Optical communication system

Abstract

A light communication system is configured to have: a first optical fiber (3) that propagates communication light transmitted from a communication device (1) to a counterpart device (2); a second optical fiber (5) that propagates communication light transmitted from the counterpart device (2) to the communication device (1); a plurality of first bypass optical fibers (7-1 to 7-G) that bypass an optical amplifier (4) inserted to the first optical fiber (3); and a plurality of second bypass optical fibers (8-1 to 8-G) that bypass an optical amplifier (6) inserted to the second optical fiber (5). In addition, the light communication system has a sensor device (9) that sends sensor light to either of the first optical fiber (3) or the second optical fiber (5) and receives backscattered light returned from either of the first optical fiber (3) or the second optical fiber (5).

Description

Technical Field

[0001] This disclosure relates to optical communication systems. Background Technology

[0002] An optical communication system exists, comprising: an optical fiber for propagating communication light transmitted from a communication device to a peer device, and an optical fiber for propagating communication light transmitted from the peer device to the communication device. Optical amplifiers are typically inserted into each optical fiber, thus ensuring that the light propagation direction of each fiber is unidirectional.

[0003] As an example of such an optical communication system, Patent Document 1 discloses an optical communication system that, in addition to the optical fiber described above, also includes a sensing optical fiber for propagating sensor light and backscattered light between the communication device and the peer device. Since no optical amplifier is inserted into the sensing optical fiber, the light propagation direction of the sensing optical fiber is bidirectional. The optical communication system disclosed in Patent Document 1 includes a sensor device that sends sensor light into the sensing optical fiber and receives the backscattered light of the sensor light returning from the sensing optical fiber, and senses the communication optical fiber based on the backscattered light.

[0004] Patent Document 1: International Publication No. 2021-111699

[0005] In the optical communication system disclosed in Patent Document 1, in order for the sensor device to sense the optical fiber used for communication, it is necessary to lay a sensing optical fiber with the same length as the communication optical fiber. Therefore, this optical communication system has the following problem: the longer the distance between the communication device and the peer device, the longer the sensing optical fiber cable must be laid. Summary of the Invention

[0006] This disclosure was made to solve the aforementioned problems, with the aim of providing an optical communication system capable of sensing the optical fiber used for communication without laying an optical fiber for sensing that connects the communication device to the peer device.

[0007] The optical communication system disclosed herein includes: a first optical fiber that transmits communication light from a communication device to a peer device; a second optical fiber that transmits communication light from the peer device to the communication device; a plurality of first bypass optical fibers that bypass an optical amplifier inserted into the first optical fiber; and a plurality of second bypass optical fibers that bypass an optical amplifier inserted into the second optical fiber. Additionally, the optical communication system includes a sensor device that transmits sensor light to either the first or second optical fiber and receives backscattered light returned from either the first or second optical fiber.

[0008] According to this disclosure, it is possible to sense the optical fiber used for communication without laying the sensing optical fiber that connects the communication device and the peer device. Attached Figure Description

[0009] Figure 1 This is a structural diagram of the optical communication system in Implementation Method 1.

[0010] Figure 2 This is an explanatory diagram showing the spectral images of the sensor light and the backscattered light, respectively.

[0011] Figure 3 This is a structural diagram showing the optical communication system of Embodiment 2.

[0012] Figure 4 This is an explanatory diagram showing the wavelengths of communication light for N peer devices 2-1 to 2-N.

[0013] Figure 5 This is a structural diagram of the optical communication system in Embodiment 3.

[0014] Figure 6 This is a structural diagram of the optical communication system in Embodiment 4.

[0015] Figure 7 This is a structural diagram showing the optical communication system of Embodiment 5.

[0016] Figure 8 This is a structural diagram showing the optical communication system of Embodiment 6.

[0017] Figure 9 This is a structural diagram showing the optical communication system of embodiment 7.

[0018] Figure 10 This is a structural diagram showing a portion of the optical communication system in Embodiment 8.

[0019] Figure 11 This is a structural diagram showing a part of the optical communication system in Embodiment 9.

[0020] Figure 12 This is a structural diagram showing a portion of the optical communication system in Embodiment 10.

[0021] Figure 13 This is a structural diagram of the optical communication system in embodiment 11.

[0022] Figure 14 This is a structural diagram showing another optical communication system in embodiment 11.

[0023] Figure 15 This is a structural diagram of the optical communication system in embodiment 12. Detailed Implementation

[0024] Hereinafter, in order to illustrate this disclosure in more detail, the manner in which this disclosure is carried out will be described with reference to the accompanying drawings.

[0025] Implementation method 1.

[0026] Figure 1 This is a structural diagram of the optical communication system in Implementation Method 1.

[0027] Figure 1 The optical communication system shown includes: a communication device 1, a peer device 2, a first optical fiber 3, an optical amplifier 4, a second optical fiber 5, an optical amplifier 6, a first bypass optical fiber 7, a second bypass optical fiber 8, and a sensor device 9.

[0028] The communication device 1 includes an optical transmitter for transmitting communication light and an optical receiver for receiving communication light.

[0029] The peer device 2 is a communication device that communicates with the communication device 1 by transmitting and receiving optical signals.

[0030] The peer device 2 includes an optical receiver for receiving communication light transmitted from the communication device 1 and an optical transmitter for transmitting communication light to the communication device 1.

[0031] The first optical fiber 3 is, for example, realized by a single-core or multi-core wire of a single-mode or multi-mode optical fiber.

[0032] One end of the first optical fiber 3 is connected to the communication device 1, and the other end of the first optical fiber 3 is connected to the peer device 2.

[0033] The first optical fiber 3 is a communication optical fiber used to transmit communication light sent from the communication device 1 to the other end device 2.

[0034] An optical amplifier 4 is inserted into the first optical fiber 3.

[0035] Optical amplifier 4 is implemented, for example, by an erbium-doped fiber amplifier (EDFA) or a semiconductor optical amplifier (SOA).

[0036] Optical amplifier 4 amplifies the communication light transmitted from communication device 1 and outputs the amplified communication light to the other end device 2.

[0037] The second optical fiber 5 is, for example, implemented by a single-core or multi-core wire of a single-mode or multi-mode optical fiber.

[0038] One end of the second optical fiber 5 is connected to the communication device 1, and the other end of the second optical fiber 5 is connected to the peer device 2.

[0039] The second optical fiber 5 is a communication optical fiber used to transmit communication light sent from the peer device 2 to the communication device 1.

[0040] An optical amplifier 6 is inserted into the second optical fiber 5.

[0041] Optical amplifier 6 is implemented, for example, by EDFA or SOA.

[0042] Optical amplifier 6 amplifies the communication light sent from peer device 2 and outputs the amplified communication light to communication device 1.

[0043] The first bypass uses optical fibers 7-1 to 7-G, for example, single-core or multi-core wires of single-mode or multi-mode optical fibers, respectively. G is an integer greater than 2.

[0044] The first bypass fiber 7-g (g=1,…,G) is used to bypass the optical amplifier 4 inserted into the first fiber 3.

[0045] Specifically, one end of the first bypass fiber 7-g is connected to the input side of the optical amplifier 4, and the other end of the first bypass fiber 7-g is connected to the output side of the optical amplifier 4.

[0046] The second bypass uses optical fibers 8-1 to 8-G, for example, single-core or multi-core wires of single-mode or multi-mode optical fibers.

[0047] The second bypass fiber 8-g is used to bypass the optical amplifier 6 inserted into the second fiber 5.

[0048] Specifically, one end of the second bypass fiber 8-g is connected to the input side of the optical amplifier 6, and the other end of the second bypass fiber 8-g is connected to the output side of the optical amplifier 6.

[0049] The sensor device 9 includes: an optical transmitter that transmits sensor light, an optical receiver that receives backscattered light from the sensor light, and a detection unit that senses either the first optical fiber 3 or the second optical fiber 5 based on the backscattered light.

[0050] The sensor device 9 sends sensor light to either the first optical fiber 3 or the second optical fiber 5, and receives backscattered light returned from either the first optical fiber 3 or the second optical fiber 5.

