JP7653689B2 - Four-way optical switch and optical fiber network - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act Announced at the 2021 Society Conference of the Institute of Electronics, Information and Communication Engineers held on August 31, 2021

This disclosure relates to a four-way optical switch that switches optical paths in a loop-type optical fiber network and an optical fiber network that uses the same.

Until now, optical fiber networks in access systems, such as FTTH (Fiber To The Home), have provided communication services by laying optical fiber in a star shape from a communication center (for example, see Non-Patent Document 1).

Masahito Arii, "Trends in Optical Access Network Technology Promoting FTTH," NTT Technical Journal, February 2010. R. Helkey et al. , “Remotely Powered Optical Switch for Remote Subscriber Aggregation and OTDR Measurement in PON,” 33rd European Conference and Exhibition of Optical Communication, Berlin, Germany, 2007, pp. 1-2, doi: 10.1049/ic:20070283.

However, the optical fiber network proposed in Non-Patent Document 1 does not have the flexibility to deal with fluctuations in demand for optical fiber, and it is difficult to install optical fiber in another location once it has been installed.

In addition, if the optical fiber network was not redundant and an optical fiber was cut, the only way to restore service was to directly repair the broken optical fiber, which could result in a significant outage of service.

Conventionally, a device that converts optical energy transmitted through optical fiber into electrical power and switches optical fiber paths has been proposed as a technology for switching optical fiber paths without using commercial power (see, for example, Non-Patent Document 2). This is a device that converts optical energy transmitted through optical fiber into electrical power and switches optical fiber paths, but the optical power that must be supplied is very large, at around 1 W, and there is a problem that it is difficult to put into practical use from a safety standpoint.

Therefore, in order to solve the above problems, the present disclosure aims to provide an optical fiber network that is flexible in response to demand for optical fiber and allows for rapid recovery in the event of an optical fiber break, and a four-way optical switch with a simple configuration for use therein.

To solve the above problems, this disclosure proposes an optical fiber network with a topology in which two sets of optical fibers in a loop are connected and each optical fiber is switched. It also proposes a four-way optical switch that can be applied to the connection of two sets of optical fibers in a loop.

Specifically, the present disclosure provides:
a first port, a second port, a third port, and a fourth port;
a first connection state in which the first port and the second port are internally connected and the third port and the fourth port are internally connected;
a second connection state in which the first port and the third port are internally connected and the second port and the fourth port are internally connected;
a third connection state in which the first port and the fourth port are internally connected and the second port and the third port are internally connected;
This is a four-way optical switch that can switch between

The present disclosure also provides
a parallel connection state in which the first terminal and the second terminal are internally connected to each other, and the third terminal and the fourth terminal are internally connected to each other;
a cross-connection state in which the first terminal and the fourth terminal, and the second terminal and the third terminal are internally connected, respectively;
a first and a second set of switchable 2×2 optical switches;
the third terminal of the first 2×2 optical switch and the first terminal of the second 2×2 optical switch are connected, and the fourth terminal of the first 2×2 optical switch and the third terminal of the second 2×2 optical switch are connected,
the first terminal of the first 2×2 optical switch is internally connected to the first port;
the second terminal of the first 2×2 optical switch is internally connected to the second port;
the second terminal of the second 2×2 optical switch is internally connected to the third port;
The fourth terminal of the second 2×2 optical switch is internally connected to the fourth port.

The present disclosure also provides
a parallel connection state in which the first terminal and the second terminal are internally connected to each other, and the third terminal and the fourth terminal are internally connected to each other;
a cross-connection state in which the first terminal and the fourth terminal, and the second terminal and the third terminal are internally connected, respectively;
a first and a second set of switchable 2×2 optical switches;
the first terminal of the first 2×2 optical switch and the first terminal of the second 2×2 optical switch are connected, the fourth terminal of the first 2×2 optical switch and the third terminal of the second 2×2 optical switch are connected,
the second terminal of the second 2×2 optical switch is internally connected to the first port;
the second terminal of the first 2×2 optical switch is internally connected to the second port;
the third terminal of the first 2×2 optical switch is internally connected to the third port;
The fourth terminal of the second 2×2 optical switch is internally connected to the fourth port.

