JPH0943450A - Optical branching unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optical branching unit made higher in density to 2N fibers (N is >=4) from 4 fibers without changing sizes by specifying the number of coated fiber ribbons to be connected to both sides of a waveguide type optical coupler module having 2N pieces of coupler functions to N pieces per side. SOLUTION: The waveguide type optical coupler module 63 having eight pieces of coupler functions is used for the optical branching unit 61 the four-fiber coated fiber ribbons 25A, 25B are connected to the one side of this module and the four coated fiber ribbons 31A, 31B are connected to the opposite side thereof, thereby constituting communication ports on an extra-office side an intra-office side together with optical connectors. The four-fiber coated fiber ribbons 39A, 39B, 35A, 35B connected to the one side and the opposite side of the module 63 constitute their respective one-side test ports and the other-side test ports. The coated fiber ribbons connected to the module 63 are all the four-fiber coated fiber ribbons if the optical branching unit is constituted in such a manner and therefore, the space for housing the extra lengths thereof and the space for housing the optical connectors at their front ends is eventually necessitated to be the same as heretofore.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical branching unit for adding an optical inserting / branching function to an optical communication line to enable line testing or monitoring.

[0002]

2. Description of the Related Art An example of using an optical branching unit is shown in FIG. The optical branching unit 11 is installed between the in-station optical cable and the out-of-station optical cable. Reference numeral 13 is a tape core wire (tape-shaped multi-core optical fiber core wire) of the outside optical cable, 15 is a multi-core optical connector attached to its end, 17 is a single core optical fiber core wire of the intra-office optical cable, and 19 is its end. It is a single-fiber optical connector attached to the section.

The optical branching unit 11 includes a waveguide type optical coupler module 21 in which a plurality of optical couplers are integrated on the same chip, a multi-core optical connector 23 and a tape core wire 25 which constitute a communication port on the outside of the station. The single-core optical connector 27, the single-core optical fiber core wire 29, and the tape core wire 31 that form the communication port inside the station, the multi-core optical connector 33 and the tape core wire 35 that form the first test port, and the second The multi-core optical connector 37 and the tape core wire 39 which constitute the test port of 1.

A test device 49 is connected to the multi-fiber optical connectors 33 and 37, which are the first and second test ports, via the multi-fiber optical connectors 41 and 43 and the tape core wires 45 and 47. The tape core wire 13 of the outside optical cable and the single core optical fiber core 17 of the inside optical cable are connected via a coupler of the waveguide type optical coupler module 21 to form a communication line. When testing the line, test light is inserted from the test device 49 through the coupler, and the reflected light is branched to measure the loss, the failure point, or the like.

The above is an example of use of the optical branching unit.
A conventional optical branching unit of this type is configured as shown in FIGS. 6 and 7. 6 and 7, the same parts as those in FIG. 5 are designated by the same reference numerals. That is, the light branching unit 11 is housed in the flat case 51. The inside of the case 51 is divided into a first space 55 and a second space 57 by an intermediate partition plate 53 as shown in FIG. The extra space of the tape core wires 25, 31, 39, 35 coming out from the waveguide type optical coupler module 21 is accommodated in the first space 55, and the optical connector 23 serving as a communication port and the test port are accommodated in the second space 57. The optical connectors 33 and 37 are stored.

In the conventional optical branching unit 11, the waveguide type optical coupler module 21 has four coupler functions, and the number of tape cores is four. The tape core wire is protected by a nylon tube. With this structure, the conventional optical branching unit has a thickness of 10.5 mm.

[0007]

In order to increase the density of the conventional structure, a waveguide type optical coupler module having 2N (N is 4 or more) coupler functions is used, and the waveguide type optical coupler module is used. When the tape core wire is made into two 2N core tape core wires, the first space 55 for accommodating the extra length of the tape core wire by the width of the 2N core tape core wire is wider than the width of the four core tape core wire 55. Must be increased. Therefore, the optical branching unit using the waveguide type optical coupler module having 2N coupler functions is thicker than the optical branching unit using the four waveguide type optical coupler modules having the coupler function. It was

Since the optical branching units are used by arranging them in units of several tens on each stage of the rack, when the thickness of the optical branching unit increases, the number of optical branching units that can be stored in one stage of the rack decreases. For this reason, even if the number of couplers of the waveguide type optical coupler module is increased and the density of the optical branching unit is increased, there is a problem that the effect cannot be fully utilized as a rack.

An object of the present invention is to provide an optical branching unit having a high density from 4 cores to 2N cores without changing the size of the optical branching unit.

[0010]

The optical branching unit of the present invention comprises a waveguide type optical coupler module in which 2N (N is 4 or more) optical couplers are integrated on the same chip and one communication port. It is equipped with two N-core optical connectors, 2N single-core optical connectors that compose the other communication port, and two sets of 2N-core optical connectors that compose the test port, and are provided on both sides of the waveguide type optical coupler module. Is characterized in that N tape core wires connected to the respective optical connectors are connected to each other.

