JPH04331514A - Optical repeater - Google Patents

Abstract

PURPOSE:To transmit inside monitor information to a terminal station with comparatively simple configuration not to require any high-speed circuit. CONSTITUTION:One output of an optical demultiplexer 1 is connected through an optical filter 2 to the input of an optical amplifier 6. The other output of the optical demultiplexer 1 is connected through an optical filter 3 to the input of a photoelectric converter 4. The output of the photoelectric converter 4 is connected to the input of a monitor and control circuit 5. The output of the optical amplifier 6 is connected to the input of an optical demultiplexer 7, one output is connected through an optical filter 9 to one input of an optical demultiplexer 10, and the other output is connected through an optical filter 8 to an optical switch 11. The output of this optical switch 11 is connected to the other input of the optical demultiplexer 10, and a response signal output terminal 12 of the monitor and control circuit 5 is connected to a switch on/off control terminal 13 of the optical switch 11. By splitting and modulating excited light, the inside monitor information can be transmitted to the terminal station without using any high-speed circuit.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to an optical repeater, and more particularly to an optical repeater that has a supervisory control function and performs optical direct amplification using a pumping laser having a wavelength different from the main signal optical wavelength. .

0002

[Prior Art] Conventionally, in an optical repeater having a supervisory control function, in order to send out various monitor information in the repeater to a terminal station, a method of applying mark rate modulation or phase modulation to the main symbol has been used. was taken.

0003

[Problem to be solved by the invention] With this conventional means,
Since the main signal must be first converted into an electrical signal, modulated, and then converted back into an optical signal, a high-speed circuit for modulation was required. Particularly in the ultra-high-speed region of 1 Gb/s or higher, it is technically difficult to realize such a modulation circuit. In particular, direct optical amplifiers have the advantage of being simple in configuration because they transmit optical signals as they are without the need for high-speed electrical circuits, and the problem is that the conventional technology described above cannot take advantage of this advantage. was there.

0004

[Means for Solving the Problems] The optical repeater of the present invention has a supervisory control function and performs optical direct amplification using a pumping laser having a wavelength different from the main signal light wavelength. A first output of the optical demultiplexer is connected to the input of the optical amplifier via a first optical filter, and a second output of the first optical demultiplexer is connected to the optical/electrical input via a second optical filter. the output of the optical/electrical converter is connected to the input of a supervisory control circuit; the output of the optical amplifier is connected to the input of a second optical demultiplexer; The first output of the demultiplexer is connected to the first input of the optical multiplexer via a third optical filter, and the second output of the second optical demultiplexer is connected to the optical switch via a fourth optical filter. The output of this optical switch is connected to the second input of the optical multiplexer, and the response signal output terminal of the monitoring control circuit is connected to the switch opening/closing terminal of the optical switch.

Further, in the optical repeater according to another aspect of the present invention, the first output of the optical demultiplexer is connected to the input of the optical amplifier via the first optical filter, and the second output of the optical demultiplexer is connected to the input of the optical amplifier via the first optical filter. output is second
The output of the optical/electrical converter is connected to the input of a monitoring control circuit, and the output of the optical amplifier is optically multiplexed through a third filter. The output of the laser diode is connected to the second input of the optical multiplexer, and the response signal output terminal of the monitoring control circuit is connected to the input of the laser diode drive circuit. be.

[0006]

[Operation] In the present invention, excitation light is separated and modulated.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, 1 is an optical demultiplexer, one output of the optical demultiplexer 1 is connected to the input of an optical amplifier 6 via an optical filter 2, and the other output of the optical demultiplexer 1 is an optical demultiplexer. The output of the optical/electrical converter 4 is connected to the input of the monitoring control circuit 5, and the output of the optical amplifier 6 is connected to the input of the optical demultiplexer 7. connected to,
One output of this optical demultiplexer 7 is connected to one input of an optical multiplexer 10 via an optical filter 9, and the other output of the optical demultiplexer 7 is connected to an optical switch 11 via an optical filter 8. The output of this optical switch 11 is connected to the other input of the optical multiplexer 10, and the response signal output terminal 1 of the supervisory control circuit 5.
2 is connected to the switch opening/closing terminal 13 of the optical switch 11. Further, λ1 is a main signal and indicates signal light, and λ2 is a response signal and indicates excitation light.

FIG. 2 is a block diagram showing an example of the configuration of the optical amplifier in FIG. 1. In FIG. 2, reference numeral 14 denotes an optical multiplexer, and the optical multiplexer 14 multiplexes the signal light λ1 and the pumping light λ2 emitted from the pumping laser 15, and inputs the signal light λ1 into the Er-doped fiber 16. An optical isolator 17 is arranged at the output of this Er-doped fiber 16.

