Nippon Telegraph and Telephone Corporation

Ntt Corporation

Takui Uematsu

Hidenobu Hirota

Hiroyuki Iida

Naotsugu Ambe

Tetsuya Manabe

Yusuke Koshikiya

Tomohiro Kawano

Tatsuya Fujimoto

Sachi Tsujimura

Ryo Koyama

Takashi Ebine

Kazunori Katayama

An object of the present disclosure is to provide an optical coupling device capable of controlling a coupling rate of optical coupling between two coupling optical fibers. An optical coupling device of the present disclosure includes two coupling optical fibers each including a core and a clad and, between the two coupling optical fibers, a thickness variable member having a thickness between the two coupling optical fibers that varies by irradiation with light.

Optical coupling device and optical coupling system

The present disclosure is to provide a branch ratio measuring device, a branch ratio measuring method, and an optical multiplexer/demultiplexer circuit manufacturing method that do not require any optical sources for measurement. A branch ratio measuring device according to the present disclosure includes: an optical waveguide that has a cladding polished to the core or to the vicinity of the core; a first optical intensity measurement unit that is connected to one end of the core of the optical waveguide, and measures an optical intensity; and a second optical intensity measurement unit that is connected to the other end of the core of the optical waveguide, and measures an optical intensity.

Branch ratio measuring device, branch ratio measuring method, and optical multiplexing/demultiplexing circuit manufacturing method

An optical multiplexing and demultiplexing method of the present disclosure includes arranging, face to face, a polished surface of a coated optical fiber whose side surface is polished to a core or a vicinity of the core and a polished surface of an optical waveguide whose propagation constant varies in a longitudinal direction and whose side surface is polished to a core or a vicinity of the core, and aligning the polished surface of the coated optical fiber and the polished surface of the optical waveguide so that desired branching ratio is obtained from one end of the coated optical fiber to the end, distal to the former end, of the optical waveguide by relatively moving the polished surface of the coated optical fiber and the polished surface of the optical waveguide.

Optical multiplexing/demultiplexing method, optical multiplexing/demultiplexing circuit, and manufacturing method thereof

An object of the present invention is to provide an optical network system with high electric power efficiency, an operation method thereof, and an optical line terminal device capable of realizing the same. An optical network system () according to the present invention is a bus wiring type optical network system and includes an optical line terminal device () which transmits optical signals (Ls), an optical multiplexer/demultiplexer circuit () which inputs some of the optical signals (Ls) to an optical bus core wire (), and a photoelectric conversion unit () which converts the other of the optical signals (Ls) into electric power. The optical network system () can effectively utilize the electric power by reusing the electric power wasted in a port (Tf) of an optical fiber coupler.

Optical network system, operating method of optical network system, and optical line terminator

An object of the present invention is to enable identification of a reflection signal from a terminal portion of an optical fiber to be measured where a reflection signal caused by multiple reflection appears in an OTDR waveform in a mode in which an OTDR and the optical fiber to be measured are connected at a bent portion. The reflection signal caused by multiple reflection inevitably propagates through a distance equal to a distance between true reflection points more than the other reflection point, because of multiple reflection. Therefore, a distance between the reflection signal and another reflection signal is inevitably coincident with a distance between the other reflection signals. In contrast, in a case of a reflection signal from a terminal portion of the optical fiber, the distance between the reflection signal and another reflection signal is not coincident with the distance between the other reflection signals.

Termination determination device and termination determination method

An object of the present invention is to provide, in a local-light coupling technique for improving efficiency of work, an optical fiber local-light coupling apparatus configured to hardly affect communication between an OLT and an ONU while causing light to leak from a coated optical fiber in such an amount that makes it possible to confirm a communication state. The optical fiber local-light coupling apparatus according to the present invention includes a first jig including a concave portion curved in a longitudinal direction with respect to a coated optical fiber, and a probe configured to receive leakage light leaking from the coated optical fiber being bent; a second jig including a convex portion curved in the longitudinal direction with respect to the coated optical fiber, the convex portion being configured to sandwich the coated optical fiber between the convex portion and the concave portion of the first jig; a pressing unit configured to apply pressing force in a direction in which the concave portion of the first jig and the convex portion of the second jig approach each other to form a bend in the coated optical fiber; and a reflective film configured to cover a surface of the concave portion of the first jig except for a leakage light passage portion through which, among the leakage light, reception leakage light to be received by the probe passes, and reflect and return the leakage light other than the reception leakage light to the coated optical fiber.

