JPS63238728A - Optical transmitting equipment - Google Patents

Abstract

PURPOSE:To transmit double signals without using a light source, a photodetector, etc., for a long wavelength area by combining optical directional couplers for demultiplexing and multiplexing light having the same wavelength and an optical demultiplexer/multiplexer for demultiplexing/multiplexing light having different wavelengths in accordance with the wavelength. CONSTITUTION:When electric signals S1, S2 are inputted to an optical transmitting equipment 1, electrooptic converters 3A, 3B convert the input signals into optical signals with wavelengths lambda1, lambda2 and send the optical signals to the optical demultiplexer/multiplexer 5. The optical demultiplexer/multiplexer 5 multiplexes these optical signals and sends these signals to an optical transmitting equipment 1' through an optical fiber cable 2. The equipment 1' converts the optical signals with the wavelengths lambda1, lambda2 into electric signals S1', S2' in the reverse process against said process. When electric signals S3', S4' are inputted from the external to the equipment 1', the same processing as said one is executed and electric signals S3, S4 are obtained from an optical transmitting equipment 1. When 780/880mm is selected as the wavelengths lambda1, lambda2, parallel multiplex transmission for four signals with different wavelengths can be executed.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an optical transmission device.

[Prior Art] Conventionally, a time division method is known as a method of transmitting a plurality of optical signals through a single optical fiber. but,
In this time-division method, transmission efficiency deteriorates when high-speed transmission occurs. For this reason, recently, attempts have been made to use wavelength multiplexing for optical transmission.

This wavelength multiplexing method superimposes light of different wavelengths and transmits information to another optical transmission device through a single optical fiber, and has excellent transmission efficiency in high-speed transmission.

[Problems to be Solved by the Invention]However, in conventional wavelength multiplexing systems, when transmitting two or more signals, generally the 0.8 μm band and the 1.3 μm band are used.
It is necessary to use a combination of short wavelength and long wavelength light, such as a light source for long wavelengths.

The receiver is more expensive than one for short wavelength range.

There was a problem that it was not economical and it was begging.

Therefore, the present invention makes it possible to implement wavelength multiplexing without using expensive long wavelength light sources, photodetectors, etc. or with as few as possible, and to transmit twice as many signals as conventional wavelength multiplexing transmission. The purpose of the present invention is to provide an inexpensive and economical optical transmission device that can transmit data.

[Means for Solving the Problems] The present invention splits and combines two output lights of the same wavelength between a plurality of electrical/optical converters and a plurality of optical/electrical converters and one optical fiber cable. This is a combination of an optical directional coupler and an optical demultiplexer/multiplexer that splits and combines input and output lights of different wavelengths according to their wavelengths.

[Function] This makes it possible to easily branch or combine multiple different short wavelength lights without using expensive long wavelength light sources or receivers, and to transmit information using a single optical fiber cable using a wavelength multiplexing method. can be transmitted.

[Embodiment] FIG. 1 shows the configuration of an optical transmission device according to an embodiment of the present invention.

The optical transmission system consists of two optical transmission devices! 1.1' and one optical fiber cable 2 connecting these.

The optical transmission device 1 includes electrical-to-optical converters (indicated by Elo in the figure) 3A and 3B for inputting an external electrical signal S t I52 and converting it into an optical signal, and for converting the optical signal into an electrical signal. Optical/electrical converters (indicated by 0/E in the figure) 4A and 4B for converting into signals 53' and 54 combine the incident light, send it to the optical fiber cable 2, and transmit it to the optical fiber cable 2. The optical demultiplexer/multiplexer 5 branches and outputs the combined light, and the optical signal from the electrical/optical converter 3A is sent to the optical demultiplexer/multiplexer 5. Optical directional coupler 6A sending to optical/electrical converter 4A and electrical/optical converter 3
The optical directional coupler 6B sends the optical signal from the optical demultiplexer/multiplexer 5 to the optical demultiplexer/multiplexer 5, and sends the optical signal from the optical demultiplexer/multiplexer 5 to the optical/electrical converter 4B. Similarly, the optical transmission device 1' has an electric/optical converter 3A'.

3B', optical/electrical converters 4A', 4B', optical demultiplexer/multiplexer 5', and optical directional couplers 6A', 6B'.

With the above configuration, the electrical signal S1. When Ss is input to the optical transmission device 1, the electrical-to-optical converters 3A and 3B convert it into optical signals with wavelengths λl and λ2, respectively. Optical directional coupler 6
A and 6B input the converted wavelengths λl and λ2, respectively, and send them to the optical demultiplexer/multiplexer 5. The optical demultiplexer/multiplexer 5 combines these optical signals and sends them to the optical transmission device @1' via one optical fiber cable 2. The optical demultiplexer/multiplexer 5' in the optical transmission device 1' decomposes the sent composite wave into optical signals of wavelengths λL and λ2, and sends them to optical and electrical signals via optical directional couplers 6A' and 6B', respectively. It is sent to converters 4A' and 4B'. The optical/electrical converters 4A' and 4B' each receive the input wavelength λ! ,
The light of λ2 is converted into electrical signals Sl' and S2'.