[0051] The sensor device 9 senses either the first optical fiber 3 or the second optical fiber 5 based on backscattered light.

[0052] Next, regarding Figure 1 The operation of the optical communication system shown is explained.

[0053] When communication device 1 sends communication light to peer device 2, communication device 1 sends the communication light out to the first optical fiber 3.

[0054] The communication light sent to the first optical fiber 3 is amplified by the optical amplifier 4, and the amplified communication light reaches the other end device 2.

[0055] Therefore, the peer device 2 receives the communication light sent from the communication device 1.

[0056] When the peer device 2 sends communication light to the communication device 1, the peer device 2 sends the communication light out to the second optical fiber 5.

[0057] The communication light sent to the second optical fiber 5 is amplified by the optical amplifier 6, and the amplified communication light reaches the communication device 1.

[0058] Thus, communication device 1 receives communication light transmitted from peer device 2.

[0059] The first optical fiber 3 and the second optical fiber 5 may each change, for example, due to changes in the surrounding environment or over time. These changes may include, for example, temperature changes, vibration changes, stress changes, or changes in light loss.

[0060] When the sensor device 9 senses the first optical fiber 3, it sends sensor light to the first optical fiber 3.

[0061] The sensor light sent to the first optical fiber 3 is scattered by the first optical fiber 3, and the backscattered light of the sensor light returns to the sensor device 9. The backscattered light of the sensor light is the scattered light corresponding to the change in the first optical fiber 3.

[0062] As the backscattered light of the sensor light, such as Figure 2 As shown, there are, for example, Rayleigh scattering, Brillouin scattering, or Raman scattering.

[0063] Figure 2 This is an explanatory diagram showing the spectral images of the sensor light and the backscattered light, respectively.

[0064] Figure 2 The horizontal axis represents the wavelength. Figure 2 The spectra of the sensor light and the backscattered light are shown.

[0065] Because the light propagation direction of the optical amplifier 4 inserted into the first optical fiber 3 is unidirectional, the backscattered light from the sensor cannot pass through the optical amplifier 4. However, due to... Figure 1 The optical communication system shown is provided with first bypass optical fibers 7-1 to 7-G for bypassing the optical amplifier 4, so that the backscattered light of the sensor light can return to the sensor device 9 via any one of the first bypass optical fibers 7-1 to 7-G.

[0066] The sensor device 9 receives the backscattered light returned from the first optical fiber 3 and senses the first optical fiber 3 based on the backscattered light.

[0067] The sensing technology of sensor device 9 is well-known, so detailed description is omitted.

[0068] When the sensor device 9 senses the second optical fiber 5, sensor light is sent to the second optical fiber 5.

[0069] The sensor light transmitted to the second optical fiber 5 is scattered by the second optical fiber 5, and the backscattered light of the sensor light returns to the sensor device 9. The backscattered light of the sensor light is the scattered light corresponding to the change in the second optical fiber 5.

[0070] Because the light propagating in the optical amplifier 6 inserted into the second optical fiber 5 is unidirectional, the sensor light cannot pass through the optical amplifier 6. However, due to... Figure 1 The optical communication system shown is provided with second bypass optical fibers 8-1 to 8-G for bypassing the optical amplifier 6, so that the sensor light can be transmitted to the other end device 2 via any one of the second bypass optical fibers 8-1 to 8-G.

[0071] The sensor device 9 receives the backscattered light returned from the second optical fiber 5 and senses the second optical fiber 5 based on the backscattered light.

[0072] Figure 1 The optical communication system shown has G first bypass optical fibers 7-1 to 7-G and G second bypass optical fibers 8-1 to 8-G.

[0073] The first bypass using optical fiber 7-1~7-G can also be: the wavelengths of the propagating sensor light are different from each other, and the wavelengths of the propagating backscattered light are different from each other.

[0074] Alternatively, the second bypass fiber 8-1~8-G can also be: the wavelengths of the propagating sensor light are different from each other, and the wavelengths of the propagating backscattered light are different from each other.

[0075] In this case, if the sensor device 9 sends multiple sensor lights with different wavelengths to the first optical fiber 3 in order to detect multiple changes, then any one of the first bypass optical fibers 7-1 to 7-G can allow any one of the sensor lights to pass through.

[0076] Similarly, if the sensor device 9 sends multiple sensor lights with different wavelengths to the second optical fiber 5 in order to detect various changes, any one of the second bypass optical fibers 8-1 to 8-G can allow any one of the sensor lights to pass through.

[0077] For example, it can be configured such that the sensor light for detecting temperature changes passes through the first bypass fiber 7-1 and the second bypass fiber 8-1, respectively, and the backscattered light of the sensor light passes through the first bypass fiber 7-1 and the second bypass fiber 8-1, respectively.

[0078] For example, it can be configured such that the sensor light for detecting vibration changes passes through a first bypass fiber 7-G and a second bypass fiber 8-G, respectively, and the backscattered light of the sensor light passes through the first bypass fiber 7-G and the second bypass fiber 8-G, respectively.

[0079] In Embodiment 1 described above, an optical communication system is configured as follows: a first optical fiber 3 that transmits communication light from communication device 1 to peer device 2; a second optical fiber 5 that transmits communication light from peer device 2 to communication device 1; a plurality of first bypass optical fibers 7-1 to 7-G that bypass an optical amplifier 4 inserted into the first optical fiber 3; and a plurality of second bypass optical fibers 8-1 to 8-G that bypass an optical amplifier 6 inserted into the second optical fiber 5. Furthermore, the optical communication system includes a sensor device 9 that transmits sensor light to either the first optical fiber 3 or the second optical fiber 5 and receives backscattered light returning from either the first optical fiber 3 or the second optical fiber 5. Therefore, the optical communication system can sense the communication optical fiber without laying a sensing optical fiber connecting communication device 1 and peer device 2.

[0080] exist Figure 1 In the optical communication system shown, sensor device 9 is configured on the communication device 1 side. However, this is only an example, and sensor device 9 can also be configured on the peer device 2 side. Even in this case, it is possible to sense the communication fiber without laying the sensing fiber connecting the communication device 1 and the peer device 2.

[0081] Figure 1 The optical communication system shown includes a first optical fiber 3, a second optical fiber 5, a first bypass optical fiber 7-1 to 7-G, and a second bypass optical fiber 8-1 to 8-G.

[0082] Figure 1 The optical communication system shown also includes a structure that adds a first bypass fiber 7-1 to 7-G, a second bypass fiber 8-1 to 8-G, and a sensor device 9 to an optical communication system having a first fiber 3 and a second fiber 5 already installed.

[0083] Implementation method 2.

[0084] In Embodiment 2, an optical communication system having N (N is an integer of 2 or more) peer devices 2 will be described.

[0085] Figure 3 This is a structural diagram showing the optical communication system of Embodiment 2. Figure 3 Zhongyu Figure 1 The same reference numerals denote the same or equivalent parts, therefore detailed descriptions are omitted.

[0086] Figure 3 The optical communication system shown includes: a communication device 1, peer devices 2-1 to 2-N, a first optical fiber 3, a branched first optical fiber 3-1 to 3-N, an optical amplifier 4-1 to 4-N, a second optical fiber 5, a branched second optical fiber 5-1 to 5-N, an optical amplifier 6-1 to 6-N, a first bypass optical fiber 7-1-1 to 7-NG, a second bypass optical fiber 8-1-1 to 8-NG, a sensor device 9, and an optical path switching device 10.

[0087] The counterpart devices 2-1 to 2-N respectively have the same characteristics as... Figure 1 The communication device shown is the same as the peer device 2.

[0088] The first optical fiber 3 is branched into N branches by the optical path switching device 10, and the branched first optical fibers 3-n (n=1,…,N) are connected to the opposite end device 2-n.

[0089] An optical amplifier 4-n is inserted into the first optical fiber 3-n after the branch.

[0090] Optical amplifier 4-n is implemented, for example, by EDFA or SOA.

[0091] Optical amplifier 4-n amplifies the communication light output from optical path switching device 10 and outputs the amplified communication light to the other end device 2-n.

[0092] The second optical fiber 5 is branched into N branches by the optical path switching device 10, and the branched second optical fiber 5-n is connected to the counterpart device 2-n.

