JP2009128853A - Optical coupler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical coupler that is convenient, small and inexpensive. <P>SOLUTION: The optical coupler 60 that is arranged on a tray (not shown) mounted in a closure 50 has a video coupler part 70-1 and a data coupler part 70-2 built in, so that the number of optical couplers in use can be made one. The video optical fiber strand 62-1 to 62-4 and the data optical fiber strand 62-a to 62-d drawn from the optical coupler 60 are paired by two each, made into two-core ribbons and coupled to each other, so that the selection of the two pieces is facilitated in a connecting operation, with workability greatly improved. For example, in the case where a certain user's home has a data circuit already installed and where a video circuit is to be added at a later date, there is no need of newly installing an additional video optical coupler in the closure 50. As a result, no connecting arrangement of optical fibers strand (or optical fiber cores) incidental to the additional optical coupler installation is necessary, which results in superior workability. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is an example of an access network configuration in FTTH (Fiber To The Home), which is an access optical communication network (network) configuration method in which an optical fiber is used as a transmission line and is directly drawn from a station facility to each user's house. PON (Passive Optical Network, one optical cable from a relay station that is branched by an optical passive element called an optical splitter (optical coupler) and connected to the user's home), etc. It is related with the optical coupler to match.

  Conventionally, as a technique related to the FTTH-PON system and the optical coupler, there are those described in the following documents, for example.

JP 2003-185865 A JP 2005-294994 A

  Patent Document 1 describes an optical coupler technique, and Patent Document 2 describes an FTTH-PON system technique.

  As described in Patent Document 2 and the like, in recent years, FTTH, which is a broadband service for general homes using optical fibers (for example, data communication, video distribution, Internet Protocol telephone called IP telephone) has been widely used. Have been doing. For example, when a consumer customer who is a user receives a data communication and video distribution service by FTTH, the service provider lays an optical fiber from the station equipment to the user's house. There are the following two methods.

(1) Two-core communication system This is a two-core laying method in which two optical fibers, a data communication optical fiber and a video distribution optical fiber, are laid.

(2) Single-core communication system This is a single-core laying method for laying one optical fiber for data communication and video distribution. In this method, two signals of data and video are multiplexed / demultiplexed using a wavelength division multiplexing (WDM) device for wavelength multiplexing / demultiplexing.

  The single-core communication system can reduce the number of optical cable cores and the amount of equipment compared to the two-core communication system, but it is necessary to use a wavelength multiplexing / demultiplexing WDM device for both the station equipment and the user's house. On the other hand, the two-core communication system has excellent design flexibility when the number of video and data (Internet) subscribers in the same area is extremely different, or when it is desired to separate physical lines for each service. ing.

  FIG. 6 is a schematic configuration diagram of a conventional FTTH-PON system of the two-core communication system described in Patent Document 2 and the like.

  This FTTH-PON system of the two-core communication system includes a station facility 10 that transmits and receives video signals and data signals, and a main line / supporting optical cable 20 installed by a support 13 is connected to the station facility 10. ing.

  Here, the trunk line / supporting optical cable 20 is, for example, an optical cable having a supporting line with high aerial laying strength. In general, an optical fiber has a triple structure of a core called a core, a portion called an outer clad, and a covering portion covering them. By making the refractive index of the core higher than that of the clad, Light is propagated to the core in the center by reflection and refraction. Both the core and the clad are made of quartz glass or plastic having a high light transmittance. The state of only the core and the clad without the coating part is simply called “optical fiber”, the surface of the optical fiber coated with silicon resin or the like is “optical fiber strand”, and the optical fiber strand is coated with nylon fiber or the like The optical fiber core wire is called an “optical fiber core wire”, and the optical fiber core wire is covered with a high tensile strength fiber or the like and an outer skin. A plurality of optical fiber core wires coated with a sheath called a protective sheath may be called an “optical fiber cable” (or “optical cable”).

  The station equipment 10 includes, for example, a video system optical amplifying / distributing device 11 that transmits a downstream video signal having an optical wavelength of 1.55 μm to the main line / support optical cable 20 and a downstream data signal having an optical wavelength of 1.55 μm to the main line / support optical cable 20. And an IP system terminal device 12 that transmits and receives an upstream data signal having an optical wavelength of 1.31 μm from the trunk / supporting optical cable 20 and performs bidirectional data communication.

  The video system optical amplifier / distributor 11 includes an optical transmitter that performs electrical / optical conversion of a frequency-multiplexed video radio frequency (RF) signal, an erbium-doped optical fiber amplifier (EDFA) that amplifies the converted optical video signal, It comprises an optical distributor composed of a plurality of optical couplers for distributing the amplified optical video signal to a number of ONUs (Optical Network Units), and the optical distributor is a trunk / supporting optical cable 20. It is connected to the. Since the IP terminal device 12 is connected to the trunk line / support optical cable 20 and it is necessary to control transmission timing in order to avoid collision of signals from each user in uplink communication, ONU link detection and transmission It has an OLT (Optical Line Terminal) that manages delay and adjusts the transmission start time.