At the same time, an electrical signal S3' is sent to the optical transmission device 1' from the outside.
When rS*' is input, the electrical/optical converter 3A'.

3B' is each wavelength λ! , converted into a λ2 optical signal.

This is sent to the optical demultiplexer/multiplexer 5' via the optical directional couplers 6^' and 6B'. The optical demultiplexer/multiplexer 5' combines these optical signals and sends them to the optical transmission device fl! via the optical fiber cable 2. ! Send to 1. Optical transmission bag r! The optical demultiplexer/multiplexer 5 in the optical demultiplexer/multiplexer 5 in the optical fiber optics 11 receives the combined wave at wavelength λ! , λ2, and sent to optical-to-electrical converters 4A, 4B via optical directional couplers 6A, 6B. Optical/electrical converter 4A, 4
B converts these optical signals into electrical signals Ss and S4 and sends them out.

In this way, bidirectional two-wavelength four-signal parallel multiplex transmission becomes possible. In this case, in particular, the wavelength λ1゜λ2 is 78
If 0/880nn is selected, parallel multiplex transmission of four wavelengths becomes possible using a light source and a light receiver for the short wavelength range.

As described above, according to this embodiment, parallel multiplex transmission using short wavelengths can be performed without using a light source and a light receiver for long wavelength ranges.

Note that, as shown in FIG. 2 or 3, the same effect as that of the above embodiment can be obtained even if the optical demultiplexer/multiplexers 5A, 5B and the optical directional coupler 6 are replaced.

In addition, in the above embodiment, the explanation was given using the case of 2 wavelengths 4 (No. or n optical directional couplers and one optical demultiplexer/multiplexer that split and combine input and output lights of n wavelengths into two-way parallel multiplex transmission of n wavelengths and 2n signals. It goes without saying that this is possible.

[Effects of the Invention] As explained above, according to the present invention, two-way parallel multiplex transmission of n wavelengths and 2n signals can be carried out with one optical fiber cable, and transmission speed is n times higher than that of n-channel time-division transmission. can be done. In addition, compared to conventional wavelength division multiplexing and multiplex transmission,
Since twice as many signals can be transmitted and there is no need to use a light source or photoreceiver for a long wavelength range, or the number thereof can be reduced, an economically superior optical transmission device can be obtained.

[Brief explanation of drawings]

FIG. 1 is a system configuration diagram of an optical transmission device according to one embodiment of the present invention, and FIGS. 2 and 3 are system configuration diagrams of optical transmission devices according to other embodiments of the invention. 1.1'... Optical transmission device, 2... Optical fiber cable, 3A, 3B, 3A', 3B'... Electrical/optical converter. 4A, 4B, 4A', 4B'...Optical/electrical converter, 5.5A, 5B, 5', 5A', 5B'
...Optical demultiplexer/multiplexer. 6.6A, 68.6', 6A', 6B'...
Optical directional coupler. ,＜:'：GPA agent Patent attorney Hiko Takeshihata...~Title・-I Shijie, I style

Claims (2)

[Claims] (1) In an optical transmission device that performs two-way parallel multiplex transmission of n-wavelength 2n signals by superimposing optical signals of n wavelengths and transmitting them through a single optical fiber, n electrical input signals are n electrical/optical converters that convert the n optical signals with different wavelengths into n optical signals with different wavelengths; and n electrical/optical converters that convert the n optical signals with different wavelengths into corresponding n electrical output signals. A converter branches and combines an optical signal input from one of the n electrical/optical converters and an optical signal output to one of the n electrical/optical converters at the same wavelength as this optical signal. n optical directional couplers, and the n optical signals of different wavelengths branched and combined by these n optical directional couplers are demultiplexed and multiplexed into an optical signal to be passed through the one optical fiber. An optical transmission device comprising one optical demultiplexer/multiplexer. (2) In an optical transmission device that performs two-way parallel multiplex transmission of n-wavelength 2n signals by superimposing optical signals of n wavelengths and transmitting them through a single optical fiber, n electrical input signals are n electrical/optical converters that convert the n optical signals with different wavelengths into n optical signals with different wavelengths; and n electrical/optical converters that convert the n optical signals with different wavelengths into corresponding n electrical output signals. converter, n optical signals with different wavelengths output from the n electrical/optical converters, and n optical signals with different wavelengths input to the n optical/electrical converters, Two optical demultiplexer/multiplexers each combine into one optical guide path by demultiplexing and multiplexing every n optical signals with different wavelengths regardless of their input/output directions; 1. An optical transmission device comprising: one optical directional coupler that combines optical guide paths of wave transmitters into one optical guide path and passes the optical fibers through the one optical fiber.