[0093] An optical amplifier 6-n is inserted into the second optical fiber 5-n after the branch.

[0094] Optical amplifier 6-n is implemented, for example, by EDFA or SOA.

[0095] Optical amplifier 6-n amplifies the communication light transmitted from the peer device 2-n and outputs the amplified communication light to optical path switching device 10.

[0096] The first bypass is implemented using optical fibers 7-1-1 to 7-NG, for example, single-core or multi-core wires of single-mode or multi-mode optical fibers.

[0097] The first bypass fiber 7-ng (g=1,…,G) is used to bypass the optical amplifier 4-n inserted into the first fiber 3-n.

[0098] Specifically, one end of the first bypass fiber 7-ng is connected to the input side of the optical amplifier 4-n, and the other end of the first bypass fiber 7-ng is connected to the output side of the optical amplifier 4-n.

[0099] The second bypass uses optical fibers 8-1-1 to 8-NG, for example, single-core or multi-core wires of single-mode or multi-mode optical fibers.

[0100] The second bypass fiber 8-ng is used to bypass the optical amplifier 6-n inserted into the second fiber 5-n.

[0101] Specifically, one end of the second bypass fiber 8-ng is connected to the input side of the optical amplifier 6-n, and the other end of the second bypass fiber 8-ng is connected to the output side of the optical amplifier 6-n.

[0102] The optical path switching device 10 is implemented, for example, by a wavelength selective switch (WSS).

[0103] The optical path switching device 10 outputs the communication light sent from the communication device 1 to any one of the branched first optical fibers 3-n (from 3-1 to 3-N) to any one of the N peer devices 2-1 to 2-N.

[0104] The optical path switching device 10 outputs the communication light propagated from any peer device 2-n through the branched second optical fiber 5-n to the communication device 1.

[0105] Next, regarding Figure 3 The operation of the optical communication system shown is explained.

[0106] exist Figure 3 In the optical communication system shown, the wavelengths of the communication light from the N peer devices 2-1 to 2-N are as follows: Figure 4 The wavelengths shown are different. For example, the wavelength of the communication light from the other end device 2-1 is λ. 1，1 ~λ 1，G The wavelength of the communication light of the peer device 2-(N-1) is, for example, λ. K - 1，1 ~λ K-1，G The wavelength of the communication light of the peer device 2-N is, for example, λ. K，1 ~λ K，G Alternatively, N can be equal to K, or N can be not equal to K. In the case where N is not equal to K, for example, N < K.

[0107] Figure 4 This is an explanatory diagram showing the wavelengths of communication light for N peer devices 2-1 to 2-N.

[0108] exist Figure 4 The horizontal axis represents wavelength. Figure 4 In the example, λ 1，1 <...<λ K，G-1 <λ K，G .

[0109] Figure 4 The example shown is a communication optical signal of 128 Gbit / s (32 GBd DP-QPSK) with a single wavelength channel width of 50 GHz-grid.

[0110] In the example above, when communication device 1 sends communication light to peer device 2-1, the wavelength λ is... 1，1 ~λ 1，G One or more communication light outputs are sent to the optical path switching device 10. When sending communication light to the peer device 2-(N-1), the wavelength λ is switched. K - 1，1 ~λ K - 1，G One or more communication optical outputs are sent to the optical path switching device 10. When sending communication optical to the peer device 2-N, the wavelength λ is switched. K，1 ~λ K，G One or more of the communication optical outputs are sent to the optical path switching device 10.

[0111] When communication device 1 transmits communication light to all N peer devices 2-1 to 2-N, the light will include wavelength λ. 1，g (g=1,…,G),…,λ K，g The communication light, including the communication light, is output to the optical path switching device 10.

[0112] If the optical path switching device 10 receives communication light from the communication device 1, then if the communication light contains wavelength λ 1，g Communication light, by using wavelength λ 1，g The communication light is sent out to the first optical fiber 3-1-g after branching, thereby transmitting the wavelength λ 1，g The communication optical output is sent to the other end device 2-1.

[0113] If the communication light output from communication device 1 contains wavelength λ K - 1，g The communication light, then the optical path switching device 10 switches the wavelength λ K - 1，g The communication light is sent out to the first optical fiber 3-(N-1)-g after branching, thereby transmitting the wavelength λ K - 1，g The communication optical output is sent to the peer device 2-(N-1).

[0114] If the communication light output from communication device 1 contains wavelength λ K，g The communication light, then the optical path switching device 10 switches the wavelength λ K，g The communication light is sent out to the first optical fiber 3-Ng after branching, thereby transmitting the wavelength λ K，g The communication optical output is sent to the peer device 2-N.

[0115] The counterpart device 2-n (n=1,…,N) uses wavelength λ k，g The communication light is transmitted to the second optical fiber 5-ng after branching, thereby transmitting the wavelength λ. k，g The communication optical output is sent to the optical path switching device 10. k can be any number from 1 to K.

[0116] If the optical path switching device 10 receives wavelength λ from the other end device 2-n k，g Communication light, by using wavelength λ k，g The communication light is sent to the second optical fiber 5, thereby transmitting the wavelength λ. k，g The communication optical output is sent to communication device 1.

[0117] For example, if the optical path switching device 10 receives communication light from N peer devices 2-1 to 2-N, it can switch the optical path by including wavelength λ. 1，g , …, λ K The communication light, including the communication light of g, is sent to the second optical fiber 5, thereby outputting the communication light to the communication device 1.

[0118] exist Figure 3 In the optical communication system shown, the wavelengths of the sensor light from the N peer devices 2-1 to 2-N are different from each other. For example, the wavelength of the sensor light from peer device 2-1 is λ. 1，1 '~λ 1，G The wavelength of the sensor light in the counterpart device 2-(N-1) is, for example, λ. K - 1，1 '~λ K - 1，G The wavelength of the sensor light in the counterpart device 2-N is, for example, λ. K，1 '~λ K，G For example, λ 1，1 '<…<λ K，g '<λ 1，1 <...<λ K，g , or λ 1，1 <...<λ K，g <λ 1，1 '<…<λ K，g '.

[0119] When the sensor device 9 senses the first optical fiber 3-n (n=1,…,N) after branching, the wavelength λ will be... k，g The sensor light is sent out to the first optical fiber 3.

[0120] The wavelength λ sent to the first optical fiber 3 k，g The sensor light is sent out by the optical path switching device 10 to the first optical fiber 3-n after branching.

[0121] The sensor light sent to the first optical fiber 3-n after the branch is scattered by the first optical fiber 3-n after the branch, and the backscattered light of the sensor light returns to the optical path switching device 10.

[0122] The optical path switching device 10 sends the backscattered light to the first optical fiber 3, thereby outputting the backscattered light to the sensor device 9.

[0123] Because the light propagation direction of the optical amplifier 4-n, which is inserted into the first optical fiber 3-n after the branch, is unidirectional, the backscattered light from the sensor cannot pass through the optical amplifier 4-n. However, due to Figure 3 The optical communication system shown is provided with a first bypass fiber 7-ng for bypassing the optical amplifier 4-n, so that the backscattered light of the sensor light can return to the sensor device 9 via the first bypass fiber 7-ng.

[0124] The sensor device 9 receives the backscattered light output from the optical path switching device 10 and senses the first optical fiber 3-n after branching based on the backscattered light.

[0125] When sensor device 9 senses the second optical fiber 5-n after branching, the wavelength λ k-g The sensor light is sent out to the second optical fiber 5.

[0126] The sensor light sent to the second optical fiber 5 is sent out by the optical path switching device 10 to the branched second optical fiber 5-n.

[0127] The sensor light sent to the second optical fiber 5-n after branching is scattered by the second optical fiber 5-n after branching, and the backscattered light of the sensor light returns to the optical path switching device 10.

[0128] The optical path switching device 10 sends the backscattered light to the second optical fiber 5, thereby outputting the backscattered light to the sensor device 9.