  The trunk / support optical cable 20 has a plurality of cores (for example, 24 cores) of the optical fiber core wire 20-1 for image and the optical fiber core wire 20-2 for data. A closure 30 is connected. The closure 30 includes a one-to-n (1 × n, for example, n = 4) branching image optical coupler 32- connected to one image optical fiber core 20-1 in the trunk line / supporting optical cable 20. 1 and a 1 × n (for example, n = 4) branched data optical coupler 32-2 connected to one data optical fiber core 20-2 in the trunk / support optical cable 20 are accommodated. Yes. The video optical coupler 32-1 branches the video signal in one optical fiber core wire 20-1 into n (four), and n (four) two-core drops at this branch point. Optical fiber core wires 35-1,... In the optical cables 35,. The data optical coupler 32-2 branches the data signal in one optical fiber core wire 20-2 into n (four), and n (four) drop optical cables 35 at the branch point. ,... Are connected to optical fiber core wires 35-2,.

  Each drop optical cable 35 is connected to an FTTH optical connection box 41 attached to each user home 40. In each user's home 40, an image ONU 42 and a data ONU 43 connected to an optical connection box 41 by an optical fiber are installed. The video ONU 42 is a device that is paired with the OLT on the station equipment 10 side, and has an optical / electrical signal conversion function and an optical signal multiplexing / demultiplexing function. For example, a television receiver (hereinafter referred to as “TV receiver”). TV ”) 44 is connected. Similarly, the data ONU 43 is a device that is paired with the OLT on the station equipment 10 side, and has an optical / electrical signal conversion function and an optical signal multiplexing / demultiplexing function. A terminal device 45 such as “PC” or an IP telephone is connected.

  FIG. 7 is a schematic configuration diagram showing details of the drop optical cable closure 30 in FIG.

  The two image optical couplers 32-1 and the data optical coupler 32-2 are disposed on a tray (not shown) mounted in the closure 30.

  One optical fiber core wire 20-1 for video in the trunk line / supporting optical cable 20 is connected to one optical fiber element led out from the incident end of the optical coupler 32-1 for video by a fusion sleeve 31-1. The first, second, third, and fourth optical fiber strands (or optical fiber core wires) that are fusion spliced to the wire (or optical fiber core wire) and led out from the exit end of the optical coupler 32-1. One of (1), (2), (3), and (4) (for example, the fourth optical fiber strand (4)) is 1 by the fusion sleeve 33-4 for 4 channel ch4. The optical fiber core wire 35-1 in the drop optical cable 35 is fused and connected to one end. Further, one optical fiber core wire 20-2 for data in the trunk line / supporting optical cable 20 is provided with one light led out from the incident end of the data optical coupler 32-2 by the fusion sleeve 31-2. First, second, third, and fourth optical fiber strands (a), (b), and (c) that are fusion spliced to the fiber strands and led out from the exit end of the optical coupler 32-2. ), (D) (for example, the fourth optical fiber strand (d)) is bonded to the optical fiber core wire 35 in one drop optical cable 35 by the fusion sleeve 33-4 for the 4-channel ch4. -2, one of the first, second, and third optical fiber strands (1), (2), ( 3) Also, 3 channel ch3 fusion sleeve 33-3, 2 channel ch2 fusion three 33-2, and the first channel ch1 YoToruchaku sleeve 33-1 are respectively fusion-spliced to one end of the other three drop optical cable. Further, the first, second, and third optical fiber strands (a), (b), and (c) led out from the emission end of the optical coupler 31-2 are also fused sleeves 33-3 and 33, respectively. −2, 33-1 are fusion-spliced to one end of the other three drop optical cables.

  The other end of each drop optical cable 35 is connected to the FTTH optical connection box 41 of each user home 40, respectively.

  Next, the operation of the two-core communication system type FTTH-PON system shown in FIGS. 6 and 7 will be described.

  When the downlink video signal time-division multiplexed is output from the video-system optical amplifying / distributing device 11 in the station facility 10, and the downlink data signal time-division-multiplexed is output from the IP system terminal station 12, These downstream video signals and data signals are sent to the user homes 40,... The transmitted downstream video signal and data signal are branched into four video signals by the video optical coupler 32-1 in the closure 30, and the data signal is branched into four by the data optical coupler 32-2. Each branched video signal and each data signal are paired and dropped to the FTTH optical connection box 41,... Of each user home 40,. It is.

  Of the time-division multiplexed video signals and data signals drawn to the optical connection box 41 of each user's home 40, the video signal addressed to itself is separated by the video ONU 42, and then the video is displayed on the TV 44. . In addition, after the data signal addressed to itself is separated by the data ONU 43, the terminal device 45 performs data processing.

  The upstream data signal output from the terminal device 45 is converted into an optical signal by the data ONU 43, and then the station equipment 10 through the FTTH optical connection box 41, the drop optical cable 35, the closure 30, and the trunk / support optical cable 20. Is sent to the internal IP terminal device 12 and reception processing is performed.

  However, the optical couplers 32-1 and 32-2 used in the conventional FTTH-PON system have the following problems (I) to (III).

  (I) As shown in FIG. 7, in the conventional technique, a total of two data optical couplers 32-1 and video optical couplers 32-2 are prepared and mounted in the closure 30. It is arranged on a tray (not shown). Therefore, the cost of the components is doubled, and the space on the tray requires two optical couplers, so it is difficult to reduce the cost and size.

  (II) A plurality of optical fiber strands (or optical fiber core wires) derived from the data optical coupler 32-1 and a plurality of optical fiber strands (or light) derived from the image optical coupler 32-2. The fiber core wire) is wound in an annular shape while securing a predetermined radius for the purpose of securing a surplus length and is accommodated on a tray (not shown) in the closure. For example, the fourth optical fiber strand (4) derived from the video optical coupler 32-1 and the fourth optical five strand (d) derived from the data optical coupler 32-2 are paired. It is necessary to select two of them at the time of construction, but many optical fiber strands (or optical fiber core wires) are wound in a ring and accommodated on the tray. Therefore, the selection is very difficult.

