or equal to 60% and less than or equal to 80%.

Optical fiber, colored optical fiber, and optical transmission system

An optical fiber is formed from silica glass, and includes a core, a first cladding which surrounds the core and has a refractive index lower than the refractive index of the core, and a second cladding which surrounds the first cladding and has a refractive index that is lower than the refractive index of the core and higher than the refractive index of the first cladding. The second cladding is divided into an inner region that is in contact with the first cladding and an outer region which surrounds the inner region and has a thickness that is half the thickness of the second cladding or less, while being 5 &#x3bc;m or more. The residual stress in at least a part of the outer region is a compressive stress.

An image forming apparatus includes a power switch, a power supply circuit, a power supply control unit, and a main control unit that sends a control signal to the power supply control unit and allows the power supply control unit to perform the power supply process based on the control signal. The power supply control unit starts to count pressing time as an elapsed time while the power switch is kept pressed. If the pressing time reaches a predetermined time without a change in the control signal, the power supply control unit forcibly starts a power shutdown process. If the control signal changes before the pressing time reaches the predetermined time, the power supply control unit starts the power shutdown process after receiving from the main control unit the control signal requesting for the power shutdown process.

Image forming apparatus

The optical fiber offered is capable of not only restraining the attenuation due to glass defects, but also reducing the increase of manufacturing cost. The optical fiber is made of silica glass and includes a core and a cladding. The cladding encloses the core and has a refractive index smaller than that of the core. When the core is divided into inner core and outer core at half of the radius of the core, the average chlorine concentration of the inner core is larger than that of the outer core. The core includes any of the alkali metal group.

The optical fiber has an effective area that is greater than or equal to 110 &#x3bc;mand less than or equal to 180 &#x3bc;mat a wavelength of 1550 nm and a cable cut-off wavelength of less than or equal to 1530 nm. An average value of a glass outer diameter in a longitudinal direction is 125&#xb1;0.5 &#x3bc;m. When &#x3c3; is a standard deviation of the glass outer diameter in the longitudinal direction, 3&#x3c3; is greater than or equal to 0.1 &#x3bc;m and less than or equal to 0.5 &#x3bc;m.

Optical fiber, coated optical fiber, and optical transmission system

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 preform includes a silica-glass core portion, and a cladding portion surrounding the core portion, the cladding portion being composed of a fluorine-containing silica glass having a lower refractive index than the core portion, the core portion including a first region that does not include the central axis thereof, the first region containing a first dopant selected from sodium, potassium, and compounds thereof, and a second region that includes the central axis, the second region containing a second dopant that reduces the viscosity of the silica glass, the second dopant having a diffusion coefficient of 1&#xd7;10cm/s or more and less than the first dopant at 2,000&#xb0; C. to 2,300&#xb0; C., in which the entire core portion has an average first dopant concentration of 10 atomic ppm or more and 2,000 atomic ppm or less and an average second dopant concentration of 10 atomic ppm or more.

Growing community of inventors

Yokohama, Japan

Yoshiaki Tamura