Next, the operation of the embodiment shown in FIG. 1 will be explained. First, consider how this optical repeater monitors internal information, such as input signal level and output signal level, and sends it to a terminal station. The monitoring control circuit 5 A/D converts the information into 1/0 digital information, and serially outputs the 1/0 digital information to the response signal output terminal 12. On the other hand, the optical amplifier 6 outputs the signal light λ1 and the pump light λ2, which are split into two by the optical demultiplexer 7. Then, they are passed through an optical filter 8 and an optical filter 9 to perform wavelength selection and separate the signal light λ1 and the excitation light λ2. The separated excitation light λ2 is input to the optical switch 11. This optical switch 11 opens and closes depending on the voltage level of the switch opening/closing control terminal 13. Here, the optical switch 11 is opened and closed by internal information output by connecting the response signal output terminal 12 and the switch opening/closing control terminal 13.
Pumping light λ2 according to 1/0 digital information of internal information
can be ON/OFF modulated. Then, the modulated pumping light λ2 is sent to the optical multiplexer 10 again.
It is combined with the main signal λ1 and sent out.

[0010] Next, the operation of the next-stage repeater when multiple relays are performed will be explained. The main signal λ1 sent from the previous repeater and the response signal λ2 modulated by the monitor information are split by the optical demultiplexer 1, and then separated into the main signal λ1 and the response signal λ2 by the optical filters 2 and 3. The main signal λ1 is input to the optical amplifier 6, while the response signal λ2 is converted into an electrical signal by the optical/electrical converter 4 and input to the supervisory control circuit 5. This monitoring control circuit 5
Then, the response signal λ2 is recognized, the same signal is outputted from the response signal output terminal 12, and the response signal λ2 is modulated as described above and transmitted together with the main signal λ1. By repeating the above operations, information can be transferred to the terminal station.

FIG. 3 is a block diagram showing another embodiment of the present invention. In FIG. 3, the same reference numerals as in FIG. 1 indicate corresponding parts; 18 is an optical multiplexer, 19 is a laser diode, and 20 is a laser diode drive circuit. The output of the optical amplifier 6 is then passed through an optical filter 9 to an optical multiplexer 1.
The output of the laser diode 19 is connected to the other input of the optical multiplexer 18, and the response signal output terminal 12 of the supervisory control circuit 5 is connected to the input of the laser diode drive circuit 20. .

[0012] In the optical repeater configured in this way,
Information from the supervisory control circuit 5 is output from the response signal output terminal 12, and the signal is input to the laser diode drive circuit 20, thereby causing the laser diode 19 to emit light with excitation light λ2 according to the information. Then, the optical multiplexer 18 multiplexes the optical signal with the main signal λ1 and sends it out.

[0013]

As explained above, the present invention separates and modulates pump light in an optical repeater that performs direct optical amplification using a pump laser with a wavelength different from the main signal light wavelength. This has the advantage that internal monitor information can be sent to a terminal station with a relatively simple configuration that does not require a high-speed circuit.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration example of the optical amplifier in FIG. 1;

FIG. 3 is a block diagram showing another embodiment of the present invention.

[Explanation of symbols]

1 Optical demultiplexer 2, 3 Optical filter 4. Optical/electrical converter 5 Monitoring control circuit 6. Optical amplifier 7 Optical demultiplexer 8,9 Optical filter 10 Optical multiplexer 11 Optical switch 12 Response signal output terminal 13　Switch opening/closing control terminal 18 Optical multiplexer 19 Laser diode 20 Laser diode drive circuit

Claims (2)

[Claims] Claim 1: In an optical repeater having a monitoring control function and performing direct optical amplification using a pumping laser having a wavelength different from the main signal optical wavelength, the first output of the first optical demultiplexer is The second output of the first optical demultiplexer is connected to the input of an optical/electrical converter via a second optical filter, and the optical/electrical The output of the converter is connected to the input of a supervisory control circuit, the output of the optical amplifier is connected to the input of a second optical demultiplexer, and the first output of the second optical demultiplexer is connected to the input of a third optical demultiplexer. The second output of the second optical demultiplexer is connected to an optical switch via a fourth optical filter, and the output of this optical switch is connected to the first input of the optical multiplexer through a filter. An optical repeater characterized in that the optical repeater is connected to a second input of the optical switch, and a response signal output terminal of the monitoring control circuit is connected to a switch opening/closing terminal of the optical switch. 2. In an optical repeater having a monitoring control function and performing direct optical amplification using a pumping laser having a wavelength different from the main signal optical wavelength, the first output of the optical demultiplexer is connected to the first optical filter. a second output of said optical demultiplexer is connected to an input of an optical/electrical converter via a second optical filter, and the output of said optical/electrical converter is monitored. connected to the input of the control circuit, the output of the optical amplifier is connected to the first input of the optical multiplexer via a third optical filter, and the output of the laser diode is connected to the second input of the optical multiplexer, An optical repeater characterized in that a response signal output terminal of the monitoring control circuit is connected to an input of the laser diode drive circuit.