  (III) For example, a user's home 40 has already been laid with a data line, and a video line will be added later, and the video optical coupler 32-1 is not disposed in the closure 30. In this case, a new image optical coupler 32-1 must be provided in the closure 30, and the optical fiber led out from the image optical coupler 32-1 must be routed and accommodated on the tray. ,Take the trouble.

  An optical coupler according to the present invention includes a package having a first opening at one end of a cylindrical shape and a second opening at the other end of the cylindrical shape, and a first coupler portion that is stored in an overlapping manner in the package. And a second coupler part and a sealing material for sealing the first and second openings.

  The first coupler unit is pulled out from the first opening and is connected to the first optical fiber and is stored in the package connected to the first optical fiber. A first branch unit that outputs the first optical signal input by the first optical fiber by n branches (where n is an integer of 2 or more), and is connected to the first branch unit. And n second optical fibers that respectively draw out the n first optical signals drawn from the second opening and outputted from the first branching portion.

  The second coupler unit is a third optical fiber that is paired with the first optical fiber, fixed by the sealing material, pulled out from the first opening, and receives a second optical signal. And the second optical signal connected to the third optical fiber, overlapped with the first branching unit and stored in the package, and n-branched the second optical signal input by the third optical fiber. A second branch part to be output, and a second branch part connected to the second branch part, respectively bundled together with each second optical fiber, and fixed by the sealing material from the second opening part. And n fourth optical fibers that respectively transmit the n second optical signals that are drawn out and output from the second branching unit.

  Here, each of the first, second, third, and fourth optical fibers uses an optical fiber or an optical fiber core wire in which the optical fiber is coated with a coating member. May be.

  The present invention has the following effects (a) to (e).

  (A) Conventionally, when two optical couplers are provided on, for example, a tray mounted in a closure, two optical couplers are necessary. However, in the optical coupler of the present invention, the first and second coupler sections Since it is built in, the number of optical couplers used can be reduced to one. As a result, the number of parts is reduced and the cost can be reduced. Further, since the space on the tray is sufficient for one optical coupler, it can be mounted on various shapes of trays and the like, and the closure including the tray can be downsized.

  (B) The n second optical fibers (or optical fiber strands or optical fiber core wires) drawn from the optical coupler and the n fourth optical fibers (or optical fiber strands or optical fiber core wires) Since two are bundled in pairs, it is very easy to select the two at the time of connection work, and workability is very good.

  (C) For example, in a FTTH-PON system, when a user's home has already been laid with a data line and a video line will be added at a later date, it is necessary to newly add a video optical coupler in the closure There is no. Therefore, it is not necessary to route the optical fiber (or the optical fiber strand or the optical fiber core wire) accompanying the additional installation of the optical coupler. That is, it is only necessary to quickly find one of the paired wires previously routed in pairs and connect the found one of the images to the drop optical cable. Therefore, workability is very good.

  (D) The optical coupler has a relatively simple structure, is easily miniaturized, and is easy to manufacture.

  (E) Since the optical coupler has a bidirectional structure, in addition to the function of branching (demultiplexing) the optical signal, the optical coupler also has a function of multiplexing the optical signal by entering the optical signal from the opposite direction. ing. Therefore, the optical multiplexer / demultiplexer can be used for various other purposes including a closure.

  An optical coupler includes a metal package having a first opening at one end of a cylinder and a second opening at the other end of the cylinder, and a first coupler stored in an overlapping manner in the package. And a second coupler and a sealing material such as an ultraviolet (UV) curable resin that seals the first and second openings.

  The first coupler unit has, for example, a fiber type structure or a waveguide type structure, and is drawn out from the first opening part to output a first optical signal (for example, a video signal for two-core communication). A first optical fiber to be input, and the first optical signal connected to the first optical fiber and housed in the package and input by the first optical fiber is divided into n branches (where n; A first branch portion that is output as an integer greater than or equal to 2 and the n branch portions connected to the first branch portion and drawn out from the second opening portion and output from the first branch portion And n second optical fibers that respectively transmit the first optical signals.

  The second coupler portion has, for example, a fiber type structure or a waveguide type structure, and is paired with the first optical fiber and fixed by the sealing material and pulled out from the first opening portion. And a third optical fiber for inputting a second optical signal (for example, a data signal for two-core communication), connected to the third optical fiber, and overlapped with the first branch portion to form the package. A second branch unit that is n-branched and outputs the second optical signal input by the third optical fiber, and is connected to the second branch unit, Each of the n second optical signals that are bundled together with an optical fiber, fixed by the sealing material, pulled out from the second opening, and output from the second branch, respectively. With n fourth optical fibers to send out To have.

  Instead of this, each of the first, second, third, and fourth optical fibers may use an optical fiber strand or an optical fiber core wire in which the optical fiber is coated with a coating member. .

(Configuration of Example 1)
FIG. 1 is a schematic configuration diagram in the vicinity of a drop optical cable closure in which an optical coupler according to a first embodiment of the present invention is housed.

