JP2007158523A - Optical amplifier and optical transmission system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical amplifier capable of coping with whole failures in an optical transmission system and to provide the optical transmission system. <P>SOLUTION: The optical transmission system 10 includes: an input section 14 for receiving an optical signal; an output section 16 for outputting the optical signal; and the optical amplifier 12 provided between the input section 14 and the output section 16. An optical demultiplexer section 122 of the optical amplifier 12 demultiplexes the optical signal received by the input section 14 into N optical signals and transmits the optical signals through N optical fibers 123. Optical amplifier sections 124 respectively amplify the N optical signals demultiplexed by the optical demultiplexer section 122 and transmit the amplified optical signals to an optical multiplexer 126 through the optical fibers 123. The optical multiplexer 126 multiplexes the N optical signals amplified by the optical amplifier sections 124, uniformly distributes the multiplexed signal into N optical signals and transmits them through N optical fibers 125, and the optical signals are outputted from output sections 16. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical amplification device and an optical transmission system.

  In the conventional optical transmission system, in order to improve the reliability of the system, it is important to construct system redundancy. For example, there is an optical transmission system in which a backup path (line) is provided. However, in order to provide a backup path for all paths, a large amount of capital investment is required, leading to an increase in cost.

Therefore, a system that improves the reliability of the system by configuring redundancy of the excitation light source by using more excitation light sources than the minimum necessary number is cited. For example, in the optical amplifier described in Patent Document 1, the pumping power from each of the two laser diodes is set to 2 by the coupler means disposed between the two directional couplers and the two laser diodes. Coupling to one optical fiber improves system reliability by simultaneously operating with reduced power until one laser diode fails and the other laser diode operates with increased power.
Japanese Patent No. 2922732

  However, the optical transmission system described above copes with a failure of a laser diode as a pumping light source, and cannot cope with a failure other than the pumping light source such as a control circuit failure or a failure of an optical component. It was.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an optical amplifying apparatus and an optical transmission system that can cope with a failure of the entire optical transmission system.

  An optical amplifying device according to the present invention is an optical amplifying device used in an optical transmission system that transmits an optical signal, and is branched by an optical branching unit that branches an optical signal into N optical signals, and an optical branching unit An optical amplifying unit that amplifies each of the N optical signals, and an optical coupler that collects the N optical signals amplified by the optical amplifying unit and distributes them to the N optical signals. However, N is an integer of 2 or more.

  In the optical amplifying device according to the present invention, the optical signal is branched into N optical signals by the optical branching unit, amplified by the optical amplifying unit, and then collected by the optical coupler, and further distributed to the N optical signals. And output. For this reason, each optical signal is averaged and output. Therefore, when a failure occurs in the optical transmission system and the level of the optical signal is reduced, each optical signal is averaged by the optical coupler, thereby preventing the output optical signal from being interrupted. Therefore, it is possible to deal with failures in the entire optical transmission system.

  An optical amplifying device according to the present invention is an optical amplifying device used in an optical transmission system that transmits an optical signal, and an optical amplifying unit that amplifies the optical signal, and N optical signals amplified by the optical amplifying unit. An optical branching unit that branches to an optical signal and an optical coupler that collects N optical signals branched by the optical branching unit and distributes them to the N optical signals are provided. However, N is an integer of 2 or more.

  In the optical amplifying device according to the present invention, the optical signal is amplified by the optical amplifying unit, branched to N optical signals by the optical branching unit, then collected by the optical coupler, and further distributed to the N optical signals. Is output. For this reason, each optical signal is averaged and output. Therefore, when a failure occurs in the optical transmission system and the level of the optical signal is reduced, each optical signal is averaged by the optical coupler, thereby preventing the output optical signal from being interrupted. Therefore, it is possible to deal with failures in the entire optical transmission system.

  In the optical amplifying device according to the present invention, it is preferable that the optical amplifying device further includes a compensation unit that compensates for a phase delay between the N optical signals distributed and output by the optical coupler. In this case, it is possible to compensate for the phase shift of the optical signal caused by the difference in the optical path length of the transmission path when combining the output of the optical signal after branching, and to obtain a stable optical signal output.

  In the optical amplifying device according to the present invention, the value of N is preferably 2. In this case, an inexpensive redundant configuration can be realized.

