JP7637388B2 - Optical fiber path switching device and method - Google Patents

Description

This disclosure relates to technology that supplies power through optical power supply and switches optical fiber paths in environments where power sources are difficult to obtain.

As an optical fiber path switching technology, a device has been proposed for use in communication buildings, user facilities, and other locations where commercial power is available. This device monitors the communication optical power of two optical fiber paths, one for use in operation and one for emergency use, and switches the optical fiber path to a system that is not causing any problems when an abnormality occurs, such as a drop in optical power. (See, for example, Non-Patent Document 1.)

As a technology for switching optical fiber paths without using commercial power, a device that converts the optical energy of optical fibers into electricity and switches optical fiber paths has been proposed (see, for example, Non-Patent Document 2). However, in Non-Patent Document 2, the optical power that needs to be supplied is very large, at about 1 W, and there is a problem that it is difficult to put into practical use from a safety standpoint.

DENSO CORPORATION: Automatic optical transmission line switching device, https://www.kk-denso.co.jp/products/automatic-light.php, (Accessed 2020.12.16) 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.

The purpose of this disclosure is to achieve optical path switching by supplying weak optical power.

This disclosure realizes a configuration that stores weak optical power over time and can extract large power when operating the optical path changeover switch. The control device monitors the power storage status and confirms whether there is sufficient power, and then operates the optical path changeover switch, thereby realizing optical path changeover by supplying weak optical power.

Specifically, the optical fiber route switching device of the present disclosure comprises:
An optical fiber route switching device is used in an optical transmission path in which a station side transmission device and a subscriber side transmission device, which are opposed to each other, transmit and receive signal light via an optical fiber, and switches the route of the optical fiber to a working optical fiber or an emergency optical fiber,
an optical path changeover switch for switching between the working optical fiber and the emergency optical fiber;
a WDM coupler for splitting the wavelength of a power supply optical signal emitted from a power supply device;
an opto-electrical converter for converting the power supply optical signal demultiplexed by the WDM coupler into an electric signal;
a power storage device that stores the electricity output from the photoelectric converter;
a voltage boosting device that boosts an output voltage from the power storage device to a voltage required to operate the optical path changeover switch;
a control device that monitors an output voltage from the photoelectric converter, monitors a voltage of the power storage device, controls the voltage boost device, and controls a power supply and path switching of the optical path changeover switch;
Equipped with.

Specifically, the optical fiber route switching method of the present disclosure includes:
A method for switching a path of a station-side transmission device and a subscriber-side transmission device in an optical transmission line for transmitting and receiving an optical signal via an optical fiber, the method being performed by an optical fiber path switching device for switching a path of the optical fiber to a working optical fiber or an emergency optical fiber, the method comprising the steps of:
The WDM coupler splits the power supply optical signal emitted from the power supply light source device,
an optical/electrical converter converts the power supply optical signal demultiplexed by the WDM coupler into an electrical signal;
a power storage device that stores the electricity output from the photoelectric converter;
a voltage boosting device that boosts an output voltage from the power storage device to a voltage required to operate the optical path changeover switch;
An optical path changeover switch switches between the working optical fiber and the emergency optical fiber using the power stored in the power storage device.

This disclosure makes it possible to realize optical path switching by supplying weak optical power.

1 shows an example of the configuration of an optical fiber route switching system. 2 shows an example of the configuration of a power supply light source device. 2 shows an internal configuration of a power storage device in an optical fiber route switching device. 1 shows an optical fiber path switching method using an optical fiber path switching device. 1 shows an example of the configuration of an optical fiber route switching system.

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.

Below, an embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 shows an embodiment of the present disclosure. The optical fiber path switching system of the present disclosure includes a power supply light source device 2 that emits a power supply optical signal, and an optical fiber path switching device. The optical fiber path switching device is used in an optical transmission path in which an opposing station side transmission device 100 and a subscriber side transmission device 101 transmit and receive signal light via an optical fiber, and is placed in an environment where it is difficult to secure a power source, such as in an underground manhole or in a closure installed above ground. The power supply light source device 2 is installed in a communication building where the station side transmission device 100 is installed. The optical fiber path switching device is supplied with power by optical power supply from the power supply light source device 2, and switches the path to the current optical fiber 102 or the emergency optical fiber 103 as the optical fiber.