The present disclosure also provides
an optical switch control circuit that controls switching between the first connection state, the second connection state, and the third connection state;
The present invention is characterized by further comprising:

Specifically, the present disclosure provides:
Any one of the four-way optical switches described above;
a first optical fiber connected to the first port of the four-way optical switch;
a second optical fiber connected to the second port of the four-way optical switch;
It is an optical fiber network that is equipped with

The present disclosure also provides
a fifth optical fiber connected to the optical switch control circuit of the four-way optical switch;
a center-side control device that optically supplies power to the optical switch control circuit of the four-way optical switch via the fifth optical fiber and instructs switching control of the first connection state, the second connection state, or the third connection state;
Further equipped with
The optical switch control circuit is characterized in that it operates with optical power supply from the center side control device and controls switching between the first connection state, the second connection state, and the third connection state in response to instructions from the center side control device.

The present disclosure also provides
a third optical fiber connected to the third port of the four-way optical switch;
a fourth optical fiber connected to the fourth port of the four-way optical switch;
The present invention is characterized by further comprising:

The above disclosed inventions can be combined as much as possible.

In this way, the present disclosure can provide an optical fiber network that is flexible in response to optical fiber demand and allows for rapid recovery in the event of an optical fiber break, as well as a four-way optical switch for use therein.

1A and 1B are diagrams illustrating a configuration of a four-way optical switch according to the present disclosure. 1A and 1B are diagrams illustrating a configuration of a four-way optical switch according to the present disclosure. 1A and 1B are diagrams illustrating a configuration of a four-way optical switch according to the present disclosure. 1A and 1B are diagrams illustrating a configuration of a four-way optical switch according to the present disclosure. 1A and 1B are diagrams illustrating a configuration of a four-way optical switch according to the present disclosure. 1A and 1B are diagrams illustrating a configuration of a four-way optical switch according to the present disclosure. 1A and 1B are diagrams illustrating a configuration of a four-way optical switch according to the present disclosure. 1A and 1B are diagrams illustrating a configuration of a four-way optical switch according to the present disclosure. FIG. 2 is a diagram illustrating the configuration of an optical fiber network according to the present disclosure. FIG. 2 is a diagram illustrating the configuration of an optical fiber network according to the present disclosure. FIG. 2 is a diagram illustrating the configuration of an optical fiber network according to the present disclosure.

The following describes in detail the embodiments of the present disclosure with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below. These implementation examples are merely illustrative, and the present disclosure can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. Note that components with the same reference numerals in this specification and drawings are mutually identical.

(Embodiment 1)
The configuration of a four-way optical switch of this embodiment is shown in Fig. 1. A four-way optical switch 10 of this embodiment has a first port P1, a second port P2, a third port P3, and a fourth port P4.

The four-way optical switch 10 can be switched between a first connection state (FIG. 1(a)), a second connection state (FIG. 1(b)), and a third connection state (FIG. 1(c)). In the first connection state, the first port P1 and the second port P2 are internally connected, and the third port P3 and the fourth port P4 are internally connected. In the second connection state, the first port P1 and the third port P3 are internally connected, and the second port P2 and the fourth port P4 are internally connected. In the third connection state, the first port P1 and the fourth port P4 are internally connected, and the second port P2 and the third port P3 are internally connected.

Therefore, a four-way optical switch with a simple configuration can be realized. Furthermore, by making it possible to switch between these three connection states, it can be used in optical fiber networks that are flexible in response to optical fiber demand and can quickly recover from optical fiber breaks.

(Embodiment 2)
The configuration of the four-way optical switch of this embodiment is shown in Figures 2, 3, and 4. The four-way optical switch 10 of this embodiment includes a first 2x2 optical switch 11 and a second 2x2 optical switch 12. The first 2x2 optical switch 11 and the second 2x2 optical switch 12 each have a first terminal T1, a second terminal T2, a third terminal T3, and a fourth terminal T4.

The first 2x2 optical switch 11 and the second 2x2 optical switch 12 can each be switched between a parallel connection state and a cross connection state. In the parallel connection state, the first terminal T1 and the second terminal T2 are internally connected, and the third terminal T3 and the fourth terminal T4 are internally connected. In the cross connection state, the first terminal T1 and the fourth terminal T4 are internally connected, and the second terminal T2 and the third terminal T3 are internally connected.