[0129] Because the light propagation direction of the optical amplifier 6-n after the insertion of the branch is unidirectional, the sensor light cannot pass through the optical amplifier 6-n. However, in Figure 3 The optical communication system shown is equipped with a second bypass fiber 8-ng for bypassing the optical amplifier 6-n, so that the sensor light can propagate to the other end device 2-n via the second bypass fiber 8-ng.

[0130] The sensor device 9 receives the backscattered light output from the optical path switching device 10 and senses the branched second optical fiber 5-n based on the backscattered light.

[0131] In Embodiment 2 above, the optical communication system is configured such that there are N peer devices 2 (N being an integer greater than or equal to 2) and an optical path switching device 10 is provided. This optical path switching device 10 branches the first optical fiber 3 and the second optical fiber 5 into N branches respectively, and connects them to each peer device 2-n via the branched first optical fiber 3-n and the branched second optical fiber 5-n respectively. Furthermore, the optical communication system includes: a plurality of first bypass optical fibers 7-n-1 to 7-nG serving as first bypass optical fibers 7-g, which bypass the optical amplifier 4-n inserted into each branched first optical fiber 3-n; and a plurality of second bypass optical fibers 8-n-1 to 8-nG serving as second bypass optical fibers 8-g, which bypass the optical amplifier 6-n inserted into each branched second optical fiber 5-n. Therefore, even with N peer devices 2-1 to 2-N, the optical communication system can sense the communication optical fiber without laying a sensing optical fiber connecting the communication device 1 to the peer devices 2-1 to 2-N.

[0132] Implementation method 3.

[0133] In embodiment 3, an optical communication system having M (M is an integer of 2 or more) communication devices 1 will be described.

[0134] Figure 5 This is a structural diagram illustrating the optical communication system of Embodiment 3. Figure 5 Zhongyu Figure 1 and Figure 3 The same reference numerals denote the same or equivalent parts, therefore detailed descriptions are omitted.

[0135] Figure 5 The optical communication system shown includes: communication devices 1-1~1-M, peer devices 2-1~2-N, first optical fibers 3-1'~3-M', first optical fibers after branching 3-1~3-N, optical amplifiers 4-1~4-N, second optical fibers 5-1'~5-M', second optical fibers after branching 5-1~5-N, optical amplifiers 6-1~6-N, first bypass optical fibers 7-1-1~7-NG, second bypass optical fibers 8-1-1~8-NG, sensor devices 9, optical path switching devices 10, and optical wavelength division multiplexing and demultiplexing devices 11.

[0136] Communication devices 1-1 to 1-M respectively have the same as Figure 1 The communication device 1 shown has the same function.

[0137] The communication device 1-m (m=1, ..., M) is connected to the optical wave splitter 11 via the first optical fiber 3-m'.

[0138] In addition, the communication device 1-m is connected to the optical wave combiner / demultiplexer 11 via the second optical fiber 5-m'.

[0139] The first optical fiber 3-1'~3-M' is, for example, realized by a single-core wire or a multi-core wire of a single-mode optical fiber or a multi-mode optical fiber, respectively.

[0140] One end of the first optical fiber 3-m is connected to the communication device 1-m, and the other end of the first optical fiber 3-m is connected to the optical wave combiner / demultiplexer 11.

[0141] The second optical fiber 5-1' to 5-M' is, for example, realized by a single-core or multi-core wire of a single-mode optical fiber or a multi-mode optical fiber, respectively.

[0142] One end of the second optical fiber 5-m is connected to the communication device 1-m, and the other end of the second optical fiber 5-m is connected to the optical wave combiner / demultiplexer 11.

[0143] The optical wave-splitting device 11 is implemented, for example, by a combination of multiplexers and demultiplexers, an arrayed waveguide grating (AWG), or a WSS.

[0144] The optical combining and splitting device 11 combines the communication optical waves sent from any one or more of the M communication devices 1-1 to 1-M, and outputs the combined communication light to the optical path switching device 10.

[0145] The optical wave splitter 11 splits the communication light output from the optical path switching device 10 and outputs each split communication light to any one of the M communication devices 1-1 to 1-M, 1-m.

[0146] exist Figure 5 In the optical communication system shown, the wavelengths of the communication light from the N peer devices 2-1 to 2-N and the M communication devices 1-1 to 1-M are all different. The wavelength of the communication light from the peer devices 2-n (n=1, ..., N) and the communication devices 1-m (m=1, ..., M) is λ. m-k，1 ~λ m-k，g Specifically, the wavelength of the communication light of the communication device 1-1 of the peer device 2-1 is, for example, λ. 1-1，1 ~λ 1-1，G The wavelength of the communication light of the communication device 1-M of the peer device 2-N is, for example, λ. M-K，1 ~λ M-K，G .

[0147] When communication device 1-m (m=1, ..., M) transmits communication light to peer device 2-n (n=1, ..., N), the wavelength λ is transmitted via the first optical fiber 3-m'. m-k，g The communication light is sent to the optical wave combiner / demultiplexer 11.

[0148] The optical wave splitter 11 can transmit a communication optical wave from any one or more of the M communication devices 1-1 to 1-M, namely the communication optical wave 1-m.

[0149] The optical combining and splitting device 11 outputs the combined communication light to the optical path switching device 10.

[0150] If the optical path switching device 10 receives the combined communication light from the optical multiplexing and demultiplexing device 11, then if the combined communication light contains wavelength λ m-k，g Communication light, by using wavelength λ m-k，g The communication light is sent out to the first optical fiber 3-n after the branch, thereby transmitting the wavelength λ. m-k，g The communication optical output is sent to the peer device 2-n.

[0151] The counterpart device 2-n passes the wavelength λ m-k，g The communication light is sent out to the second optical fiber 5-n, thereby transmitting the wavelength λ. m-k，g The communication optical signal is transmitted to the optical path switching device 10.

[0152] If the optical path switching device 10 receives wavelength λ from the other end device 2-n m-k，g The communication light will then have a wavelength λ m-k，g The communication optical output is sent to the optical wavelength division multiplexing device 11.

[0153] If the optical wavelength splitter 11 receives wavelength λ from the optical path switching device 10 m-k，g Communication light, by using wavelength λ m-k，g The communication light is transmitted to the second optical fiber 5-m', thereby transmitting the wavelength λ. m-k，g The communication optical output is sent to the communication device 1-m.

[0154] exist Figure 5 In the optical communication system shown, the wavelengths of the sensor light from the M communication devices 1-1 to 1-M of the N peer devices 2-1 to 2-N are different from each other. The wavelength of the sensor light from the communication device 1-m (m=1, ..., M) of the peer devices 2-n (n=1, ..., N) is λ. m-k，g Specifically, the wavelength of the sensor light of the communication device 1-1 of the peer device 2-1 is, for example, λ1- 1，g The wavelength of the sensor light in the communication device 1-M of the peer device 2-N is, for example, λ. M-K，g '.

[0155] When the sensor device 9 senses the first optical fiber 3-n (n=1,…,N) after branching, the wavelength λ will be... m-k，g The sensor light is sent out to the first optical fiber 3-m.

[0156] The wavelength λ sent to the first optical fiber 3-m m-k，gThe sensor light is output to the optical path switching device 10 via the optical wavelength splitter 11, with a wavelength λ. m-k，g The sensor light is sent out by the optical path switching device 10 to the first optical fiber 3-n after branching.

[0157] The sensor light sent to the first optical fiber 3-n after the branch is scattered by the first optical fiber 3-n after the branch, and the backscattered light of the sensor light returns to the optical path switching device 10.

[0158] The optical path switching device 10 outputs the backscattered light to the optical combining and splitting device 11.

[0159] The optical wave-splitting device 11 outputs backscattered light to the sensor device 9 by sending the backscattered light to the first optical fiber 3-m'.

[0160] The sensor device 9 receives the backscattered light output from the optical wave splitter 11 and senses the first optical fiber 3-n after branching based on the backscattered light.

[0161] When sensor device 9 senses the second optical fiber 5-n after branching, the wavelength λ m-k，g The sensor light is sent out to the second optical fiber 5-n.

[0162] The sensor light sent to the second optical fiber 5 is output to the optical path switching device 10 via the optical wavelength division multiplexing and splitting device 11, with a wavelength λ. m-k，g The sensor light is sent out by the optical path switching device 10 to the second optical fiber 5-n after branching.