More specifically, the optical fiber route switching device of the present disclosure comprises:
a WDM (Wavelength Division Multiplexing) coupler 3 that multiplexes or splits the wavelengths of the power supply optical signal emitted from the power supply device 2;
an optical path changeover switch 1 for switching between a working optical fiber 102 and an emergency optical fiber 103;
a photoelectric converter 4 for converting the optical energy of the power supply optical signal emitted from the power supply light source device 2 into electrical energy;
a storage device 5 that stores the electric energy converted by the photoelectric converter 4;
a voltage boosting device 6 that boosts the output voltage from the power storage device 5 to a voltage required to operate the optical path changeover switch 1;
an optical path changeover switch power switch 7 for controlling the power supply to the optical path changeover switch 1;
a control device 8 that monitors the output voltage from the photoelectric converter 4, monitors the voltage of the power storage device 5, controls the voltage boost device 6, and controls the power supply and path switching of the optical path changeover switch 1;
Equipped with.

The power supply optical signal emitted from the power supply light source device 2 is multiplexed onto the current optical fiber 102 at the optical branching coupler 104 installed in the communication building. The power supply optical signal multiplexed onto the current optical fiber 102 is separated by the WDM coupler 3 and supplied to the photoelectric converter 4.

The optical signal for power supply is converted to electricity in the photoelectric converter 4 and supplied to the power storage device 5. The power storage device 5 stores the electricity supplied from the photoelectric converter 4. The power stored in the power storage device 5 is supplied to the control device 8 and the voltage boost device 6.

The control device 8 monitors the voltage converted by the photoelectric converter 4 using a photoelectric converter output voltage monitoring signal line 9. The control device 8 also monitors the voltage of the electricity stored in the storage device 5 via a storage device voltage monitoring signal line 10. This makes it possible to determine whether or not the power required for the optical path switching operation in the optical path switching switch 1 is stored.

The voltage boost device 6 boosts the voltage of the electricity stored in the power storage device 5 to a voltage level required for the operation of the optical path switching switch 1. The electricity boosted by the voltage boost device 6 is supplied or stopped to the optical path switching switch 1 by the optical path switching switch power switch 7. In this way, the present disclosure can supply the optical path switching switch 1 with the power required for the optical path switching switch 1.

The start and stop of the voltage boost device 6 is controlled by the control device 8 via the voltage boost device control signal line 13. The ON/OFF of the optical path switching switch power switch 7 is controlled by the control device 8 via the optical path switching switch power control signal line 12. The control device 8 supplies the optical path switching switch 1 with the power required for the optical path switching operation, and then the control device 8 switches the optical path via the optical path switching switch control signal line 11.

Here, in this disclosure, power from the power storage device 5 is supplied in the order of the voltage boost device 6, the optical path switching power switch 7, and the optical path switching switch 1. Therefore, in this disclosure, the voltage boost device 6 is started, the optical path switching power switch 7 is turned ON, and the optical path switching of the optical path switching switch 1 is performed in this order.

In these configurations, only the control device 8 and the power storage device 5 operate under normal conditions. The control device 8 charges the power storage device 5 while checking whether the power stored in the power storage device 5 is sufficient to operate the optical path changeover switch 1. By operating the entire system with the minimum necessary power, it is possible to ensure enough power to operate the optical path changeover switch 1 even with the minute power of about 0.5 mW obtained by optical power supply.

Therefore, even with a weak optical energy of about 0.5 mW of the power supply optical signal, the optical path changeover switch 1 can perform optical fiber path switching from the working optical fiber 102 to the emergency optical fiber 103 and the reverse operation.

Figure 2 shows an example of remotely controlling the optical path changeover switch 1 using the power supply light source device 2. The intensity modulator 21 modulates the intensity of the light emitted from the LD light source 20 with a control signal for remotely controlling the optical path changeover switch 1. This makes it possible to transmit a control signal for remotely controlling the optical path changeover switch 1 using the power supply optical signal output from the power supply light source device 2.