The third terminal T3 of the first 2x2 optical switch 11 is connected to the first terminal T1 of the second 2x2 optical switch 12, and the fourth terminal T4 of the first 2x2 optical switch 11 is connected to the third terminal T3 of the second 2x2 optical switch 12.

In the four-way optical switch 10, the first terminal T1 of the first 2×2 optical switch 11 may be internally connected to the first port P1, or the first terminal T1 of the first 2×2 optical switch 11 may function as the first port P1. The second terminal T2 of the first 2×2 optical switch 11 may be internally connected to the second port P2, or the second terminal T2 of the first 2×2 optical switch 11 may function as the second port P2. The second terminal T2 of the second 2×2 optical switch 12 may be internally connected to the third port P3, or the second terminal T2 of the second 2×2 optical switch 12 may function as the third port P3. The fourth terminal T4 of the second 2×2 optical switch 12 may be internally connected to the fourth port P4, or the fourth terminal T4 of the second 2×2 optical switch 12 may function as the fourth port P4.

Figure 2 shows the first connection state of the four-way optical switch. The first connection state can be either the connection configuration shown in Figure 2(a) or Figure 2(b). In Figure 2(a), the first 2x2 optical switch 11 is in a parallel connection state, and the second 2x2 optical switch 12 is also in a parallel connection state. In Figure 2(b), the first 2x2 optical switch 11 is in a parallel connection state, and the second 2x2 optical switch 12 is in a cross connection state. According to this connection configuration, the first port P1 and the second port P2 are internally connected, and the third port P3 and the fourth port P4 are internally connected. That is, the first connection state is realized.

Figure 3 shows the second connection state of the four-way optical switch. In Figure 3, the first 2x2 optical switch 11 is in a cross-connected state, and the second 2x2 optical switch 12 is also in a cross-connected state. According to this connection configuration, the first port P1 and the third port P3 are internally connected, and the second port P2 and the fourth port P4 are internally connected. In other words, the second connection state is realized.

Figure 4 realizes the third connection state of the four-way optical switch. In Figure 4, the first 2x2 optical switch 11 is in a cross-connection state, and the second 2x2 optical switch 12 is in a parallel connection state. According to this connection configuration, the first port P1 and the fourth port P4 are internally connected, and the second port P2 and the third port P3 are internally connected. In other words, the third connection state is realized.

The first 2x2 optical switch 11 and the second 2x2 optical switch 12 should desirably operate at low voltage (3-5V) with extremely low power consumption of several hundred μJ or less. For example, it is possible to use a self-holding MEMS optical switch that requires little drive power and is generally available. If it is a self-holding type, it will lead to power savings.

Therefore, by using two 2x2 optical switches, a four-way optical switch with a simple configuration can be realized. Furthermore, if it is possible to switch between these three connection states, it can be used in the optical fiber network described below.

(Embodiment 3)
The configuration of the four-way optical switch of this embodiment is shown in Figures 5, 6 and 7. The four-way optical switch 10 of this embodiment includes a first 2x2 optical switch 11 and a second 2x2 optical switch 12. The first 2x2 optical switch 11 and the second 2x2 optical switch 12 each have a first terminal T1, a second terminal T2, a third terminal T3 and a fourth terminal T4.

The first 2x2 optical switch 11 and the second 2x2 optical switch 12 can each be switched between a parallel connection state and a cross connection state. In the parallel connection state, the first terminal T1 and the second terminal T2 are internally connected, and the third terminal T3 and the fourth terminal T4 are internally connected. In the cross connection state, the first terminal T1 and the fourth terminal T4 are internally connected, and the second terminal T2 and the third terminal T3 are internally connected.

The first terminal T1 of the first 2x2 optical switch 11 is connected to the first terminal T1 of the second 2x2 optical switch 12, and the fourth terminal T4 of the first 2x2 optical switch 11 is connected to the third terminal T3 of the second 2x2 optical switch 12.