  This drop optical cable closure 50 is connected to a trunk / support optical cable 20 in place of the closure 30 in the conventional FTTH-PON system shown in FIG. 6, and the trunk / support optical cable 20 is branched by 1 × n to form a two-core drop. It is connected to the FTTH optical connection box 41 of the user home 40 via the optical cable 35.

  On a tray (not shown) mounted in the closure 50, a 2 × 2n type (for example, one for a first optical signal (for example, a video signal) and a second optical signal (for example, a data signal) (for example, An optical coupler 60 with n = 4) is provided. From the incident end of the optical coupler 60, two first optical fiber strands 61-1 for images and a third optical fiber strand 61-2 for data are bundled and led out. From the output end of the optical coupler 60, four pairs of the second optical fiber strand 62-1 for video and the fourth optical fiber strand 62-a for data, and the second optical fiber strand for video A wire 62-2 and a fourth optical fiber strand 62-b for data, a second optical fiber strand 62-3 for video, a fourth optical fiber strand 62-c for data, and a video The second optical fiber strand 62-4 for data and the fourth optical fiber strand 62-d for data are derived. Each optical fiber 61-1,... Has, for example, a structure in which the surface of the optical fiber is covered with a UV curable epoxy resin or the like, and its aperture is, for example, about 125 μm.

  The image optical fiber 62-1 and the data optical fiber 62-a of each pair are bundled so as to be separable and coupled (for example, a two-core tape is coupled). Similarly, the optical fiber for image 62-2 and the optical fiber for data 62-b are combined in a two-core tape, and the optical fiber for image 62-3 and the optical fiber for data 62-c are also combined in a two-core tape. Further, the image optical fiber 62-4 and the data optical fiber 62-d are also combined in a two-core tape.

  The end of the image-forming optical fiber 61-1 is fused and connected to the end of one image-forming optical fiber core 20-1 in the trunk / supporting optical cable 20 by the fusion sleeve 51, and the data The end of the optical fiber 61-2 is fused and connected to the end of one data optical fiber 20-2 in the trunk / supporting optical cable 20 by the fusion sleeve 51. Further, the ends of the paired video optical fiber 62-4 and data optical fiber 62-d are paired with an optical fiber core wire in the drop optical cable 35 by a four-channel ch4 fusion sleeve 52-4. The ends of 35-1 and 35-2 are fused and connected.

  Similarly, the ends of the other pairs of the image optical fiber 62-1 and the data optical fiber 62-a are paired in the other drop optical cables by the 1-channel ch1 fusion sleeve 52-1. The end portions of the optical fiber core wire 62-2 and the data optical fiber strand 62-b are fused and connected to the end portions of the two optical fiber core wires, respectively, by a two-channel ch2 fusion sleeve 52-2. The ends of the two optical fiber core wires in the other drop optical cables are fused and connected, and the end portions of the optical fiber strand for video 62-3 and the optical fiber strand for data 62-c are 3 The channel ch3 fusion sleeve 52-3 is fused and connected to the ends of the two optical fiber core wires in the other drop optical cables.

FIG. 2 is a schematic diagram showing the structure of the 2 × 8 optical coupler 60 in FIG.
The 2 × 8 type optical coupler 60 includes a first coupler unit (for example, a 1 × 4 type video coupler unit) 70-1 and a second coupler unit (for example, a 1 × 4 type data coupler unit) 70. -2 are built in. In the image coupler unit 70-1, one optical fiber strand 61-1 is led out from the incident end, and four optical fiber strands 62-1 to 62-4 are led out from the exit end. . In the data coupler section 70-2, one optical fiber strand 61-2 is led out from the incident end, and four optical fiber strands 62-a to 62-d are led out from the exit end. . The four optical fiber strands 62-1 to 62-4 and the four optical fiber strands 62-a to 62-d are arranged so as to intersect with each other, and the optical fiber strand 62-1 for video and the data Optical fiber strand 62-a, video optical fiber strand 62-2 and data optical fiber strand 62-b, video optical fiber strand 62-3 and data optical fiber strand 62-c , The optical fiber strand for video 62-4 and the optical fiber strand for data 62-d are bundled in one pair, pulled out from the exit end of the optical coupler 60, and combined into a two-core tape. Has been.

  FIGS. 3A and 3B are schematic structural views of a fiber-type optical coupler showing the 2 × 8 optical coupler 60 of FIG. 2, and FIG. 3A is a longitudinal sectional view and FIG. (B) is the II sectional view taken on the line in the figure (a).

  The 2 × 8 optical coupler 60 is a fiber-type optical coupler and has a package 63 made of a cylindrical member (for example, a length of 70 mm and a diameter of about 7 mm) formed of metal or the like. In the package 63, a video coupler unit 70-1 and a data coupler unit 70-2 having the same structure are accommodated in an overlapping manner, and a pair of light beams derived from the coupler units 70-1 and 70-2. The fiber strands 61-1 and 61-2 are pulled out from the first opening of the package 63, and the four pairs of optical fiber strands 62-1 and 62 led out from the coupler portions 70-1 and 70-2. -A to 62-4 and 62-d are drawn out from the second opening of the package 63.

  The video coupler unit 70-1 includes a cylindrical member 71-1 such as a glass tube, and the first branching unit (for example, an end of the optical fiber 61-1 and the like) The optical fiber strands 62-1 to 62-4 are fused to the end portions). Similarly, the data coupler section 70-2 includes a cylindrical member 71-2 such as a glass tube, and the second branch section (for example, the optical fiber strand 61-2) is included in the cylindrical member 71-2. The end portion and the end portion of the optical fiber strands 62-a to 62-d) are inserted.