Optical fiber lateral input/output device

An object is to provide a determination device that determines a state of a terminal end portion of a coated optical fiber at any location of the coated optical fiber. Reflection of test light varies in a reflection amount at each wavelength depending on a situation of the terminal end portion of the coated optical fiber. In other words, if the magnitude of the reflection amount at each wavelength can be known, the situation of the terminal end portion of the coated optical fiber can be estimated. The determination device according to the present invention is configured to make test light having a plurality of wavelengths incident from the optical fiber side and determine the test light based on a light intensity ratio of each reflected light beams reflected at the terminal end. In addition, reflection of test light varies in return loss at each wavelength depending on a situation of the terminal end portion of the coated optical fiber. If Rayleigh backscattered light can also be measured when measuring a reflection amount, the return loss can be known for each wavelength, and the situation of the terminal end portion of the coated optical fiber can be estimated from the result. The determination device according to the present invention is configured to make test light having a plurality of wavelengths incident from the optical fiber side and determine the test light based on a return loss at the terminal end.

Judgment device and judgment method

An object of the present invention is to provide a versatile optical fiber lateral output device that can deal with various types of optical fiber core wires. An optical fiber input-output device according to the present invention includes: a first jigincluding a recess portionand an optical input-output means; a second jigincluding a projection portionand a guide groove; and a pressing unitconfigured to apply a pressing force in a direction in which the recess portionof the first jigand the projection portionof the second jigapproach each other so as to bend an optical fiber core wire. Letting R1 be a curvature radius of the recess portionof the first jig, θ1 be a central angle of the recess portion, R2 be a curvature radius of the projection portionof the second jig, and θ2 be a central angle of the projection portion, R2≤R1 and θ2≤θ1 are satisfied.

An object is to provide a highly versatile local-light detection apparatus for an optical fiber capable of supporting various types of coated optical fibers. A local-light detection apparatus for an optical fiber according to the present invention includes a first jig including a recess curved in a longitudinal direction of a coated optical fiber and an optical input and output device configured to make light incident on the coated optical fiber in which a bend is formed and to receive light leaking from the coated optical fiber, a second jig including a protrusion curved in the longitudinal direction of the coated optical fiber, the protrusion being configured to sandwich the coated optical fiber between the recess of the first jig and the protrusion, a presser configured to apply a pressing force in a direction in which the recess of the first jig and the protrusion of the second jig approach each other and to form the bend in the coated optical fiber, and fiber guides disposed at both ends of the recess of the first jig in the longitudinal direction of the coated optical fiber, and to arrange the coated optical fiber on a predetermined path on the recess of the first jig regardless of a diameter of the coated optical fiber when the presser forms the bend in the coated optical fiber.

Optical fiber side input and output device

A manufacturing method of an optical splitter of the present disclosure includes: performing first processing that involves mounting a coated optical fiber on a jig configured to store the coated optical fiber, and polishing the coated optical fiber together with the jig until reaching a vicinity of a core of the coated optical fiber or the core of the coated optical fiber; performing second processing that involves applying a refractive index matching material having a refractive index lower than a refractive index of the core of the coated optical fiber onto a polished face of the coated optical fiber on the jig polished in the first processing or onto a polished face of an optical waveguide circuit having been polished in advance until reaching a vicinity of a core or reaching the core, and then bonding the polished faces to each other; and performing third processing that involves positionally aligning the polished faces bonded with each other in the second processing to move the jig or the optical waveguide circuit to a position at which a desired splitting ratio is obtained.