In the four-way optical switch 10, the second terminal T2 of the second 2×2 optical switch 12 may be internally connected to the first port P1, or the second terminal T2 of the second 2×2 optical switch 12 may function as the first port P1. The second terminal T2 of the first 2×2 optical switch 11 may be internally connected to the second port P2, or the second terminal T2 of the first 2×2 optical switch 11 may function as the second port P2. The third terminal T3 of the first 2×2 optical switch 11 may be internally connected to the third port P3, or the third terminal T3 of the first 2×2 optical switch 11 may function as the third port P3. The fourth terminal T4 of the second 2×2 optical switch 12 may be internally connected to the fourth port P4, or the fourth terminal T4 of the second 2×2 optical switch 12 may function as the fourth port P4.

Figure 5 shows the first connection state of the four-way optical switch. In Figure 5, the first 2x2 optical switch 11 is in a parallel connection state, and the second 2x2 optical switch 12 is also in a parallel connection state. According to this connection configuration, the first port P1 and the second port P2 are internally connected, and the third port P3 and the fourth port P4 are internally connected. In other words, the first connection state is realized.

Figure 6 shows the second connection state of the four-way optical switch. In Figure 6, the first 2x2 optical switch 11 is in a parallel connection state, and the second 2x2 optical switch 12 is in a cross connection state. According to this connection configuration, the first port P1 and the third port P3 are internally connected, and the second port P2 and the fourth port P4 are internally connected. In other words, the second connection state is realized.

Figure 7 realizes the third connection state of the four-way optical switch. In Figure 7(a), the first 2x2 optical switch 11 is in a cross-connection state, and the second 2x2 optical switch 12 is in a parallel connection state. In Figure 7(b), the first 2x2 optical switch 11 is in a cross-connection state, and the second 2x2 optical switch 12 is also in a cross-connection state. According to this connection configuration, the first port P1 and the fourth port P4 are internally connected, and the second port P2 and the third port P3 are internally connected. That is, the third connection state is realized.

The first 2x2 optical switch 11 and the second 2x2 optical switch 12 should desirably operate at low voltage (3-5V) with extremely low power consumption of several hundred μJ or less. For example, it is possible to use a self-holding MEMS optical switch that requires little drive power and is generally available.

Therefore, by using two 2x2 optical switches, a four-way optical switch with a simple configuration can be realized. Furthermore, if it is possible to switch between these three connection states, it can be used in the optical fiber network described below.

(Embodiment 4)
The configuration of the four-way optical switch of this embodiment is shown in Fig. 8. The four-way optical switch 10 of this embodiment includes a first 2x2 optical switch 11, a second 2x2 optical switch 12, and an optical switch control circuit. The terminal connections, port connections, and parallel connection state or cross connection state of the first 2x2 optical switch 11 and the second 2x2 optical switch 12 are as described in the second or third embodiment.

The optical switch control circuit 13 has a microprocessor 38 and controls the first 2×2 optical switch 11 and the second 2×2 optical switch 12 to switch between the first connection state, the second connection state, and the third connection state.

The optical switch control circuit 13 may operate the microprocessor 38 in response to an instruction from outside the four-way optical switch 10. The optical switch control circuit 13 further includes an optical branching unit 32, a photoelectric conversion element 33, and a reflective optical switch 37. The microprocessor 38 has a downstream frame analysis function 40, an upstream signal generation function 41, and a switching operation control function 42.

Downstream light 30 is received via the fifth optical fiber 28. The optical branching unit 32 branches the downstream light 30 to the photoelectric conversion element 33 and the reflective optical switch 37. It is preferable that the optical branching unit 32 branches a larger proportion of the downstream light 30 to the photoelectric conversion element 33 than to the reflective optical switch 37. The optical branching unit 32 is, for example, an optical coupler. A portion of the branched downstream light 30 is converted to an electrical signal by the photoelectric conversion element 33. The photoelectric conversion element 33 can be made of indium gallium arsenide, which is suitable for the long wavelength band of 1300 to 1600 nm for communications, and has an open circuit voltage of 5 V or less and a conversion efficiency of about 30%.