  An optical transmission system according to the present invention includes the above-described optical amplification device according to the present invention. In this case, by using an optical amplifying device comprising an optical branching unit, an optical amplifying unit, and an optical coupler, a transmission system that can cope with the failure of the entire optical transmission system and can prevent the output optical signal from being interrupted. Is obtained.

  An optical transmission system according to the present invention is an optical transmission system that splits an optical signal into N optical signals and transmits the optical signals. The N first optical fibers that transmit the branched N optical signals respectively, The first optical fiber is provided between the first optical fiber, the second optical fiber provided one-to-one, and the N first optical fibers and the N second optical fibers, and transmitted by the N first optical fibers. And an optical coupler for collecting, distributing, and transmitting the N optical signals to the N second optical fibers. However, N is an integer of 2 or more.

  In the optical transmission system according to the present invention, by providing an optical coupler between the first optical fiber and the second optical fiber, the optical signal transmitted from the first optical fiber is averaged by the optical coupler. The light enters the second optical fiber and is output. Therefore, when a failure occurs in the optical transmission system and the level of the optical signal is reduced, each optical signal is averaged by the optical coupler, thereby preventing the output optical signal from being interrupted. Therefore, it is possible to deal with failures in the entire optical transmission system.

  ADVANTAGE OF THE INVENTION According to this invention, the optical amplifier which can respond to the failure of the whole optical transmission system and an optical transmission system can be provided.

  The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant descriptions are omitted.

[First embodiment]
First, a first embodiment of an optical transmission system according to the present invention will be described. FIG. 1 is a configuration diagram of an optical transmission system 10 according to the first embodiment. An optical transmission system 10 according to the present embodiment is a system that transmits an optical signal, and includes one input unit 14 that inputs an optical signal, N output units 16 that output an optical signal, an input unit 14, and an output. And an optical amplifying device 12 provided between the units 16. In the present embodiment, N is an integer of 2 or more.

  The optical amplifying device 12 includes an optical branching unit 122, an optical amplifying unit 124, an optical coupler 126, and optical fibers 121, which are arranged in order from the input unit 14 toward the output unit 16, and between these optical components. 123, 125.

  The optical branching unit 122 is optically connected to the input unit 14 through one optical fiber 121, and the optical signal input to the input unit 14 and transmitted by the optical fiber 121 is converted into N optical signals. Branch and transmit to N optical fibers 123.

  The optical amplifying units 124 are provided one-to-one with respect to the N optical fibers 123 in the middle of the N optical fibers 123 that optically connect the optical branching unit 122 and the optical coupler 126. The optical amplifying unit 124 amplifies the N optical signals branched by the optical branching unit 122 and transmitted by the optical fiber 123, and further causes the optical fiber 123 to transmit to the optical coupler 126 side.

  The optical coupler 126 collects N optical signals amplified by the optical amplifying unit 124 and transmitted through the optical fiber 123, and further equally distributes the N optical signals. N optical fibers 125 are provided between the optical coupler 126 and the output unit 16. The optical fiber 125 transmits N optical signals equally distributed by the optical coupler 126 to the N output units 16, respectively. The optical fibers 121, 123, and 125 may be the same type of fiber, or different types of optical fibers may be used as necessary.

  The optical transmission system 10 operates as follows. In other words, the optical signal input to the input unit 14 is transmitted to the optical branching unit 122 through the optical fiber 121, where it is branched into N optical signals. The branched N optical signals are incident on the corresponding N optical fibers 123, amplified by the optical amplifying unit 124 provided in the middle of the optical fiber 123, and transmitted to the optical coupler 126. The N optical signals transmitted to the optical coupler 126 are collected by the optical coupler 126, further distributed equally to the N optical signals, and transmitted to the output unit 16 through the corresponding N optical fibers 125. And output from the output unit 16.

  According to the optical transmission system 10 of this embodiment, the optical signal is branched into N optical signals by the optical branching unit 122, amplified by the optical amplifying unit 124, and further combined by the optical coupler 126. Since the signals are equally distributed and output, each optical signal is averaged and output. Therefore, when a failure occurs in the optical transmission system 10 and the level of the optical signal decreases, each optical signal is averaged by the optical coupler 126 to prevent the output optical signal from being interrupted. Therefore, it is possible to cope with the failure of the optical transmission system 10 in general.