  The video coupler unit 70-1 and the data coupler unit 70-2 are overlapped and fixed, and the drawn optical fiber strands 61-1 and 61-2 are combined into a two-core tape, The drawn optical fiber strands 62-1, 62-a to 62-4, 62-d are respectively combined into a pair of two-core tapes. The video coupler unit 70-1 and the data coupler unit 70-2 are inserted into the package 63, and the first and second openings at both ends of the package 63 have excellent light transmittance. It is sealed with sealing materials 64-1, 64-2, such as a curable epoxy resin.

(Production example of Example 1)
The optical coupler 60 shown in FIG. 3 is manufactured as follows, for example.
When the video coupler unit 70-1 is manufactured, four long optical fiber strands 61-1, 61-11, 61-12, 61-13 are prepared. A part of the coated portions of the optical fiber strands 61-1, 61-11, 61-12, 61-13 are peeled to bundle the peeled portions, and a burner or the like is applied while applying tension to the peeled portions to the left and right. Then, the ends of the extra three optical fiber strands 61-11 to 61-13 are cut. As a result, a branch structure is formed in which one optical fiber 61-1 is branched by 1 × 4 at the fusion point to become four optical fibers 62-1 to 62-4. After that, if an adhesive or the like is applied to the fused portion and inserted into the cylindrical member 71-1, and then bonded, an image coupler unit 70-1 is obtained.

  When manufacturing the data coupler unit 70-2, the four long optical fiber strands 61-2, 61-21, 61-22, and 61-23 are connected in the same manner as the video coupler unit 70-1. prepare. A part of the coated portions of the optical fiber strands 61-2, 61-21, 61-22, 61-23 are peeled to bundle the peeled portions, and a burner or the like is applied while applying tension to the peeled portions to the left and right. Then, the ends of the extra three optical fiber strands 61-21 to 61-23 are cut. As a result, a branch structure is formed in which one optical fiber 61-2 is branched by 1 × 4 at the fusion point to become four optical fibers 62-a to 62-d. After that, if an adhesive or the like is applied to the fused part and inserted into the cylindrical member 71-2 and bonded, the data coupler part 70-2 is obtained.

  Next, the manufactured image coupler unit 70-1 and data coupler unit 70-2 are overlapped and fixed with an adhesive or the like. The optical fiber 61-1 drawn from the video coupler unit 70-1 and the optical fiber 61-2 drawn from the data coupler unit 70-2 are combined as a two-core tape. . Similarly, optical fiber strands 62-1 to 62-4 drawn from the video coupler unit 70-1 and optical fiber strands 62-a to 62-d drawn from the data coupler unit 70-2. Are respectively formed into a two-core tape in the form of pairs 62-1, 62-a to 62-4, 62-d. In consideration of easy connection and the like, for example, the drawing length of one pair of optical fiber strands 61-1 and 61-2 is 1000 mm or more, and four pairs of optical fiber strands 62-1 and 62-a to 62 It is desirable that the lead-out lengths of −4, 62-d are 1000 mm or more and are color-coded.

  The video coupler unit 70-1 and the data coupler unit 70-2, which are fixed by being overlapped, are inserted into the package 63, and then the first and second openings at both ends of the package 63 are formed into UV curable epoxy. If sealing is performed with sealing materials 64-1 and 64-2 such as resin, the manufacture of the optical coupler 60 in FIG. 3 is completed.

  An example of a method for mounting the optical coupler 60 thus manufactured in the drop optical cable closure 50 of FIG. 1 will be described below.

  One optical coupler 60 is disposed on a tray (not shown) mounted in the closure 50. The incident end portion of the image-forming optical fiber 61-1 led out from one end of the optical coupler 60 is connected to one image-forming optical fiber core wire 20-1 in the trunk / supporting optical cable 20 by the fusion sleeve 51. The incident end portion of the data optical fiber 61-2 led out from one end of the optical coupler 60 is fused and connected to the end portion of the optical fiber 60-6 by the fusion sleeve 51. The data optical fiber core wire 20-2 is fusion spliced. Further, the output end portions of the pair of video optical fiber 62-4 and the data optical fiber 62-d that are paired and led out from the other end of the optical coupler 60 are connected to the fusion sleeve 52 for the 4-channel ch4. -4, the optical fiber core wires 35-1 and 35-2 in the drop optical cable 35 are respectively fused and connected.

  Similarly, the output end portions of the other pairs of the image optical fiber 62-1 and the data optical fiber 62-a are connected to the other drop optical cables by the 1-channel ch1 fusion sleeve 52-1. The ends of the two optical fiber core wires are fused and connected. The optical fiber strand 62-2 for image and the optical fiber strand 62-b for data are connected to the two optical fiber core wires in the other drop optical cable by the fusion sleeve 52-2 for 2 channels ch2. Each of the optical fiber strands 62-3 for data and the optical fiber strands 62-c for data is fused and connected to the end portions, and the other end portions of the optical fiber strands for data 62-c are connected to other ends by a three-channel ch3 fusion sleeve 52-3. The ends of two optical fiber core wires in the drop optical cable are fused and connected. Thereby, the mounting operation of the optical coupler 60 is completed.

(Operation of Example 1)
The operation of the FTTH-PON system of the two-core communication system type shown in FIG. 6 using the optical coupler 60 of the first embodiment will be described.