The downstream frame analysis function 40 of the microprocessor 38 analyzes the contents of the downstream signal, and the switching operation control function 42 controls the first 2×2 optical switch 11 and the second 2×2 optical switch 12. To respond to an external instruction, a portion of the downstream light 30 branched by the optical branching unit 32 is reflected by the reflective optical switch 37 to generate an upstream signal light 31. The reflective optical switch 37 is controlled by the upstream signal generation function 41. The optical branching unit 32 multiplexes the upstream signal light 31 into the fifth optical fiber 28.

To generate the upstream signal light 31 with the reflective light switch 37, a part of the downstream light 30 may be unmodulated light, and the reflective light switch 37 may modulate the light during the unmodulated period. In this case, the modulation format of the downstream light 30 and the upstream signal light 31 does not matter. The reflective light switch 37 may modulate the downstream light 30 at a modulation speed sufficiently slower than the modulation speed of the downstream light 30. In this case, the modulation format of the downstream light 30 may be pulse phase modulation or pulse frequency modulation that keeps the average light intensity constant, or pulse intensity modulation or pulse position modulation that keeps the average light intensity constant within a certain period. The modulation format of the upstream signal light 31 may be any modulation format, including pulse intensity modulation. In FIG. 8, the upstream signal light 31 is generated using reflection, but if there is sufficient power, the upstream signal light 31 may be generated by modulating a light-emitting element.

Therefore, by using two 2x2 optical switches, a four-way optical switch with low power consumption can be realized. Furthermore, if it is possible to switch between these three connection states, it can be used in the optical fiber network described below.

(Embodiment 5)
The configuration of the optical fiber network of this embodiment is shown in Fig. 9. The optical fiber network of this embodiment includes a four-way optical switch 10, a first optical fiber 24 connected to a first port P1 of the four-way optical switch 10, and a second optical fiber 25 connected to a second port P2 of the four-way optical switch 10. The optical fiber network of this embodiment may further include a center-side controller 14, and a fifth optical fiber 28 connecting the optical switch control circuit 13 of the four-way optical switch 10 and the center-side controller 14.

The center-side controller 14 in this embodiment optically supplies power to the optical switch control circuit 13 of the four-way optical switch 10 via the fifth optical fiber 28. A long wavelength band of 1300 nm to 1600 nm is suitable for the wavelength of the laser used for optical power supply. In addition, the center-side controller 14 instructs the optical switch control circuit 13 of the four-way optical switch 10 to control switching between the first connection state, the second connection state, and the third connection state via the fifth optical fiber 28.

The configuration of the optical switch control circuit 13 of this embodiment is shown in FIG. 10. The four-way optical switch 10 of this embodiment includes a first 2×2 optical switch 11, a second 2×2 optical switch 12, and an optical switch control circuit 13. The terminal connections, port connections, and parallel connection state or cross connection state of the first 2×2 optical switch 11 and the second 2×2 optical switch 12 are as described in the second or third embodiment. The optical switch control circuit 13 of this embodiment includes an optical branching unit 32, a photoelectric conversion element 33, a secondary battery 34, a microprocessor 38, and a reflective optical switch 37. The microdevice 8 has a downstream frame analysis function 40, an upstream signal generation function 41, a switching operation control function 42, and a power monitoring function 43.

The optical switch control circuit 13 of this embodiment is configured by adding a secondary battery 34 and a power monitoring function 43 to the optical switch control circuit 13 of embodiment 4. The secondary battery 34 and the power monitoring function 43 will be described. The downstream light 30 is converted into electricity by the photoelectric conversion element 33, and the DC component is stored in the secondary battery 34. The secondary battery 34 supplies driving power 35 for the active elements in the four-way optical switch 10. An electric double layer capacitor or the like may be used as the secondary battery 34. The supply voltage from the secondary battery 34 to the four-way optical switch 10 is adjusted appropriately by a DC/DC converter.

The power monitoring function 43 grasps the amount of stored energy in the secondary battery 34 via a voltage monitor or the like, and judges whether or not to switch the first 2×2 optical switch 11 and the second 2×2 optical switch 12 based on a set threshold. If the amount of stored energy is lower than the threshold, the switching of the first 2×2 optical switch 11 and the second 2×2 optical switch 12 is postponed or canceled, and if the amount of stored energy is higher than the threshold, the switching of the first 2×2 optical switch 11 and the second 2×2 optical switch 12 is performed.

