JPH0253341A - Optical multiplexing branching device and optical communication system - Google Patents

Abstract

PURPOSE:To flexibly correspond to the expansion of a system, etc., by using an optical multiplexing branching device to define an (n)-number of the optical signals of a different wavelength and to have the (n)-number of branching outputs and plural synthetic outputs and constructing an optical communication system. CONSTITUTION:The optical signals of wavelengthes lambda1-lambda4 are respectively inputted from input terminals 100-103 and supplied to two-branching devices 15-18. One of the optical signals of the wavelengthes lambda1lambda4 to be branched by the two- branching devices 15-18 are respectively outputted from output terminals 104-107 and the other part of the signals are supplied to an optical coupler 27. In the optical coupler 27, the optical signals of the wavelengthes lambda1-lambda4 to be supplied from waveguide paths 23-26 are synthesized and after that, branched to the four signals and the optical signals of the wavelengthes lambda1-lambda4 are outputted from output terminals 108-111 in a multiplexed form. Thus, by using one multiplexing branching device, the optical signal to be multiplexed from a trunk line system to four subscribers can be branched.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an optical communication system that transmits information such as video, audio, various data, etc. by optical signals using optical fiber cables, and an optical multiplexing/branching device used therein. It is related to.

Conventional technology In recent years, optical communication systems using optical fibers have been making remarkable progress with the reduction of loss in optical fibers and advances in optical devices.
The transmission of large amounts of data such as signals is also progressing steadily. In addition, due to significant cost reductions in optical fiber cables, optical devices, etc., the use of optical fibers has begun to be considered not only between core stations but also between subscriber systems, and some CATV networks are already using optical fibers for large-capacity optical transmission. Transmission services for television images, etc. are provided by

An example of the above-mentioned conventional optical communication system will be described below with reference to the drawings.

FIG. 4 shows the configuration of a conventional optical communication system. In Fig. 4, 51 is a terminal station, 52.53°55,
56.58 is an optical splitter, 54.57 is an optical repeater,
Each is connected by fiber optic cables, forming a star-shaped network.

The operation of the optical communication system constructed as described above will be explained below.

An optical signal with a wavelength λ sent out from the terminal station is branched by a splitter 52 and a splitter 53, and transmitted to each subscriber's home as an optical signal with a wavelength λ. The optical signal attenuated by branching is waveform-shaped and amplified in the repeater 54, and then sent to the brancher 5 again.
5.56.58, the signal is branched to each subscriber's home, and a portion of the signal is waveform-shaped and amplified in the optical repeater 57 before being transmitted.

Problems to be Solved by the Invention However, in the above configuration, the amount of information transmitted to each subscriber is only information transmitted by an optical signal of wavelength λ, and it is difficult to transmit a digitized high-definition television signal. In this case, the bit rate will be about 1.3 Gbps, and current technology is limited to at most one channel transmission. Furthermore, although it is possible to increase the number of channels by increasing the number of optical fibers, the number of optical fibers attached to the subscriber system also increases by the number of channels, which makes the cost extremely expensive. However, the problem is that the system as a whole becomes large-scale, making it difficult to secure space for installation.

In view of the above problems, the present invention provides an optical communication system that can transmit multiple channels of video signals with a large amount of information, such as high-definition TV signals, without increasing the number of optical fibers installed in the subscriber system, and an optical multiplexing branch used therein. It provides equipment and equipment.

Means for Solving the Problems In order to solve the above problems, the optical multiplexer/brancher of the present invention has the following features:
n optical signal input terminals with different wavelengths (n=2.3,
), the device has a branching output terminal for the optical signals having the different wavelengths, and a multiplexing output terminal for the optical signals having the different wavelengths.

Further, in the optical communication system of the present invention, optical signals having different wavelengths are inputted to the n optical signal input terminals of the optical multiplexing/branching device, and the n wavelengths of the optical multiplexing/branching device are in phase with each other. Branch output terminals for different optical signals are each connected to an optical repeater having n input/output systems, and the optical repeater outputs an optical signal having the same wavelength as the input.

Effect The present invention uses optical signals of different wavelengths to transmit a plurality of channels of high-quality TV signals through a plurality of optical fibers, and uses the above-described optical multiplexing/branching device to connect the plurality of optical fiber cables. The optical signals with different wavelengths that are manually generated are multiplexed and branched and output to the subscriber system, and the branched output of the optical signals with different wavelengths is sent to other optical multiplexers or optical repeaters as a trunk network. will be connected to the network, forming a star-shaped network as a whole.

With this configuration, each subscriber's home can receive a plurality of signals transmitted by optical signals with different wavelengths through a single optical fiber cable.

EXAMPLE Hereinafter, an optical multiplexer/brancher according to an example of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of an optical multiplexer/brancher in a first embodiment of the present invention. In Figure 1, 1). 12.131.4.19.20.
21. , 22.23.24.25.26.28.29゜30, 31 is an optical waveguide, 15.16.17.18 is a 2-brancher, 27 is an optical coupler, and 32 is the entire optical multiplexer/brancher. Indicates a block, 100. 101. 102.
103 is an input terminal for four different wavelength optical signals;
4. 105, 106, 107 are branch output terminals for the optical signals having different wavelengths; 108. 109. 1) 0.
1) 1 is a multiplexing output terminal for the optical signals having different wavelengths.

The operation of the optical multiplexer/brancher configured as described above will be explained below with reference to FIGS. 1 and 2.