[0163] The sensor light sent to the second optical fiber 5-n after branching is scattered by the second optical fiber 5-n after branching, and the backscattered light of the sensor light returns to the optical path switching device 10.

[0164] The optical path switching device 10 outputs the backscattered light to the optical combining and splitting device 11.

[0165] The optical wave-splitting device 11 outputs backscattered light to the sensor device 9 by sending the backscattered light to the second optical fiber 5-m'.

[0166] The sensor device 9 receives the backscattered light output from the optical wave splitter 11 and senses the branched second optical fiber 5-n based on the backscattered light.

[0167] In the above-described embodiment 3, the optical communication system is configured such that there are M communication devices (M being an integer of 2 or more), and includes an optical multiplexing / demultiplexing device 11. This optical multiplexing / demultiplexing device 11 combines communication light transmitted from any one or more of the M communication devices 1-1 to 1-M, outputs the combined communication light to an optical path switching device 10, and demultiplexes the communication light output from the optical path switching device 10, outputting each demultiplexed communication light to any one of the M communication devices 1-1 to 1-M. Therefore, even with M communication devices 1-1 to 1-M, the optical path switching device 10 can sense the communication optical fiber without laying the sensing optical fiber connecting the communication devices 1-1 to 1-M to the peer devices 2-1 to 2-N.

[0168] Implementation method 4.

[0169] In Embodiment 4, an optical communication system having P (P being an integer greater than or equal to 2) sensor devices 9-1 to 9-P will be described.

[0170] Figure 6 This is a structural diagram of the optical communication system in Embodiment 4. Figure 6 Zhongyu Figure 1 , Figure 3 and Figure 5 The same reference numerals denote the same or equivalent parts, therefore detailed descriptions are omitted.

[0171] Figure 6 The optical communication system shown includes: communication devices 1-1~1-M, peer devices 2-1~2-N, first optical fibers 3-1'~3-M', first optical fibers after branching 3-1~3-N, optical amplifiers 4-1~4-N, second optical fibers 5-1'~5-M', second optical fibers after branching 5-1~5-N, optical amplifiers 6-1~6-N, first bypass optical fibers 7-1-1~7-NG, second bypass optical fibers 8-1-1~8-NG, sensor devices 9-1~9-P, optical path switching device 10, and optical wavelength division multiplexing and demultiplexing device 11.

[0172] Sensor devices 9-1 to 9-P respectively possess the same as Figure 1 The sensor device 9 shown has the same function.

[0173] Sensor device 9-1, for example, emits sensor light for detecting temperature changes; sensor device 9-2, for example, emits sensor light for detecting vibration changes; and sensor device 9-P, for example, emits sensor light for detecting stress changes. The wavelengths of these P sensor lights are all different from each other.

[0174] Next, regarding Figure 6The operation of the optical communication system shown will be explained. However, apart from sensor devices 9-1 to 9-P, the operation of the optical communication system will also be explained. Figure 5 The same applies to the optical communication system shown. Therefore, the operation of sensor devices 9-1 to 9-P will be mainly explained here.

[0175] When sensing the first optical fiber 3-n (n=1, ..., N) after branching, any one of the P sensor devices 9-p (p=1, ..., P) sends the sensor light to the optical wave combiner / demultiplexer 11 by sending the sensor light out to the first optical fiber 3-m (m=1, ..., M).

[0176] For example, when a temperature change is detected in the first optical fiber 3-n after branching, sensor device 9-1 sends out sensor light; for example, when a vibration change is detected in the first optical fiber 3-n after branching, sensor device 9-2 sends out sensor light.

[0177] The optical wave splitter 11 outputs the sensor light sent from the sensor device 9-p to the optical path switching device 10, and outputs the backscattered light of the sensor light output from the optical path switching device 10 to the sensor device 9-p.

[0178] The sensor device 9-p receives the backscattered light output from the optical wave splitter 11 and senses the first optical fiber 3-n after branching based on the backscattered light.

[0179] When sensing the second optical fiber 5-n after branching, any one of the P sensor devices 9-1 to 9-P sends the sensor light to the optical wave combiner / demultiplexer 11 by sending the sensor light out to the second optical fiber 5-m.

[0180] For example, when detecting a temperature change in the second optical fiber 5-n after branching, sensor device 9-1 sends out sensor light; when detecting a vibration change in the second optical fiber 5-n after branching, sensor device 9-2 sends out sensor light.

[0181] The optical wave splitter 11 outputs the sensor light sent from the sensor device 9-p to the optical path switching device 10, and outputs the backscattered light of the sensor light output from the optical path switching device 10 to the sensor device 9-p.

[0182] Sensor device 9-p receives backscattered light output from optical wave combining and splitting device 11, and senses the branched second optical fiber 5-n based on the backscattered light.

[0183] In the above-described embodiment 4, the optical communication system is configured such that there are P (P being an integer of 2 or more) sensor devices 9, and a wavelength division multiplexing (WDM) device 11 is provided. This WDM device 11 outputs sensor light transmitted from each of the P sensor devices to an optical path switching device 10, and outputs backscattered light from the optical path switching device 10 to sensor device 9-p. Therefore, the optical communication system can not only sense the communication optical fiber without laying the sensing optical fiber connecting the communication devices 1-1 to 1-M and the peer devices 2-1 to 2-N, but also detect various changes in the communication optical fiber.

[0184] Implementation method 5.

[0185] In Embodiment 5, the following optical communication system will be described, wherein the optical wavelength division device 12 outputs backscattered light within the passing band of the backscattered light output from the optical path switching device 10 to the sensor device 9, and blocks backscattered light outside the passing band.

[0186] Figure 7 This is a structural diagram showing the optical communication system of Embodiment 5. Figure 7 Zhongyu Figure 1 , Figure 3 , Figure 5 and Figure 6 The same reference numerals denote the same or equivalent parts, therefore detailed descriptions are omitted.

[0187] Figure 7 The optical communication system shown includes: communication devices 1-1~1-M, peer devices 2-1~2-N, first optical fibers 3-1'~3-M', first optical fibers after branching 3-1~3-N, optical amplifiers 4-1~4-N, second optical fibers 5-1'~5-M', second optical fibers after branching 5-1~5-N, optical amplifiers 6-1~6-N, first bypass optical fibers 7-1-1~7-NG, second bypass optical fibers 8-1-1~8-NG, sensor devices 9, optical path switching devices 10, and optical wavelength division multiplexing and demultiplexing devices 12.

[0188] The optical wavelength division multiplexing device 12 is implemented, for example, by a combination of a multiplexer and a demultiplexer, an AWG, or a WSS.

[0189] and Figure 5 Similarly, the optical wave combiner and splitter 12 can combine the communication optical waves sent from any one or more of the M communication devices 1-1 to 1-M, and output the combined communication light to the optical path switching device 10.

[0190] The optical wave splitter 12 splits the communication light output from the optical path switching device 10 and outputs each split communication light to any one of the M communication devices 1-1 to 1-M, 1-m.

[0191] and Figure 5 Unlike the optical wave splitter 11 shown, the optical wave splitter 12 outputs the backscattered light within the passing band of the backscattered light output from the optical path switching device 10 to the sensor device 9, and blocks the backscattered light outside the passing band.

[0192] exist Figure 7 In the optical communication system shown, the optical wavelength division multiplexing and demultiplexing device 12 is applied to... Figure 5 The optical communication system shown is just one example; the optical wavelength division multiplexing / demultiplexing device 12 can also be applied to other systems. Figure 6 The optical communication system shown.

[0193] Next, regarding Figure 7 The operation of the optical communication system shown will be explained. However, apart from the optical wavelength division multiplexing and demultiplexing device 12, and... Figure 5 The optical communication system shown is the same. Therefore, only the operation of the optical wavelength division multiplexing device 12 will be described here.

[0194] When sensing the first fiber 3-n (n=1, ..., N) after branching, or when sensing the second fiber 5-n after branching, the optical combining and splitting device 12 acquires the backscattered light output from the optical path switching device 10.