[Second Embodiment]
Next, a second embodiment of the optical transmission system according to the present invention will be described. FIG. 2 is a configuration diagram of the optical transmission system 20 according to the second embodiment. The optical transmission system 20 according to the present embodiment is a system that transmits an optical signal, and includes one input unit 24 that inputs an optical signal, N output units 26 that output an optical signal, an input unit 24, and an output. And an optical amplifying device 22 provided between the units 26. In the present embodiment, N is an integer of 2 or more.

  The optical amplifying device 22 is arranged in order from the input unit 24 toward the output unit 26, and includes an optical amplifying unit 224, an optical branching unit 222, an optical coupler 226, and an optical fiber 221 arranged between these optical components. , 223, 225.

  The optical amplifying unit 224 is provided in the middle of one optical fiber 221 that optically connects the input unit 24 and the optical branching unit 222. The optical amplifying unit 224 amplifies the optical signal input to the input unit 24 and transmitted by the optical fiber 221, and further transmits the amplified optical signal to the optical fiber 221 toward the optical branching unit 222.

  The optical branching unit 222 is provided between the optical amplification unit 224 and the optical coupler 226, and is optically connected to the optical amplification unit 224 and the optical coupler 226 via the optical fiber 221 and the optical fiber 223, respectively. Yes. The optical branching unit 222 branches N optical signals from the optical signal amplified by the optical amplifying unit 224 and transmitted by the optical fiber 221, and optically couples the branched N optical signals to the N optical fibers 223. The data is transmitted to the device 226.

  The optical coupler 226 is optically connected to the optical branching unit 222 via N optical fibers 223. The optical coupler 226 compiles N optical signals branched by the optical branching unit 222 and transmitted by the optical fiber 223, and further equally distributes the N optical signals to the equally distributed N optical signals. The signals are transmitted to N optical fibers 225 and output from the output unit 26. In addition, the same kind of fiber may be used for the optical fibers 221, 223, and 225, and different kinds of optical fibers may be used as necessary.

  The optical transmission system 20 operates as follows. That is, the optical signal input to the input unit 24 is transmitted through the optical fiber 221 and reaches the optical amplifying unit 224, where it is amplified, further transmitted to the optical branching unit 222 through the optical fiber 221, and N by the optical branching unit 222. It is branched into optical signals. The branched N optical signals are incident on the corresponding optical fibers 223 and transmitted to the optical coupler 226 through the optical fibers 223. The N optical signals transmitted to the optical coupler 226 are collected by the optical coupler 226, further distributed equally to the N optical signals, and transmitted to the output unit 26 through the corresponding optical fibers 225, respectively. Is output from the unit 26.

  According to the optical transmission system 20 according to the present embodiment, the optical signal is amplified by the optical amplifying unit 224, branched into N optical signals by the optical branching unit 222, and further combined by the optical coupler 226. Therefore, each optical signal is averaged and output. Therefore, when a failure occurs in the optical transmission system 20 and the level of the optical signal decreases, each optical signal is averaged by the optical coupler 226, thereby preventing the output optical signal from being interrupted. Therefore, it is possible to cope with a failure of the optical transmission system 20 in general.

[Third embodiment]
Next, a third embodiment of the optical transmission system according to the present invention will be described. FIG. 3 is a configuration diagram of an optical transmission system 30 according to the third embodiment. The optical transmission system 30 according to the present embodiment is a system that transmits an optical signal, and includes an input unit 34 that inputs an optical signal, two output units 36 that output an optical signal, an input unit 34, and an output. And an optical amplifying device 32 provided between the units 36.

  The optical amplifying device 32 includes an optical amplifying unit 324, an optical branching unit 322, an optical amplifying unit 328, an optical coupler 326, an optical amplifying unit 329, and these lights arranged in order from the input unit 34 to the output unit 36. It is composed of optical fibers 321, 323, 325, and 327 arranged between components.

  The optical amplifying unit 324 is provided in the middle of one optical fiber 321 that optically connects the input unit 34 and the optical branching unit 322. The optical amplifying unit 324 amplifies the optical signal input to the input unit 34 and transmitted by the optical fiber 321, and further transmits the amplified optical signal to the optical fiber 321 toward the optical branching unit 322.

  The optical branching unit 322 is provided between the optical amplifying unit 324 and the optical amplifying unit 328, and branches the optical signal amplified by the optical amplifying unit 324 and transmitted through the optical fiber 321 into two optical signals. The two branched optical signals are transmitted to the two optical fibers 323, respectively.