Manufacturing method and manufacturing apparatus of optical splitters

There are provided an optical fiber display system and an optical fiber changeover method each enabling an efficient optical fiber changeover work. The optical fiber display system according to the present invention includes a plurality of core wire identification terminals. Each of the core wire identification terminalsincludes: bent part formation unitsconfigured to form a bent part at an optional position of an optical fiberand to leak optical signals propagating through the optical fiberfrom the bent part; analysis unitsconfigured to acquire identification numbers of communication apparatuses (and) included in the leaked optical signals, the communication apparatuses (and) being connected to respective ends of the optical fiber; a communication unitconfigured to inquire of a databasestoring relationship between the optical fiber and the communication apparatuses about the acquired identification numbers of the communication apparatuses, and to receive an identification number of the optical fibercorresponding to the acquired identification numbers of the communication apparatuses, from the database; and a display unitconfigured to display the acquired identification numbers of the communication.

Optical fiber display system and optical fiber switching method

The present disclosure has an object to provide a technique for enabling a communication state to be confirmed not in a communication building but in a work site, and to provide a technique for enabling correct splicing between optical cables to be confirmed before fusion splicing. The present disclosure is a communication apparatus identification deviceincluding an optical fiber bent portionobtained by, when a portion of optical fibers to which communication apparatuses (the OLT-and the ONU) for which appropriateness of connection is to be determined are connected on opposite ends is bent, bending a portion of the optical fibers in a vicinity of a clearance provided between the optical fibers, the clearance having a range in which the communication apparatuses for which appropriateness of connection is to be determined can communicate with each other, and a MAC address analysis unitthat analyzes communication light leaked out of the bent portion of the optical fibers in the vicinity of the clearance to acquire identification numbers (MAC addresses) of the communication apparatuses for which appropriateness of connection is to be determined.

Communication apparatus identification device, optical fiber connection system, communication apparatus identification method, and optical fiber connection method

The present disclosure intends to provide an optical signal from an ONU according to a desired service usage state without using the ONU and an OLT. A simulated signal light generation apparatusaccording to the present disclosure is a simulated signal light generation apparatusfor simulating an uplink signal light generated in an optical network unit (ONU) in a passive optical network (PON), and the apparatus includes a usage state control unitthat sets a service usage state of the ONU, a signal generation unitthat generates an uplink signal frame according to the usage state set by the usage state control unit, and an electrical/optical conversion unitthat converts an electrical signal from the signal generation unitinto an optical signal, and the optical signal from the electrical/optical conversion unitis repeatedly transmitted to an optical fiber core

Simulation signal light generation device and simulation signal light generation method

An optical fiber side input and output device in which light can be input and output from the side of the tube core cable without adjusting a spacing even in a case where the thickness of the protective tube differs, and a method of designing the optical fiber side input and output device is provided. An optical fiber side input and output device has a structure in which an angle of a central angle of an apex portion of a first jig having a convex portion is appropriately set, and a loss insertion is kept equal to or less than a prescribed value by using a relationship between a spacing at the angle and an insertion loss when light is input and output from the side of the tube core cable.

Optical fiber side input/output device and design method

An object of the present disclosure is to provide a frequency division multiplexing coherent OTDR, a test method, a signal processing apparatus, and a program that can maintain, even in a case where a DFB laser is used, a spatial resolution equivalent to a spatial resolution achieved when a fiber laser or an external resonant laser is used. An OTDR according to the present disclosure includes a light incidence unit configured to change an optical frequency of light from a light source by a predetermined frequency interval at a predetermined time interval to generate test light pulses and cause the test light pulses to sequentially enter a fiber under test, a light reception unit configured to use the light from the light source as local light to coherently detect backscattered light from the fiber under test to acquire a received signal, and a computation unit configured to separate the received signal into signals with frequencies obtained by changing the optical frequency by the predetermined frequency interval, square amplitudes of the signals resulting from frequency separation to generate square values, perform Wiener filter processing on the square values, compensate values resulting from the Wiener filter processing for delay time when the test light pulses are caused to enter the fiber under test, and calculate an arithmetic mean of the compensated values.

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Musashino, Japan

Takui Uematsu