[0195] The optical wave combiner / splitter 12 may include, for example, a bandpass filter with a desired passband. Alternatively, the optical wave combiner / splitter 12 may be wavelength-selected to have a desired passband via a WSS.

[0196] The optical wave splitter 12 applies backscattered light to a bandpass filter or WSS. If the backscattered light output from the optical path switching device 10 is a backscattered light within the band, the backscattered light output from the optical path switching device 10 is output to the sensor device 9.

[0197] If the backscattered light output from the optical path switching device 10 is backscattered light outside the wavelength band, the optical combining and splitting device 12 blocks the backscattered light output from the optical path switching device 10.

[0198] In the above-described embodiment 5, the optical communication system is configured such that the optical wavelength division multiplexing device 12 outputs backscattered light within the passing band from the backscattered light output from the optical path switching device 10 to the sensor device 9, and blocks backscattered light outside the passing band. Therefore, the optical communication system can not only sense the communication optical fiber without laying the sensing optical fiber connecting the communication devices 1-1 to 1-M and the peer devices 2-1 to 2-N, but also prevents the degradation of sensing accuracy due to noise, etc.

[0199] Implementation method 6.

[0200] In embodiment 6, an optical communication system comprising a first optical wave combiner 11a and a second optical wave combiner 11b will be described.

[0201] Figure 8 This is a structural diagram showing the optical communication system of Embodiment 6. Figure 8 Zhongyu Figure 1 , Figure 3 and Figures 5 to 7 The same reference numerals denote the same or equivalent parts, therefore detailed descriptions are omitted.

[0202] Figure 8 The optical communication system shown includes: communication devices 1-1~1-M, peer devices 2-1~2-N, first optical fibers 3-1'~3-M', first optical fibers after branching 3-1~3-N, optical amplifiers 4-1~4-N, second optical fibers 5-1'~5-M', second optical fibers after branching 5-1~5-N, optical amplifiers 6-1~6-N, first bypass optical fibers 7-1-1~7-NG, second bypass optical fibers 8-1-1~8-NG, sensor devices 9-1~9-P, optical path switching device 10, first optical multiplexer / demultiplexer 11a, and second optical multiplexer / demultiplexer 11b.

[0203] The first optical wavelength division multiplexer 11a is implemented, for example, by a combination of a multiplexer and a demultiplexer, an AWG, or a WSS.

[0204] The first optical multiplexer 11a combines the communication optical waves sent from any one or more of the M communication devices 1-1 to 1-M, and outputs the combined communication light to the optical path switching device 10.

[0205] The first optical wave combiner / demultiplexer 11a demultiplexes the communication light output from the optical path switching device 10 and outputs each demultiplexed communication light to any one of the M communication devices 1-1 to 1-M, 1-m.

[0206] The second optical wavelength division multiplexer 11b is implemented, for example, by a combination of a multiplexer and a demultiplexer, an AWG, or a WSS.

[0207] The second optical wave combiner / demultiplexer 11b outputs sensor light from any one or more of the P sensor devices 9-p (p=1, ..., P) from sensor devices 9-1 to 9-P to the optical path switching device 10.

[0208] The second optical wave combiner / demultiplexer 11b outputs the backscattered light of the sensor light from the optical path switching device 10 to the sensor device 9-n, the source of the sensor light.

[0209] exist Figure 8 In the optical communication system shown, the first optical multiplexer 11a and the second optical multiplexer 11b are used in... Figure 6 The optical communication system shown includes an optical multiplexer / demultiplexer 11. However, this is only one example; the first optical multiplexer / demultiplexer 11a and the second optical multiplexer / demultiplexer 11b can also be applied to... Figure 5 The optical communication system shown has an optical wavelength division multiplexing and demultiplexing device 11 or Figure 7 The optical communication system shown has an optical wavelength division multiplexing and demultiplexing device 12.

[0210] exist Figure 8 In the optical communication system shown, the optical multiplexing and demultiplexing device 11 includes a second optical multiplexing and demultiplexing device 11b, which is separately disposed from the first optical multiplexing and demultiplexing device 11a used for multiplexing and demultiplexing communication light and is used for multiplexing sensor light and demultiplexing backscattered light.

[0211] Therefore, for Figure 8 In the optical communication system shown, compared with the case of an optical multiplexer that can be used for both communication light multiplexing and demultiplexing and sensor light multiplexing and demultiplexing, interference between communication light and sensor light, or interference between communication light and backscattered light, can be reduced.

[0212] Implementation method 7.

[0213] In embodiment 7, an optical communication system equipped with a selection device 13 will be described, which connects any one of the P sensor devices 9-p (p=1, ..., P) from 9-1 to 9-P to the optical wavelength division multiplexing device 11.

[0214] Figure 9 This is a structural diagram showing the optical communication system of embodiment 7. Figure 9 Zhongyu Figure 1 , Figure 3 and Figures 5 to 8 The same reference numerals denote the same or equivalent parts, therefore detailed descriptions are omitted.

[0215] Figure 9The optical communication system shown includes: communication devices 1-1~1-M, peer devices 2-1~2-N, first optical fibers 3-1'~3-M', first optical fibers after branching 3-1~3-N, optical amplifiers 4-1~4-N, second optical fibers 5-1'~5-M', second optical fibers after branching 5-1~5-N, optical amplifiers 6-1~6-N, first bypass optical fibers 7-1-1~7-NG, second bypass optical fibers 8-1-1~8-NG, sensor devices 9-1~9-P, optical path switching device 10, optical wavelength division multiplexing and splitting device 11, selection device 13, and optical terminal 14.

[0216] The selection device 13 has multiple input / output ports, and the P sensor devices 9-1 to 9-P and the optical wave combining and splitting device 11 are respectively connected to different input / output ports.

[0217] The selection device 13 connects any one of the P sensor devices 9-p (p=1, ..., P) from 9-1 to 9-P to the optical wave splitting device 11.

[0218] One of the multiple input / output ports of the selection device 13 becomes an optical terminal through the optical terminal 14.

[0219] Optical terminal 14 is a terminal that makes one end of selection device 13 a terminal.

[0220] exist Figure 9 In the optical communication system shown, the selection device 13 is located outside the optical wavelength division multiplexing (WDM) device 11. However, this is only an example; for instance, the selection device 13 could also be located inside the optical wavelength division multiplexing (WDM) device 11.

[0221] Next, regarding Figure 9 The operation of the optical communication system shown will be explained. However, apart from the selection device 13, the operation of the optical communication system is also explained. Figure 6 The optical communication system shown is the same. Therefore, the operation of the selection device 13 will be mainly described here.

[0222] The selection device 13 connects any one of the P sensor devices 9-p (p=1, ..., P) from 9-1 to 9-P to the optical wave splitting device 11.

[0223] When the sensor device 9-p (p=1, ..., P) is connected to the optical wave combiner / splitter 11 via the selection device 13, the sensor light emitted from the sensor device 9-p is output to the optical wave combiner / splitter 11 via the selection device 13. In addition, the backscattered light output from the optical wave combiner / splitter 11 is output to the sensor device 9-p via the selection device 13.

[0224] One of the multiple input / output ports of the selection device 13 becomes an optical terminal via the optical terminal 14. Thus, when sensor light is transmitted from sensor device 9-p, for example, when sensor light is transmitted from peer device 2-n, the sensor light transmitted from peer device 2-n becomes an optical terminal, thereby preventing multiple reflections of the sensor light.

[0225] In Embodiment 7 described above, the optical communication system is configured such that it includes a selection device 13 that connects any one of the P sensor devices 9-1 to 9-P to the optical multiplexing / demultiplexing device 11. Therefore, the optical communication system can detect various changes in the communication optical fiber without laying the sensing optical fiber connecting the communication devices 1-1 to 1-M to the peer devices 2-1 to 2-N.

[0226] Implementation method 8.

[0227] In embodiment 8, an optical communication system is described as follows: as a connection component connected to the first optical fiber 3, the first bypass optical fiber 7-g (g=1, ..., G) is equipped with a wavelength division multiplexing filter 7a or a wavelength division multiplexing coupler 7b; as a connection component connected to the second optical fiber 5, the second bypass optical fiber 8-g is equipped with a wavelength division multiplexing filter 8a or a wavelength division multiplexing coupler 8b.