  The optical amplifying unit 328 is provided in one-to-one relationship with the two optical fibers 323 in the middle of the two optical fibers 323 that optically connect the optical branching unit 322 and the optical coupler 326. The optical amplifying unit 328 amplifies two optical signals branched by the optical branching unit 322 and transmitted by the optical fiber 323, and further transmits the optical signal to the optical coupler 326.

  The optical coupler 326 is disposed between the optical amplifying unit 328 and the optical amplifying unit 329, collects two optical signals amplified by the optical amplifier 328 and transmitted through the optical fiber 323, and further adds two optical signals. And the two equally distributed optical signals are transmitted to the optical fiber 325 and the optical fiber 327, respectively.

  The optical amplifiers 329 are provided one-to-one with respect to the optical fibers 325 and 327 in the middle of the optical fibers 325 and 327. This optical amplifying unit 329 further amplifies the two optical signals equally distributed by the optical coupler 326, transmits them to the output unit 36 through the optical fibers 325 and 327, and outputs them from the output unit 36.

  In the present embodiment, a single delay fiber 327 is provided as a compensation means in order to compensate for the phase shift of the optical signal caused by the difference in the optical path length of the transmission path when the optical signal output after branching is combined. ing. In this case, it is possible to compensate for the phase lag between the two optical signals equally distributed and output by the optical coupler 326, and to obtain a stable optical signal output. The optical fibers 321, 323, and 325 may be the same type of fiber, or different types of optical fibers may be used as necessary.

  The optical transmission system 30 operates as follows. That is, the optical signal input to the input unit 34 is transmitted through the optical fiber 321 and reaches the optical amplifying unit 324, where it is amplified, further transmitted to the optical branching unit 322 through the optical fiber 321, and 2 by the optical branching unit 322. It is branched into optical signals. The two branched optical signals are incident on the corresponding two optical fibers 323, further amplified by the optical amplification unit 328, and transmitted to the optical coupler 326 through the optical fiber 323. The two optical signals transmitted to the optical coupler 326 are collected by the optical coupler 326, are equally distributed to the two optical signals, and are transmitted by the corresponding optical fibers 325 and 327, respectively. The two optical signals are further amplified by an optical amplifying unit 329 provided in the middle of the optical fiber 325 and the optical fiber 327 and output from the output unit 36.

  According to the optical transmission system 30 of the present embodiment, the optical signal is amplified by the optical amplifying unit 324, branched into two optical signals by the optical branching unit 322, and then amplified by the optical amplifying unit 328, and the optical coupler. Since the signals are combined by 226, equally distributed to two optical signals and output, and further amplified by the optical amplifying unit 329, each optical signal is averaged and output. Therefore, for example, even when one of the two optical signals is significantly reduced due to a failure, the output optical signal is interrupted by suppressing the decrease of each optical signal to a level of about 3 dB. It is possible to prevent a failure of the optical transmission system 30 in general.

  Further, in this embodiment, since the delay fiber 327 is provided, it is possible to compensate for the phase shift of the optical signal caused by the difference in the optical path length of the transmission path when the optical signal output after the branching is combined, and stable. An optical signal output can be obtained.

[Fourth embodiment]
Next, a fourth embodiment of the optical transmission system according to the present invention will be described. FIG. 4 is a configuration diagram of an optical transmission system 40 according to the fourth embodiment. The optical transmission system 40 according to the present embodiment is an optical transmission system that branches and transmits one input optical signal into N optical signals, and includes an input unit 44, an optical branching unit 42, and an optical amplification unit 47. 49, an optical coupler 48, an output unit 46, an optical fiber 41, a first optical fiber 43, and a second optical fiber 45. The optical fiber 41 is an optical fiber that transmits the optical signal input to the input unit 44 toward the optical branching unit 42, and the first optical fiber 43 optically couples the N optical signals branched by the optical branching unit 42. The second optical fiber 45 is provided in a one-to-one relationship with the N first optical fibers 43 and outputs N optical signals evenly distributed by the optical coupler 48 to the output unit. 46 is an optical fiber that transmits toward 46. In the present embodiment, N is an integer of 2 or more.

  The optical branching unit 42 is optically connected to the input unit 24 via one optical fiber 41, branches an optical signal transmitted through the optical fiber 41 into N optical signals, The first optical fiber 43 is transmitted.