When the waveguide type optical coupler module having 2N coupler functions is used as described above, the number of tape cores connected to both sides of the waveguide type optical coupler module is N on each side. Thereby, it becomes possible to use the tape core wire having the same width as the conventional one. Therefore, it is possible to realize an optical branching unit having the same size as the conventional one and having 2N coupler functions.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. 1 to 3 show an embodiment of the present invention. The optical branching unit 61 uses eight waveguide type optical coupler modules 63 having a coupler function.

25A and 25B are two four-core tape core wires whose one ends are connected to one side of the waveguide type optical coupler module 63, and 23A and 23B are attached to the other ends of the four-core tape core wires 25A and 25B. Two 4-core optical connectors, which constitute a communication port outside the station. 31A, 31B
Is two two-core tape core wires whose one ends are connected to the opposite side of the waveguide type optical coupler module 63, 29 is eight single-core optical fiber core wires branched from the four-core tape core wires 31A and 31B, 27 Are eight single-core optical connectors attached to the tip of the single-core optical fiber 29, and these constitute communication ports inside the station.

Reference numerals 39A and 39B are two four-core tape core wires whose one ends are connected to one side of the waveguide type optical coupler module 63, and 37A and 37B are a set of two 8-core optical connectors, and these are one of them. Configures the test port. 35A, 35
B is two four-core tape core wires whose one end is connected to the opposite side of the waveguide type optical coupler module 63, and 33A and 33B are two.
One set of 8-fiber optical connectors, which constitute the other test port.

With this structure, all the tape cores connected to the waveguide type optical coupler module 63 are four cores, so that the first space 55 (see FIG. 2) for accommodating the extra length is The optical connector attached to the tip of each tape core wire may be the same as the conventional one, and the second space 57 (see FIG. 2) for housing them may be the same as the conventional one. Therefore, the thickness of the case 51 may be 10.5 mm, which is the same as the conventional case. In FIG. 2, numeral 53 is an intermediate partition plate. Further, in FIG. 1, 13A and 13B are four-core tape core wires on the outside optical cable side, and 45A and 45B are four-core tape core wires on the test apparatus side.

When the above structure is adopted, the case 5
Since the number of the tape core cords introduced in 1 increases, unless the density of the retaining portions of the tape core cords is increased, the space for storing the extra length of the tape core cords becomes narrow and the required bending radius cannot be secured. There is a risk. In order to solve this problem, a retaining structure as shown in FIG. 4 may be adopted.

In FIG. 4, 45A and 45B are four-core tape core wires on the test apparatus side, 45A1 and 45B1 are cords containing the tape core wires 45A and 45B, and 45A2 and 45B2.
Is a retaining block for cords 45A1 and 45B1, 45
A3 and 45B3 are pipes for fixing the tensile strength fibers of the cords 45A1 and 45B1 to the retaining blocks 45A2 and 45B2. 65 is a retaining block 45A.
Case for holding 2, 45B2 (see FIGS. 1 and 2).
No. 51).

The holder 65 is a retaining block 45A.
Instead of gripping the peripheral surface of 2,45B2,
It is designed to be gripped at two points (two points on each side).
In this way, the retaining blocks 45A2, 45B2
Since the cords can be arranged close to each other, there is an advantage that the cord retaining portions can be made denser (smaller).

[0019]

As described above, according to the present invention, 2
An optical branching unit using a waveguide type optical coupler module having N (N is 4 or more) coupler functions has
The size of the optical branching unit can be about the same as that of the optical branching unit using the waveguide type optical coupler module having the individual coupler function, and a remarkable effect can be obtained in increasing the density of the optical branching unit.

[Brief description of drawings]

FIG. 1 is a plan view of an optical branching unit according to an embodiment of the present invention.

FIG. 2 is a sectional view of the optical branching unit of FIG.

FIG. 3 is a development explanatory view of the optical branching unit of FIG. 1.

FIG. 4 is a plan view showing a structure of a retaining portion of a tape cable cord in the optical branching unit of FIG.

FIG. 5 is a development explanatory diagram showing a usage state of a conventional optical branching unit.

FIG. 6 is a plan view of a conventional optical branching unit.

7 is a cross-sectional view of the optical branch unit of FIG.

[Explanation of symbols]

23A, 23B: 4-fiber optical connector (outside communication port) 25A, 25B: 4-fiber ribbon core 27: Single-fiber optical connector (internal communication port) 29: Single-fiber optical fiber 31A, 31B: 4-fiber tape Core wires 33A, 33B: Two cores of four-core optical connector (test port) 35A, 35B: Four-core tape core wire 37A, 37B: Two pairs of four-core optical connector (test port) 39A, 39B: 4 Core tape Core wire 51: Case 53: Intermediate partition plate 55: First space 57: Second space 61: Optical branching unit 63: Waveguide type optical coupler module having eight coupler functions

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Takeo Shimizu 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Innovator Nobuo Tomita 1-1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corp. (72) Inventor Naoyuki Atobe 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corp.

Claims (1)

[Claims] 1. A waveguide type optical coupler module in which 2N (N is 4 or more) optical couplers are integrated on the same chip, two N-core optical connectors constituting one communication port, and communication of the other. 2N single-core optical connectors forming ports and two sets of 2N-core optical connectors forming test ports,
An optical branching unit characterized in that N tape core wires connected to the respective optical connectors are respectively connected to both sides of the waveguide type optical coupler module.