As shown in FIG. 11, the optical fiber network of this embodiment may further include a third optical fiber 26 connected to the third port P3 of the four-way optical switch 10 and a fourth optical fiber 27 connected to the fourth port P4 of the four-way optical switch 10. A set of the first optical fiber 24 and the second optical fiber 25 in a loop configuration and a set of the third optical fiber 26 and the fourth optical fiber 27 in a loop configuration are connected together, and the two sets of optical fibers in a loop configuration are each switched by the four-way optical switch 10.

The system may further include a network device 20 connected to the first optical fiber 24 and the second optical fiber 25. The system may further include a network terminal 21 connected to the third optical fiber 26 and the fourth optical fiber 27.

When the center-side control device 14 instructs the optical switch control circuit 13 of the four-way optical switch 10 to switch the four-way optical switch 10 to the first connection state, the first optical fiber 24 and the second optical fiber 25 are connected, and light passes through the four-way optical switch 10. This is a form used when another four-way optical switch is placed midway between the first optical fiber 24 and/or the second optical fiber 25. It can flexibly respond to optical fiber demand.

When the center-side control device 14 instructs the optical switch control circuit 13 of the four-way optical switch 10 to switch the four-way optical switch 10 to the second connection state, the network device 20 and the network terminal 21 are connected via the first optical fiber 24 and the third optical fiber 26, or via the second optical fiber 25 and the fourth optical fiber 27, ensuring a redundant path. The existence of a redundant path allows for rapid recovery in the event of an optical fiber break.

When the center-side control device 14 instructs the optical switch control circuit 13 of the four-way optical switch 10 to switch the four-way optical switch 10 to the third connection state, the network device 20 and the network terminal 21 are connected via the first optical fiber 24 and the fourth optical fiber 27, or via the second optical fiber 25 and the third optical fiber 26, so that a redundant path can be secured. A redundant path allows for rapid recovery in the event of an optical fiber break. By switching between the second connection state and the third connection state, a redundant path can be secured.

Therefore, between the network device 20 and the network terminal 21, two optical fiber routes can be switched for each connection, making it possible to create an optical fiber network with redundant paths.

As described above, by switching the four-way optical switch 10 between the first connection state, the second connection state, and the third connection state, it is possible to configure an optical fiber network that is flexible in response to optical fiber demand and allows for rapid recovery in the event of an optical fiber break.

10 Four-way optical switch 11 First 2×2 optical switch 12 Second 2×2 optical switch 13 Optical switch control circuit 14 Center side control device 20 Network device 21 Network terminal 24 First optical fiber 25 Second optical fiber 26 Third optical fiber 27 Fourth optical fiber 28 Fifth optical fiber 30 Downstream light 31 Upstream signal light 32 Optical branching section 33 Photoelectric conversion element 34 Secondary battery 35 Driving power of active element 37 Reflective optical switch 38 Microprocessor 40 Downstream frame analysis function 41 Upstream signal generation function 42 Switching operation control function 43 Power monitoring function

Claims (3)