[0228] Figure 10 This is a structural diagram showing a portion of the optical communication system in Embodiment 8. Figure 10 Zhongyu Figure 1 , Figure 3 and Figures 5 to 9 The same reference numerals denote the same or equivalent parts, therefore detailed descriptions are omitted.

[0229] The first bypass fiber 7-g (g=1, ..., G) is equipped with a wavelength division multiplexing filter 7a or a wavelength division multiplexing coupler 7b as a connection component connected to the first fiber 3.

[0230] The second bypass fiber 8-g has a wavelength division multiplexing filter 8a or a wavelength division multiplexing coupler 8b as a connection component for connection to the second fiber 5.

[0231] exist Figure 10 In the optical communication system shown, wavelength division multiplexing filters 7a and 8a or wavelength division multiplexing couplers 7b and 8b are applied to... Figure 1 The optical communication system shown is just one example. However, wavelength division multiplexing filters 7a and 8a, or wavelength division multiplexing couplers 7b and 8b, can also be applied. Figure 3 and Figures 5 to 9 The optical communication system shown.

[0232] exist Figure 10 In the illustrated optical communication system, the first bypass fiber 7-g, serving as a connection component connected to the first fiber 3, is equipped with a wavelength division multiplexing (WDM) filter 7a or a WDM coupler 7b. Similarly, the second bypass fiber 8-g, serving as a connection component connected to the second fiber 5, is equipped with a WDM filter 8a or a WDM coupler 8b. The WDM filters 7a and 8a, and the WDM couplers 7b and 8b, are all passive components. Therefore, even when monitoring and control communication between devices cannot be established, making it impossible to actively control the connection components connected to the first fiber 3 and the second fiber 5, or when the optical amplifiers 4 and 6 are powered off, the communication fiber can still be sensed.

[0233] Implementation method 9.

[0234] In Embodiment 9, the following optical communication system will be described, wherein the first bypass optical fiber 7-g (g=1, ..., G) is equipped with a bidirectional optical amplifier 7c that does not include an optical isolator, and the second bypass optical fiber 8-g is equipped with a bidirectional optical amplifier 8c that does not include an optical isolator.

[0235] Figure 11 This is a structural diagram showing a part of the optical communication system in Embodiment 9. Figure 11 Zhongyu Figure 1 , Figure 3 and Figures 5 to 10 The same reference numerals denote the same or equivalent parts, therefore detailed descriptions are omitted.

[0236] The optical amplifier 7c is implemented, for example, by a semiconductor optical amplifier (SOA).

[0237] Optical amplifier 7c is inserted into the first bypass fiber 7-g (g=1,…,G).

[0238] The optical amplifier 7c is a bidirectional optical amplifier without an optical isolator, which amplifies both sensor light and backscattered light.

[0239] Optical amplifier 8c is implemented, for example, by SOA.

[0240] Optical amplifier 8c is inserted into the second bypass fiber 8-g (g=1,…,G).

[0241] The optical amplifier 8c is a bidirectional optical amplifier without an optical isolator, which amplifies both sensor light and backscattered light.

[0242] exist Figure 11 In the optical communication system shown, optical amplifier 7c and optical amplifier 8c are respectively used in... Figure 1The optical communication system shown is just one example; optical amplifiers 7c and 8c can also be applied to other systems. Figure 3 or Figures 5 to 10 Any one of the optical communication systems shown in the image.

[0243] exist Figure 11 In the optical communication system shown, since the optical amplifier 7c is inserted into the first bypass optical fiber 7-g, the sensor light and backscattered light transmitted by the first bypass optical fiber 7-g are amplified respectively.

[0244] Since the optical amplifier 7c is a bidirectional optical amplifier, both the sensor light and the backscattered light can pass through the optical amplifier 7c.

[0245] In addition, since the optical amplifier 8c is inserted into the second bypass fiber 8-g, the sensor light and backscattered light transmitted by the second bypass fiber 8-g are amplified respectively.

[0246] Since the optical amplifier 8c is a bidirectional optical amplifier, both the sensor light and the backscattered light can pass through the optical amplifier 8c.

[0247] thus, Figure 11 The optical communication system shown is Figure 1 Compared to the optical communication system shown, it can improve the sensing accuracy of sensor device 9.

[0248] Implementation Method 10.

[0249] In Embodiment 10, the following optical communication system will be described: a first bypass optical fiber 7-g (g=1, ..., G) is equipped with an optical bandpass filter 7d that allows sensor light and backward propagation light to pass through, and a second bypass optical fiber 8-g is equipped with an optical bandpass filter 8d that allows sensor light and backward propagation light to pass through.

[0250] Figure 12 This is a structural diagram showing a portion of the optical communication system in Embodiment 10. Figure 12 Zhongyu Figure 1 , Figure 3 and Figures 5 to 11 The same reference numerals denote the same or equivalent parts, therefore detailed descriptions are omitted.

[0251] Optical bandpass filters 7d are implemented, for example, by dielectric multilayer films or diffraction gratings.

[0252] The optical bandpass filter 7d is inserted into the first bypass fiber 7-g (g=1,…,G).

[0253] The optical bandpass filter 7d allows sensor light and backward propagating light to pass through, while blocking noise and other noise from passing through.

[0254] An optical bandpass filter 8d is implemented, for example, by a dielectric multilayer film or a diffraction grating.

[0255] The optical bandpass filter 8d is inserted into the second bypass fiber 8-g (g=1,…,G).

[0256] The optical bandpass filter 8d allows sensor light and backpropagating light to pass through while blocking noise and other noise.

[0257] exist Figure 12 In the optical communication system shown, optical bandpass filter 7d and optical bandpass filter 8d are respectively applied to Figure 1 The optical communication system shown is just one example; however, the 7d and 8d optical bandpass filters can also be applied to other systems. Figure 3 or Figures 5 to 11 Any of the optical communication systems shown.

[0258] exist Figure 12 In the optical communication system shown, since the optical bandpass filter 7d is inserted into the first bypass optical fiber 7-g, the sensor light and backscattered light transmitted by the first bypass optical fiber 7-g can pass through respectively, while noise and the like are blocked from passing through.

[0259] Furthermore, since the optical bandpass filter 8d is inserted into the second bypass fiber 8-g, the sensor light and backscattered light transmitted by the second bypass fiber 8-g can pass through separately, while noise and other noise can be blocked from passing through.

[0260] thus, Figure 12 The optical communication system shown is Figure 1 Compared to the optical communication system shown, it can improve the sensing accuracy of sensor device 9.

[0261] Implementation Method 11.

[0262] In Embodiment 11, an optical communication system in which the third optical fiber 15 is connected to the optical path switching device 10 will be described.

[0263] Figure 13 This is a structural diagram of the optical communication system in embodiment 11. Figure 13 Zhongyu Figure 1 , Figure 3 and Figures 5 to 12 The same reference numerals denote the same or equivalent parts, therefore detailed descriptions are omitted.

[0264] The third optical fiber 15 is, for example, implemented by a single-core or multi-core wire of a single-mode or multi-mode optical fiber.

[0265] The third optical fiber 15 is a sensor-specific optical fiber connected at one end to the optical path switching device 10.

[0266] exist Figure 13 In the optical communication system shown, the third optical fiber 15 is used Figure 5 The optical communication system shown is just one example; the third fiber 15 can also be applied to... Figure 3 or Figures 6 to 12 Any one of the optical communication systems shown in the image.

[0267] exist Figure 13 In the optical communication system shown, in addition to the first branched optical fibers 3-1 to 3-N and the second branched optical fibers 5-1 to 5-N, the third optical fiber 15 is also connected to the optical path switching device 10. Therefore, it is possible to sense not only the first branched optical fibers 3-1 to 3-N and the second branched optical fibers 5-1 to 5-N, but also the third optical fiber 15.

[0268] Figure 14 This is a structural diagram showing another optical communication system in embodiment 11.

[0269] like Figure 14 As shown, the third optical fiber 15 can also be wound around the cable to realize a CT (Current Transformer) for measuring the current flowing through the cable.