  6, a time-division multiplexed downlink video signal is output from the video-system optical amplifying / distributing device 11 in the station equipment 10, and a time-division multiplexed downlink data signal is output from the IP-system terminal station device 12. Then, these downstream video signals and data signals are sent to the user homes 40,... The transmitted downstream video signal and data signal are sent to the optical fiber core wire 20-1, the optical fiber core wire 20-2 for data, the fusion sleeve 51, and the optical fiber element in the closure 50 shown in FIGS. The signal is input to the optical coupler 60 via the lines 61-1 and 61-2. The video signal and the data signal input to the optical coupler 60 are branched into four by the video coupler unit 70-1 and the data coupler unit 70-2, respectively, and 1 through the optical fiber strands 62-1 to 62-4. Channel ch1 fusion sleeve 52-1 to 4 channel ch4 fusion sleeve 52-4 are respectively transmitted. The transmitted video signal and data signal are paired with the optical fiber cores 35-1, 35-2,... In the drop optical cable 35,. It is pulled down to the optical connection box 41.

  Of the time-division multiplexed video signal and data signal that have been pulled down to the optical connection box 41 of a user's home 40, the video signal addressed to the user is separated by the video ONU 42 and converted into an electrical signal, and then to the TV 44. The video is displayed. In addition, the data signal addressed to itself is separated by the data ONU 43 and converted into an electrical signal, and then sent to the terminal device 45 to perform predetermined data processing.

  The upstream data signal output from the terminal device 45 is converted into an optical signal by the data ONU 43, and then the FTTH optical connection box 41, the optical fiber core wires 35-1 and 35-2 in the drop optical cable 35, and the closure 50. Fusion sleeve 52-4, optical fiber strands 62-4, 62-d, video coupler portion 70-1, optical coupler portion 70-2 in optical coupler 60, optical fiber strands 61-1, 61- 2, the IP terminal device in the station equipment 10 of FIG. 6 via the fusion sleeve 51, the optical fiber core wire 20-1 for video in the trunk / supporting optical cable 20, and the optical fiber core wire 20-2 for data. 12 for reception processing. In this way, bidirectional data communication is performed between the station facility 10 and the user home 40.

(Effect of Example 1)
According to the first embodiment, the following effects (a) to (e) are obtained.

  (A) Since the optical coupler 60 disposed on the tray (not shown) mounted in the closure 50 includes the video coupler unit 70-1 and the data coupler unit 70-2, the number of optical couplers used Can be made one. As a result, the number of parts is reduced and the cost can be reduced. Furthermore, since the space on the tray is sufficient for one optical coupler, it can be mounted on various shapes of trays, etc., and the closure 50 including the tray can be downsized.

  (B) The optical fiber strands 62-1 to 62-4 for video and the optical fiber strands 62-a to 62-d for data drawn out from the optical coupler 60 are paired two by two to form a two-core tape. Since they are combined and combined, it is very easy to select the two at the time of connection work, and workability is very good.

  (C) For example, when a user's home 40 has already been laid with a data line and a video line is added later, there is no need to newly add a video optical coupler in the closure 50. Therefore, of course, it is not necessary to route the optical fiber (or the optical fiber core wire) when the optical coupler is additionally provided. That is, one of the pair wires (for example, optical fiber strands 62-4 and 62-d) previously routed in a pair can be found immediately (image optical fiber strand 62-d). The optical fiber strand 62-d for use and one optical fiber core wire (image optical fiber core wire 35-1) in the drop optical cable 35 need only be fused by the fusion sleeve 52-4. Therefore, workability is very good.

  (D) As shown in FIG. 3, the fiber type optical coupler 60 has two coupler sections having the same structure, one of which is the video coupler section 70-1 and the other is the data. Used as the coupler section 70-2, the two coupler sections 70-1 and 70-2 are overlapped and inserted into the cylindrical package 63, and the derived optical fiber strands 61-1 and 61- 2 is paired into a two-core tape and combined, and the derived optical fiber strands 62-1 to 62-4 and 62-a to 62-d are paired into a two-core tape and combined, Since both ends of the package 63 are sealed with the sealing materials 64-1 and 64-2, the structure is relatively simple, easy to downsize, and easy to manufacture. Therefore, the fiber-type optical coupler 60 of the first embodiment is small in size, has good connectivity with the optical fiber, easily ensures reliability, and is suitable for diversity.

  (E) Since the fiber type optical coupler 60 of FIG. 3 has a bidirectional structure, in addition to the function of branching (demultiplexing) the optical signal, the optical signal is combined by entering the optical signal from the opposite direction. It also has a function to wave. Therefore, the optical multiplexer / demultiplexer can be used for various other purposes including the closure 50.

(Configuration of Example 2)
4A to 4D are schematic structural views of a waveguide type optical coupler showing the 2 × 8 type optical coupler 60 of FIG. 2, and FIG. 4A is a transverse sectional view, FIG. (b) is a longitudinal sectional view, FIG. (c) is a sectional view taken along line II-II in FIG. (b), and FIG. (d) is a sectional view taken along line III-III in FIG. In FIG. 4, elements common to the elements in FIG. 3 illustrating the first embodiment are denoted by common reference numerals.

