JPH03187536A - Optical repeater - Google Patents

Abstract

PURPOSE:To easily execute the standardization of a fault point with simple constitution by providing an oscillator, which is equipped with an intrinsic transmission frequency, and a laser diode light source to be driven by the oscillator in each optical repeater. CONSTITUTION:An optical amplifier 20, optical multiplexer 21 and a laser diode 22, which is provided as the light source to generate an input to the optical multiplexer 21 together with the output of the optical amplifier 20, are provided. Then, an oscillator 23 is provided to oscillate various frequencies for each optical repeater, and a supervisory and control circuit 24 is provided to output a control signal for turning ON/OFF the operation of the oscillator 23 by a command to be presented from a terminal through the optical amplifier 20. Thus, since providing the oscillator 23 to output the oscillation frequency intrinsic for the repeater and the light source to be modulated by the output of the oscillator 23, the fault point can be standardized by the simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical repeater, and particularly to an optical repeater using an optical amplifier.

[Conventional technology]

In optical relay transmission, fault point location for line faults is one of the important techniques. Especially in the field of submarine relay,
It is very important to be able to search for fault points in the undersea section at the landing station.

Conventionally, as this type of technology, a signal looping method in an optical repeater has been adopted.

FIG. 3 is a configuration diagram showing a typical example of operation of a conventional optical repeater. Conventionally, a plurality of optical repeaters of this type have been installed on each of the signal outgoing and return paths between terminal stations 1 and 2 that face each other via a transmission line and perform bidirectional communication, and are used to locate fault points on the transmission line. For the purpose of forming a circuit for this purpose, switches 9, 10, 11, 12, 13, 14, etc. were provided between the forward and return optical repeaters.

Now, in FIG. 3, it is assumed that ■ is a failure point.

Terminal station 1 sends a signal return control signal (hereinafter referred to as LB command) to each repeater in turn.0 For example, when an LB command is sent to optical repeater 3, switch 10 closes, and therefore terminal station 1 The sent signal returns to the terminal station 1 via the optical repeater 3 → switch 10 → optical repeater 6.

Similarly, when the switch 12 is closed, the signal sent from the terminal station 1 returns to the terminal station 1 via the optical repeater 3 → optical repeater 4 → switch 12 → optical repeater 7 → optical repeater 6. . However, even if the switch 14 is closed and the signal is sent from the terminal station, a failure occurs between the optical repeater 7 and the optical repeater 8, so the signal does not return to the terminal station 1. In this way, the optical repeater 7
This indicates that there is a problem in the section marked 8 and 8.

Each optical repeater that realizes the above signal looping method has a fourth
As shown in the figure, a switch 17, a supervisory control circuit 16 that receives commands and controls the switch 17, and an optical multiplexer 18
and the optical demultiplexer 19 on the outward path.

A pair is provided for the return trip.

On the other hand, in recent years, optical amplifier systems that directly amplify optical signals have been developed.
Conventional 3R (Reshaping, Regener)
ating.

It has been developed as an alternative to optical repeaters with a (Retiming) function, and there is a need for a failure point search method that is compatible with its simple circuit configuration.

[Problem to be solved by the invention]

In the conventional optical repeater with the signal looping function mentioned above,
In order to perform signal loopback one by one for each repeater,
Each repeater needs to have a unique address, and in FIG. 3 mentioned above, for example, switch 9 and switch
If both are turned on at the same time, a signal loop will occur, and a circuit to avoid this is required, resulting in a disadvantage that the circuit configuration of the supervisory control circuit 16 becomes complicated.

[Means to solve the problem]

The optical repeater of the present invention is an optical repeater equipped with an optical amplifier that directly amplifies an input optical signal, and includes an oscillator that outputs an oscillation frequency unique to the repeater, and a light source that is modulated by the output of the oscillator. an optical sonicator that combines and outputs the output of the optical amplifier and the output of the light source; and a monitoring control circuit that controls the operation of the oscillator.

Moreover, the optical repeater of the present invention has a configuration in which the light source is a laser diode.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of an optical repeater according to the present invention, and FIG. 2 is a block diagram showing an example of operation of the optical repeater according to the embodiment of FIG.

The optical repeater according to the embodiment shown in FIG. Oscillator 2 that oscillates a different frequency for each
3, and a monitoring control circuit 24 that outputs a control signal for turning on and off the operation of the oscillator 23 in response to commands provided from the terminal station via the optical amplifier 20.

Next, the operation of the optical repeater of the embodiment shown in FIG. 1 will be explained.

The output of the optical amplifier 20 is input as the first input of the optical multiplexer 21 with two inputs and one output, and the output of the laser diode 22 is supplied to the second input.

The laser diode 22 is driven by an oscillator 23, and the on/off operation of the 0 oscillator 23 is controlled by a control signal output from a supervisory control circuit 24. When the supervisory control circuit 24 outputs a control signal to turn on the oscillator, the oscillator 23
oscillates at a unique oscillation frequency f1 assigned to each repeater. Laser diode No. 22 is modulated with this oscillation frequency and sent to the terminal station of the other party via optical multiplexer 21.

Figure 2 shows an example of the operation of the optical repeater according to the embodiment shown in Figure 1, and shows an example of a system in which two optical repeaters according to the embodiment shown in Figure 1 are repeated.The oscillation frequency of the oscillator of each repeater is fl * f2
+ It is different from fl. Assuming that the point (■) is a failure point, a command to turn on the oscillator 23 is sent from the terminal station to each supervisory control circuit 24, causing each oscillator to oscillate. On the B side of the terminal station, optical signals modulated by fs, fz, fl are observed, but on the A side of the terminal station, fr, f2L are observed.
is not observed. Thus, the fault point ■ can be located.

〔Effect of the invention〕

As explained above, the present invention has the effect that fault points can be easily located by using a simple configuration in which each optical repeater is equipped with an oscillator having a unique oscillation frequency and a laser diode light source driven by the oscillator. be.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an embodiment of the optical repeater of the present invention, Fig. 2 is a block diagram showing an operational example of the optical repeater of the embodiment of Fig. 1, and Fig. 3 is a block diagram of a conventional optical repeater. A block diagram showing an example of operation, FIG. 4 is a block diagram of a conventional optical repeater. 1.2...Terminal office, 3-8...Optical repeater, 9-14.
...Switch, 15... Optical repeater, 16... Supervisory control circuit, 17... Switch, 18... Optical multiplexer, 1
9... Optical demultiplexer, 20... Optical amplifier, 21... Optical multiplexer, 22... Laser diode, 3... Oscillator, 24... Monitoring control circuit.

Claims (1)

[Claims] 1. An optical repeater equipped with an optical amplifier that directly amplifies an input optical signal, an oscillator that outputs an oscillation frequency unique to the repeater, and a light source that is modulated by the output of the oscillator. an optical multiplexer that combines and outputs the output of the optical amplifier and the output of the light source; An optical repeater comprising: a monitoring control circuit that controls the operation of an oscillator. 2. The optical repeater according to claim 1, wherein the light source is a laser diode.