[0270] In this case, it is possible not only to sense the first fiber 3-1 to 3-N after branching and the second fiber 5-1 to 5-N after branching, but also to sense the third fiber 15.

[0271] Implementation method 12.

[0272] In embodiments 1 to 11, the optical communication system includes: a plurality of first bypass optical fibers 7-g (g=1, ..., G) and 7-ng, which bypass optical amplifiers 4 and 4-n inserted into first optical fibers 3 and 3-n (n=1, ..., N); and a plurality of second bypass optical fibers 8-g and 8-ng, which bypass optical amplifiers 6 and 6-n inserted into second optical fibers 5 and 5-n.

[0273] In embodiment 12, the following optical communication system will be described. In order to connect multiple optical amplifiers 4 (or optical amplifiers 4-n) in parallel, one or more communication optical bypass optical fibers 21 are laid for the first optical fiber 3 (or the first optical fiber 3-n after branching). In addition, in order to connect multiple optical amplifiers 6 (or optical amplifiers 6-n) in parallel, one or more communication optical bypass optical fibers 22 are laid for the second optical fiber 5 (or the second optical fiber 5-n after branching).

[0274] Figure 15 This is a structural diagram of the optical communication system in embodiment 12. Figure 15 Zhongyu Figure 1 , Figure 3 and Figures 5 to 14 The same reference numerals denote the same or equivalent parts, therefore detailed descriptions are omitted.

[0275] exist Figure 15 In the optical communication system shown, a bandpass filter 3a is inserted in series with optical amplifier 4 (or optical amplifier 4-n), and a bandpass filter 5a is inserted in series with optical amplifier 6 (or optical amplifier 6-n).

[0276] One or more optical fiber 21 used for communication optical bypass is inserted with bandpass filters 23 that have different passing bands. The passing band of each bandpass filter 23 is different from that of the bandpass filter 3a.

[0277] In addition, one or more optical fibers 22 for communication optical bypass are respectively inserted with bandpass filters 24 with different passing bands, and the passing band of each bandpass filter 24 is different from the passing band of bandpass filter 5a.

[0278] Thus, communication devices 1 and 1-m (m=1, ..., M) and the counterpart devices 2 and 2-n can transmit and receive multiple communication lights with different wavelengths.

[0279] Furthermore, this disclosure allows for free combination of various embodiments, modification of any constituent elements of each embodiment, or omission of any constituent elements in each embodiment.

[0280] Industrial availability

[0281] This disclosure applies to optical communication systems.

[0282] Explanation of reference numerals in the attached figures

[0283] 1: Communication device; 2, 2-1~2-N: Remote device; 3, 3-1'~3-M': First optical fiber; 3-1~3-N: First optical fiber after branching; 3a: Bandpass filter; 4, 4-1~4-N: Optical amplifier; 5, 5-1'~5-M': Second optical fiber; 5-1~5-N: Second optical fiber after branching; 5a: Bandpass filter; 6, 6-1~6-N: Optical amplifier; 7-1~7-G, 7-1-1~7-NG: First bypass optical fiber; 7a: Wavelength division multiplexing filter; 7b: Wavelength division multiplexing coupler; 7c: Optical amplifier; 7d: Optical bandpass filter; 8-1~8-G, 8-1-1~8-NG: Second bypass fiber; 8a: Wavelength division multiplexing filter; 8b: Wavelength division multiplexing coupler; 8c: Optical amplifier; 8d: Optical bandpass filter; 9, 9-1~9-P: Sensor device; 10: Optical path switching device; 11: Optical wavelength division multiplexing device; 11a: First optical wavelength division multiplexer; 11b: Second optical wavelength division multiplexer; 12: Optical wavelength division multiplexing device; 13: Selection device; 14: Optical terminal; 15: Third fiber; 21, 22: Communication optical bypass fiber; 23, 24: Bandpass filter.

Claims

1. An optical communication system, characterized in that, have: The first optical fiber enables the communication light transmitted from the communication device to be transmitted to the other end device. A second optical fiber, which transmits communication light from the peer device to the communication device; Multiple first bypass optical fibers bypass optical amplifiers inserted into the first optical fibers; Multiple second bypass optical fibers bypass the optical amplifier inserted into the second optical fiber; as well as A sensor device that sends sensor light into either the first optical fiber or the second optical fiber and receives backscattered light returning from either the first optical fiber or the second optical fiber.

2. The optical communication system according to claim 1, characterized in that, There are N counterpart devices, where N is an integer greater than or equal to 2. The optical communication system includes: An optical path switching device branches the first optical fiber and the second optical fiber into N branches, and connects them to each peer device via the branched first optical fiber and the branched second optical fiber, respectively. As the first bypass fiber, the multiple first bypass fibers bypass the optical amplifiers inserted into the first fiber after each branch. as well as As a plurality of second bypass optical fibers, they bypass the optical amplifiers of the second optical fibers inserted into each branch.

3. The optical communication system according to claim 2, characterized in that, There are M communication devices, where M is an integer greater than or equal to 2. The optical communication system includes an optical wavelength division multiplexing (OSM) device. The OSM device combines communication optical signals sent from any one or more of the M communication devices and outputs the combined communication optical signal to the optical path switching device. The OSM device then divides the communication optical signal output from the optical path switching device and outputs each divided communication optical signal to any one of the M communication devices.

4. The optical communication system according to claim 3, characterized in that, The optical wave combining and splitting device sends the sensor light sent from the sensor device to either the first or second branched optical fiber via the optical path switching device, and outputs the backscattered light returning from either the first or second branched optical fiber to the sensor device.

5. The optical communication system according to claim 3, characterized in that, The sensor device comprises P units, where P is an integer greater than or equal to 2. The optical wave combining and splitting device outputs the sensor light sent from the P sensor devices to the optical path switching device, and outputs the backscattered light output from the optical path switching device to the sensor device that is the source of the sensor light.

6. The optical communication system according to claim 3, characterized in that, The optical wave splitter outputs backscattered light within the passing band from the backscattered light output from the optical path switching device to the sensor device, and blocks backscattered light outside the passing band.

7. The optical communication system according to claim 5, characterized in that, The optical wavelength division and splitting device includes: The first optical multiplexer and demultiplexer combines communication optical signals sent from any one or more of the M communication devices and outputs the combined communication optical signal to the optical path switching device. It then demultiplexes the communication optical signal output from the optical path switching device and outputs each demultiplexed communication optical signal to any one of the M communication devices. as well as The second optical wave combiner / splitter outputs sensor light transmitted from any one or more of the P sensor devices to the optical path switching device, and outputs backscattered light from the optical path switching device to the sensor device that is the source of the sensor light.

8. The optical communication system according to claim 5, characterized in that, It has a selection device that connects any one of the P sensor devices to the optical wave splitter.

9. The optical communication system according to claim 8, characterized in that, One end of the selection device becomes an optical terminal.

10. The optical communication system according to claim 1, characterized in that, The first optical fiber and the second optical fiber are either single-core or multi-core wires of single-mode optical fiber and multi-mode optical fiber, respectively.

11. The optical communication system according to claim 1, characterized in that, The first bypass optical fiber has a wavelength division multiplexing filter or wavelength division multiplexing coupler as a connection component relative to the first optical fiber. The second bypass fiber has a wavelength division multiplexing filter or wavelength division multiplexing coupler as a connection component relative to the second fiber.

12. The optical communication system according to claim 1, characterized in that, The first bypass optical fiber and the second bypass optical fiber each have a bidirectional optical amplifier that does not include an optical isolator.

13. The optical communication system according to claim 1, characterized in that, The first bypass optical fiber and the second bypass optical fiber are respectively equipped with optical bandpass filters that allow the sensor light and the backward propagating light to pass through.

14. The optical communication system according to claim 2, characterized in that, In addition to the first optical fiber and the second optical fiber after branching, the optical path switching device is also connected to a third optical fiber.

15. The optical communication system according to claim 1, characterized in that, Multiple optical amplifiers are connected in parallel to the first optical fiber, and multiple optical amplifiers are connected in parallel to the second optical fiber.

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