A four-way optical switch;
a first optical fiber connected to a first port of the four-way optical switch;
a second optical fiber connected to a second port of the four-way optical switch;
a third optical fiber connected to a third port of the four-way optical switch;
a fourth optical fiber connected to a fourth port of the four-way optical switch;
an optical switch control circuit;
1. An optical fiber network comprising:
The four-way optical switch is controlled by the optical switch control circuit.
a first connection state in which the first port and the second port are internally connected and the third port and the fourth port are internally connected;
a second connection state in which the first port and the third port are internally connected and the second port and the fourth port are internally connected;
a third connection state in which the first port and the fourth port are internally connected and the second port and the third port are internally connected;
is switchable,
The four-way optical switch comprises:
a parallel connection state in which the first terminal and the second terminal are internally connected to each other, and the third terminal and the fourth terminal are internally connected to each other;
a cross-connection state in which the first terminal and the fourth terminal, and the second terminal and the third terminal are internally connected, respectively;
a first 2×2 optical switch and a second 2×2 optical switch,
the third terminal of the first 2×2 optical switch and the first terminal of the second 2×2 optical switch are connected, and the fourth terminal of the first 2×2 optical switch and the third terminal of the second 2×2 optical switch are connected,
the first terminal of the first 2×2 optical switch is internally connected to the first port;
the second terminal of the first 2×2 optical switch is internally connected to the second port;
the second terminal of the second 2×2 optical switch is internally connected to the third port;
the fourth terminal of the second 2×2 optical switch is internally connected to the fourth port;
A set of the first optical fiber and the second optical fiber in a loop configuration on the network device side and a set of the third optical fiber and the fourth optical fiber in a loop configuration on the network terminal side are connected and connected to each other, and two sets of the optical fibers in the loop configuration can be switched;
The optical switch control circuit includes:
instructing the four-way optical switch to be in the first connection state, and causing light of each of the two sets of optical fibers in the loop form to pass through the four-way optical switch;
instructing the four-way optical switch to be in the second connection state, and connecting the network device and the network terminal via the first optical fiber and the third optical fiber, or connecting the network device and the network terminal via the second optical fiber and the fourth optical fiber, to ensure a redundant path; or
instructing the four-way optical switch to be in the third connection state, and connecting the network device and the network terminal via the first optical fiber and the fourth optical fiber, or via the second optical fiber and the third optical fiber, to secure a redundant path.
A fiber optic network characterized by: A four-way optical switch;
a first optical fiber connected to a first port of the four-way optical switch;
a second optical fiber connected to a second port of the four-way optical switch;
a third optical fiber connected to a third port of the four-way optical switch;
a fourth optical fiber connected to a fourth port of the four-way optical switch;
an optical switch control circuit;
1. An optical fiber network comprising:
The four-way optical switch is controlled by the optical switch control circuit.
a first connection state in which the first port and the second port are internally connected and the third port and the fourth port are internally connected;
a second connection state in which the first port and the third port are internally connected and the second port and the fourth port are internally connected;
a third connection state in which the first port and the fourth port are internally connected and the second port and the third port are internally connected;
is switchable,
The four-way optical switch comprises:
a parallel connection state in which the first terminal and the second terminal are internally connected to each other, and the third terminal and the fourth terminal are internally connected to each other;
a cross-connection state in which the first terminal and the fourth terminal, and the second terminal and the third terminal are internally connected, respectively;
a first 2×2 optical switch and a second 2×2 optical switch,
the first terminal of the first 2×2 optical switch and the first terminal of the second 2×2 optical switch are connected, the fourth terminal of the first 2×2 optical switch and the third terminal of the second 2×2 optical switch are connected,
the second terminal of the second 2×2 optical switch is internally connected to the first port;
the second terminal of the first 2×2 optical switch is internally connected to the second port;
the third terminal of the first 2×2 optical switch is internally connected to the third port;
the fourth terminal of the second 2×2 optical switch is internally connected to the fourth port;
A set of the first optical fiber and the second optical fiber in a loop configuration on the network device side and a set of the third optical fiber and the fourth optical fiber in a loop configuration on the network terminal side are connected and connected to each other, and two sets of the optical fibers in the loop configuration can be switched;
The optical switch control circuit includes:
instructing the four-way optical switch to be in the first connection state, and causing light of each of the two sets of optical fibers in the loop form to pass through the four-way optical switch;
instructing the four-way optical switch to be in the second connection state, and connecting the network device and the network terminal via the first optical fiber and the third optical fiber, or connecting the network device and the network terminal via the second optical fiber and the fourth optical fiber, to ensure a redundant path; or
instructing the four-way optical switch to be in the third connection state, and connecting the network device and the network terminal via the first optical fiber and the fourth optical fiber, or via the second optical fiber and the third optical fiber, to secure a redundant path.
A fiber optic network characterized by: a fifth optical fiber connected to the optical switch control circuit of the four-way optical switch;
a center-side control device that optically supplies power to the optical switch control circuit of the four-way optical switch via the fifth optical fiber and instructs switching control of the first connection state, the second connection state, or the third connection state;
Further equipped with
The optical fiber network according to claim 1 or 2, characterized in that the optical switch control circuit operates with optical power supply from the center side control device and controls switching between the first connection state, the second connection state, and the third connection state in response to instructions from the center side control device.

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