  The 2 × 8 optical coupler 60A is a waveguide fiber type optical coupler and is made of a rectangular tube-shaped member (for example, 55 mm in length, 4 mm in length and 7 mm in width). A package 63A is provided. The package 63A includes a storage member 63A-1 having a U-shaped cross section and a lid member 63A-2 having a U-shaped cross section that closes an opening in the longitudinal direction of the storage member 63A-1. In the storage member 63A-1, a first coupler portion (for example, a prismatic 1 × 4 image coupler portion) 70A-1 and a second coupler portion (for example, a prismatic shape having the same structure as this) are provided. 1A.times.4 type data coupler part) 70A-2 are stored in an overlapping manner, and a lid member 63A-2 is fitted into the opening in the longitudinal direction of the storage part 63A-1.

  The video coupler unit 70A-1 is joined to a first branching unit (for example, an optical waveguide with one incident and four outputs) 71A-1 and an incident end face of the optical waveguide 71A-1, and is connected to the first optical five strand. An optical fiber fixing member 72-1 for receiving and fixing the end portion of 61-1 in the groove portion, and four second optical fiber strands joined in parallel to the emission end face of the optical waveguide 71A-1. It is comprised by the optical fiber fixing member 73-1 which accommodates and fixes the edge part of 62-1 to 62-4 in a groove part. Similarly, the data coupler unit 70A-2 is joined to the second branching unit (for example, one incident four-emission optical waveguide) 71A-2 and the incident end face of the optical waveguide 71A-2, so that the third light An optical fiber fixing member 72-2 that accommodates and fixes the end of the five strand 61-2 in the groove, and four fourth lights that are joined to the emission end face of the optical waveguide 71A-2 and arranged in parallel. It is comprised by the optical fiber fixing member 73-2 which accommodates and fixes the edge part of fiber strand 62-a-62-d in a groove part.

  The video coupler unit 70A-1 and the data coupler unit 70A-2 are overlapped and fixed in the package 63A. The upper and lower optical fiber strands 61-1 and 61-2 led out from the coupler portions 70A-1 and 70A-2 are combined in a pair of two-core tapes, and are connected from the first opening of the package 63A. Has been pulled out. Furthermore, the upper and lower optical fiber strands 62-1, 62-a to 62-4, 62-d led out from the coupler sections 70A-1 and 70A-2 are each formed into a two-core tape in the form of a pair. And are pulled out from the second opening of the package 63A. The first and second openings at both ends of the package 63A are sealed with sealing materials 64A-1 and 64A-2 such as UV curable epoxy resin.

(Production example of Example 2)
The optical coupler 60A shown in FIG. 4 is manufactured as follows, for example.
For example, in the case of the buried structure, the optical waveguide 71A-1 constituting the video coupler unit 70A-1 has a lower clad layer formed on a substrate such as a silicon substrate, and the light transmissive property on the lower clad layer. A core layer made of an excellent UV curable epoxy resin or the like is selectively formed by etching or the like, and the core layer is further covered with an upper cladding layer. For example, the optical fiber fixing members 72-1 and 73-1 have grooves formed on a substrate such as a silicon substrate by etching or the like, and the optical fiber strands 61-1, 62-1 to 62-4 are formed in the grooves. Are fixed with an adhesive or the like, and then aligned (aligned) with the end surface of the optical waveguide 71A-1 to be bonded to form the video coupler portion 70A-1.

  Similarly to the video coupler unit 70A-1, when the data coupler unit 70A-2 is manufactured, the buried type optical waveguide 71A-2 and the optical fiber strands 61-2, 62-a to 62- The optical fiber fixing members 72-2 and 73-2 with the ends of d fixed are formed. Thereafter, if the optical fiber fixing members 72-2 and 73-2 are aligned (aligned) and bonded to the end face of the optical waveguide 71A-2, the data coupler portion 70A-2 can be formed.

  Next, the manufactured image coupler unit 70A-1 and data coupler unit 70A-2 are superposed and bonded together. The upper and lower optical fiber strands 61-1 and 61-2 derived from the coupler units 70A-1 and 70A-2 are combined in a pair of two-core tapes, and the coupler units 70A-1 and 70A-2 are combined. The upper and lower optical fiber strands 62-1, 62-a to 62-4, 62-d derived from the above are also combined into a two-core tape in the form of a pair of upper and lower. The bonded video coupler unit 70A-1 and data coupler unit 70A-2 are fixed in the housing member 63A-1 of the package 63A, and the upper and lower pairs of optical fiber strands 61-1 and 61-2 are accommodated. The optical fiber strands 62-1, 62-a to 62-4, 62-d of the upper and lower pairs are pulled out from the other end of the housing portion 63A-1.

  In the same manner as in the first embodiment, in consideration of easy connection and the like, for example, the drawing length of one pair of optical fiber strands 61-1 and 61-2 is 1000 mm or more, and four pairs of optical fiber strands 62- The lead-out lengths of 1,62-a to 62-4,62-d are desirably 1000 mm or more and are color-coded.

  A lid member 63A-2 is fitted into the opening in the longitudinal direction of the storage portion 63A-1 to fix the package 63A. Then, if the first and second openings at both ends of the package 63A are sealed with sealing materials 64A-1 and 64A-2 such as UV curable epoxy resin, the manufacture of the optical coupler 60A of FIG. 4 is completed. To do.

  The optical coupler 60A thus manufactured is mounted in the drop optical cable closure 50 of FIG. 1 by the same method as in the first embodiment.