  The optical amplifying unit 47 is provided in a one-to-one relationship with the N first optical fibers 43 in the middle of the N first optical fibers 43 that optically connect the optical branching unit 42 and the optical coupler 48. It has been. The optical amplifying unit 47 amplifies the N optical signals branched by the optical branching unit 42 and transmitted by the first optical fiber 43, and further causes the first optical fiber 43 to transmit to the optical coupler 48 side.

  The optical coupler 48 is disposed between the first optical fiber 43 and the second optical fiber 45, and collects N optical signals amplified by the optical amplification unit 47 and transmitted by the first optical fiber 43. Further, the optical signals are equally distributed to N optical signals, and the N optical signals that are equally distributed are respectively incident on the N second optical fibers 45.

  The optical amplifiers 49 are provided one-to-one with respect to the second optical fiber 45 in the middle of the second optical fiber 45. The optical amplifying unit 49 further amplifies the N optical signals equally distributed by the optical coupler 48, transmits it to the second optical fiber 45 toward the output unit 46, and outputs it from the output unit 46. The optical fiber 41, the first optical fiber 43, and the second optical fiber 45 may use the same type of fiber, or may use different types of optical fibers as necessary.

  The optical transmission system 40 operates as follows. In other words, the optical signal input to the input unit 44 is transmitted to the optical branching unit 42 through the optical fiber 41, where it is branched into N optical signals. The branched N optical signals are incident on the corresponding N first optical fibers 43, amplified by an optical amplifying unit 47 provided in the middle of the first optical fibers 43, and up to the optical coupler 48. Is transmitted. The N optical signals transmitted to the optical coupler 48 are collected by the optical coupler 48 and further equally distributed to the N optical signals. The output units 46 are respectively provided by the corresponding N second optical fibers 45. And output from the output unit 46.

  According to the optical transmission system 40 of this embodiment, the optical coupler 48 is provided between the first optical fiber 43 and the second optical fiber 45, so that the optical fiber is branched by the branching unit 42 and transmitted by the first optical fiber 43. The N optical signals thus obtained are averaged by the optical coupler 48 and incident on the second optical fiber 45 and output. Therefore, when a failure occurs in the optical transmission system 40 and the level of the optical signal decreases, each optical signal is averaged by the optical coupler 48 to prevent the output optical signal from being interrupted. It is possible to cope with the failure of the entire optical transmission system.

  The present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

1 is a configuration diagram of an optical transmission system according to a first embodiment. FIG. It is a block diagram of the optical transmission system which concerns on 2nd Embodiment. It is a block diagram of the optical transmission system which concerns on 3rd Embodiment. It is a block diagram of the optical transmission system which concerns on 4th Embodiment.

Explanation of symbols

  10, 20, 30, 40 ... optical transmission system, 12, 22, 32 ... optical amplification device, 42, 122, 222, 322 ... optical branching unit, 47, 49, 124, 224, 324, 328 ... optical amplification unit, 48, 126, 226, 326 ... optical couplers, 43 ... first optical fiber, 45 ... second optical fiber, 327 ... delay fiber.

Claims (6)

An optical amplifier used in an optical transmission system for transmitting an optical signal,
An optical branching unit for branching the optical signal into N optical signals;
An optical amplifying unit for amplifying the N optical signals branched by the optical branching unit;
An optical coupler that collects the N optical signals amplified by the optical amplifier and distributes the N optical signals to the N optical signals;
An optical amplifying device (where N is an integer of 2 or more). An optical amplifier used in an optical transmission system for transmitting an optical signal,
An optical amplifier for amplifying the optical signal;
An optical branching unit that branches the optical signal amplified by the optical amplification unit into N optical signals;
An optical coupler that collects the N optical signals branched by the optical branching unit and distributes the N optical signals to the N optical signals;
An optical amplifying device (where N is an integer of 2 or more).   3. The optical amplifying apparatus according to claim 1, further comprising compensation means for compensating for a phase delay between the N optical signals distributed and output by the optical coupler.   4. The optical amplifying apparatus according to claim 1, wherein the value of N is two.   An optical transmission system comprising the optical amplifying device according to claim 1. In an optical transmission system that splits an optical signal into N optical signals and transmits them,
N first optical fibers that respectively transmit the branched N optical signals;
A second optical fiber provided one-on-one with the N first optical fibers;
The N optical signals are provided between the N first optical fibers and the N second optical fibers, and the N optical signals transmitted through the N first optical fibers are collected, distributed, and distributed. An optical coupler to be transmitted to the second optical fiber;
An optical transmission system (where N is an integer of 2 or more).

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