Wavelength λ direct, λ2. λ3. The optical signals of λ4 are respectively input to input terminals 100. 101. 102. 103 and is supplied to two branchers 15, 16, 17, and 18. 2
The wavelengths λ1゜λ2 . λ1. One of the optical signals of λ4 is output to the output terminal 104. 105. 106. 107, and the other is supplied to the optical coupler 27. In the optical coupler 27, the wavelength λ is supplied from the waveguides 23, 24, 25, and 26.

λ2. λ3. After the optical signal of λ4 is multiplexed, it is branched into four signals and sent to an output terminal 108. 109. 1) 0. 1) Wavelength λ1 from 1. λ2. λ3. The optical signal of λ4 is output in a multiplexed form.

As described above, according to this embodiment, it is possible to obtain four systems of outputs by combining optical signals of four wavelengths, and as an output to the trunk system, wavelengths λ1, . λ2.
λ3. It also has a λ4 optical signal output. Therefore, by using one of the present multiplexing/branching devices, optical signals multiplexed from the main line to four subscribers can be branched.

A second embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a block diagram of a multiplexing branch showing a second embodiment of the present invention. In the same figure, 35.36.3
7.・38 is a 4-brancher, 39.40 is an optical coupler,
33 indicates the entire block of this multiplexing branch. Unlike the first embodiment, it consists of two 4-branchers and two optical couplers, and eight optical signal multiplexing output terminals and wavelength 'l+λ2. λ1.
It has two systems of output terminals for the λ4 optical signal for the trunk system.

According to the multiplexing/branching device of this embodiment, the trunk system can be branched into two systems, and the number of multiplexing output terminals for subscriber systems can be further increased compared to the first embodiment.

A third embodiment of the present invention will be described below with reference to the drawings. FIG. 3 shows the configuration of an optical communication system showing a third embodiment of the present invention.

In Figure 3, 41 is a terminal station, 42.43.46.47
45 is the optical multiplexing/branching device explained in the first embodiment;
The optical multiplexing/branching device 44 and 48 described in the embodiment are optical repeaters with four input and output systems that output light with the same wavelength as the human wavelength, and each transmits optical signals with wavelengths λ1 to λ4. The network is connected by 4H optical fiber, forming a star-shaped network.

The operation of the optical communication system configured as follows will be explained below.

Wavelength λ1~ transmitted from the terminal station through four optical fibers
The optical signal of λ4 is branched into four optical fibers in which the optical signals of each wavelength are multiplexed at the optical multiplexing/branching device 42 and supplied to the subscriber system, and the optical signals of the branched wavelengths λ to λ4 are The signal is supplied to an optical multiplexing/branching device 43 through a main optical fiber, and after being similarly branched, it is supplied to an optical repeater 44 . Optical repeater 4
4, each optical signal of each wavelength λ1 to λ4 is waveform-shaped and amplified, and then outputted as an optical signal of the same wavelength as the input, and supplied to the multiplexer/brancher 45. In the multiplexing/branching device 45, the optical signals of each wavelength are multiplexed and outputted to four optical fibers, and are supplied to the subscriber system.
The set of branched outputs are sent to optical multiplexers 46 and 4, respectively.
Supply to 7. Optical multiplexing/branching devices 46 and 47 operate in the same manner as multiplexing/branching devices 42 and 43, and the optical repeater 44 operates in the same manner as the optical repeater 44, and supplies optical signals to subscriber systems in a star-shaped network as a whole. .

As described above, in this embodiment, the trunk system uses four optical fibers to carry optical signals of different wavelengths for relay transmission, and an optical multiplexer/brancher is used to transmit the optical signals of each wavelength. By combining the signals and supplying them to the subscriber system, it is possible to transmit four times as much information without increasing the number of optical fibers installed to each subscriber's home.

Effects of the Invention As described above, the present invention provides an optical communication system using an optical multiplexing/branching device that receives 0 optical signals with different wavelengths as input and has 0 branching outputs and multiple multiplexing outputs. By constructing the Since no optical demultiplexer or the like is used, the wavelength to be used can be freely set, and the system can be flexibly expanded.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an optical multiplexer/brancher in a first embodiment of the present invention, FIG. 2 is a block diagram of an optical multiplexer/brancher in a second embodiment of the present invention, and FIG. 3 is a block diagram of an optical multiplexer/brancher in a second embodiment of the present invention. FIG. 4 is a block diagram of a conventional optical communication system. 15, 16.17.18...2 branch, 27.
...Optical coupler, 35, 36.37.38...
... 4-brancher, 39.40... Optical coupler, 41
...Terminal, 42.43.4 Fake 46.47...
... Optical multiplexing branch, 44.48 ... Repeater, 51 ... Terminal, 52°53, 55.56.5
8... Optical splitter, 54.57... Optical repeater. Name of agent: Patent attorney Shigetaka Awano. '1)? Nbi? Nnnnnnn bag law service also

Claims (4)

[Claims] (1) N optical signal input terminals with different wavelengths (n=2,
3,...), a branching output terminal for the optical signals having different wavelengths, and a multiplexing output terminal for the optical signals having different wavelengths. (2) n optical signal input terminals with different wavelengths are respectively connected to n m branchers, (m=2, 3,...) the n
2. The optical multiplexing/branching device according to claim 1, wherein at least one output of each of the m branching devices is connected to an n-input optical coupler. (3) An optical communication system characterized in that optical signals having different wavelengths are input to the n optical signal input terminals of the optical multiplexing/branching device according to claim (1). (4) The branching output terminals of the optical multiplexing/branching device according to claim (1) for different optical signals of n wavelengths are connected to an optical repeater having n input/output systems, and from the optical repeater, A claim characterized in that an optical signal having the same wavelength as the input is output (
3) The optical communication system described.