(Operation of Example 2)
The operation of the FTTH-PON system of the two-core communication system type shown in FIG. 6 using the optical coupler 60A of the second embodiment is the same as that of the first embodiment.

(Effect of Example 2)
According to the second embodiment, there are the same effects as the effects (a) to (c) of the first embodiment, and further, there are the following effects (i) and (ii).

  (I) The waveguide type optical coupler 60A has two coupler sections having the same structure, one of which is a video coupler section 70A-1, and the other is a data coupler section 70A-2. The two coupler portions 70A-1 and 70A-2 are overlapped and mounted in a rectangular tube-shaped package 63A, and then both end openings of the package 63A are sealed with sealing materials 64A-1 and 64A-2. Since the structure is sealed with, the structure is relatively simple and easy to manufacture. In particular, the waveguide type optical coupler 60A according to the second embodiment can be reduced in size, easily combined, and suitable for mass production as compared with the fiber type optical coupler 60 according to the first embodiment.

  (Ii) Since the waveguide type optical coupler 60A has a bidirectional structure, in addition to the function of branching (demultiplexing) the optical signal, the optical signal is multiplexed by entering the optical signal from the opposite direction. It also has a function. Therefore, the optical multiplexer / demultiplexer can be used for various other purposes including the closure 50.

(Modification)
The present invention is not limited to the above-described embodiments, and various usage forms and modifications are possible. For example, the following forms (a) to (c) are available as usage forms and modifications.

  (A) FIG. 5 is a schematic diagram of the structure of a 2 × 16 optical coupler showing a modification of the 2 × 8 optical coupler 60 of FIG.

  The 2 × 16 type optical coupler 60B includes a first coupler unit (for example, 1 × 8 type video coupler unit) 70B-1 and a second coupler unit (for example, 1 × 8 type data coupler unit) 70B−. 2 are built in one package. When such an 8-branch type optical coupler 60B is used, wiring to 8 user homes 40,... Is possible. The optical coupler of the present invention can be applied to any number of branches.

  (B) The optical fiber strands 61-1, 61-2, 62-1, 62-a to 62-4, 62-d may be replaced with optical fiber core wires or optical fibers. good.

  (C) The optical couplers 60 and 60A of the first and second embodiments can be changed to shapes, structures, manufacturing methods and the like other than those shown in the drawings, and the FTTH-PON system having other configurations than those shown in the drawings and various other types are available. Can be used for applications.

It is a schematic block diagram of the vicinity of the closure for the drop optical cable in which the optical coupler showing Embodiment 1 of the present invention is housed. It is a schematic diagram which shows the structure of the 2 * 8 type optical coupler 60 in FIG. FIG. 3 is a schematic structural diagram of a fiber type optical coupler showing the 2 × 8 type optical coupler 60 of FIG. 2. FIG. 3 is a schematic structural diagram of a waveguide type optical coupler showing the 2 × 8 type optical coupler 60 of FIG. 2. FIG. 5 is a schematic diagram of a structure of a 2 × 16 type optical coupler showing a modification of the 2 × 8 type optical coupler 60 of FIG. 2. It is a schematic block diagram of the conventional FTTH-PON system of a two-core communication system type. It is a schematic block diagram which shows the detail of the closure 30 for drop optical cables in FIG.

Explanation of symbols

20 trunk / branch optical cable 35 drop optical cable 50 closure 60, 60A, 60B optical coupler 61-1, 61-2, 62-1, 62-a to 62-4, 62-d optical fiber 63, 63A package 64- 1, 64A-1, 64-2, 64A-2 Sealing material 70-1, 70A-1, 70B-1, 70-2, 70A-2, 70B-2 Coupler part

Claims (6)

A package having a first opening at one end of the tube and a second opening at the other end of the tube;
A first coupler section and a second coupler section which are stored in an overlapping manner in the package;
An optical coupler comprising a sealing material for sealing the first and second openings,
The first coupler unit includes:
A first optical fiber that is drawn from the first opening and receives a first optical signal;
The first optical signal connected to the first optical fiber, housed in the package, and input by the first optical fiber is n-branched (where n is an integer of 2 or more) and output. A first branch,
N second light beams connected to the first branch portion and drawn out from the second opening portion and respectively output the n first optical signals output from the first branch portion. With fiber,
The second coupler unit includes:
A third optical fiber which is paired with the first optical fiber and is fixed by the sealing material and pulled out from the first opening to input a second optical signal;
Connected to the third optical fiber, overlapped with the first branching section, accommodated in the package, and n-branched and output the second optical signal input by the third optical fiber A second branch,
Connected to the second branch portion, bundled together with each second optical fiber, fixed in place by the sealing material, and pulled out from the second opening portion, respectively, the second branch portion And n fourth optical fibers that respectively transmit the n second optical signals output from the optical coupler.   2. The optical coupler according to claim 1, wherein the first and second branch portions have a fiber type structure or a waveguide type structure.   3. The optical coupler according to claim 1, wherein the package is formed of a cylindrical member or a rectangular tube member.   The optical coupler according to claim 1, wherein the sealing material is an ultraviolet curable resin. The optical coupler according to any one of claims 1 to 4,
In place of each of the first, second, third and fourth optical fibers, an optical fiber strand or an optical fiber core wire in which the optical fiber is covered with a covering member is used. Optical coupler.   6. The first optical signal is a video signal for two-core communication, and the second optical signal is a data signal for two-core communication. The optical coupler described in 1.

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