The modulation of the optical output in the intensity modulator 21 is realized by controlling the intensity modulator 21 through the optical fiber path switching instruction signal line 23 by an optical fiber path switching instruction device 24 such as a computer. The power supply optical signal modulated by the intensity modulator 21 is converted to electricity in the photoelectric converter 4. By monitoring the output voltage from the photoelectric converter 4 at this time with the control device 8, it is possible to receive the control signal output from the optical fiber path switching instruction device 24.

Figure 3 shows an embodiment of the power storage device 5. The power storage device 5 includes a control device capacitor 52 for supplying power to the control device 8, and an optical path switching capacitor 54 for supplying power to the optical path switching switch 1. Power from the photoelectric converter 4 is supplied to two systems, the control device capacitor 52 and the optical path switching switch capacitor 54. A control device capacitor backflow prevention diode 51 is connected between the photoelectric converter 4 and the control device capacitor 52, and an optical path switching switch capacitor backflow prevention diode 53 is connected between the photoelectric converter 4 and the optical path switching switch capacitor 54.

The power stored in these two systems of capacitors 52 for the control device and capacitors 54 for the optical path changeover switch does not flow back and forth between the two systems of capacitors due to the backflow prevention diodes 51 for the capacitor for the control device and the backflow prevention diodes 53 for the capacitor for the optical path changeover switch. As a result, even if a large amount of power is temporarily consumed from the capacitor 54 for the optical path changeover switch to operate the optical path changeover switch 1, this does not affect the capacitor 52 for the control device, and it is possible to continue stable operation of the control device 8.

The power from the photoelectric converter 4 is first charged to the control device capacitor 52. The charging voltage of the control device capacitor 52 is monitored by the optical path switching switch capacitor charging controller 56 via the control device capacitor voltage monitoring signal line 57. When the charging voltage of the control device capacitor 52 reaches or exceeds the set voltage, the optical path switching switch capacitor charging controller 56 controls the optical path switching switch capacitor charging control switch 55, and starts charging the optical path switching switch capacitor 54 from the optical path switching switch capacitor charging control switch 55.

With these configurations, the power from the photoelectric converter 4 is first charged to the control device capacitor 52. The power charged in the control device capacitor 52 is immediately supplied to the control device 8, which starts up first. Then, as the control device 8 starts up, it can start monitoring the output voltage of the photoelectric converter 4 and the voltage of the storage device 5. Therefore, the optical fiber path switching device of the present disclosure can switch the optical fiber path from the active optical fiber 102 to the emergency optical fiber 103, or from the emergency optical fiber 103 to the active optical fiber 102, only when it receives an optical fiber path switching instruction from the optical fiber path switching instruction device 24 and determines that there is enough power to operate the optical path switching switch 1.

FIG. 4 illustrates an example of an optical fiber path switching method using an optical fiber path switching device according to an embodiment of the present disclosure.
In the photoelectric converter output voltage monitoring step S70, the time and number of times that the output voltage from the photoelectric converter 4 has dropped from, for example, 2V or more (HIGH) to 0.5V or less (LOW) are monitored. By making the output voltage LOW correspond to a digital 1 and the output voltage HIGH correspond to a digital 0, it is possible to receive a switching command to the optical path changeover switch 1 that combines 1 and 0. Also, if the output voltage remains LOW for a certain period of time or longer, it is possible to determine that the working optical fiber 102 has been broken. In this way, in the photoelectric converter output voltage monitoring step S70, it is determined whether the received switching command is for "emergency" or "working", and whether the working optical fiber 102 is "broken" or "normal".

If the result of the determination is "emergency use" or "current use", the voltage of the storage device 5 is measured in the storage device voltage monitoring step S71. If the voltage is below a specified value, the voltage of the storage device 5 is measured again in the storage device voltage monitoring step S71 after a certain period of time. If the voltage is greater than the specified value, the voltage boost device 6 starts boosting in the voltage boost device control step S72.

Next, in optical path switch power control step S73, power supply to the optical path switch 1 is started, and in optical path switch control step 74, the optical path switch 1 is operated to switch the optical path to "emergency" or "active" according to the received switching command. After the optical path is switched, power supply to the optical path switch 1 is terminated in optical path switch power control step S73, and boosting by the voltage booster 6 is terminated in voltage booster control step S72.

On the other hand, if a "break" in the working optical fiber 102 is determined in the photoelectric converter output voltage monitoring step S70, the optical path changeover switch 1 immediately switches to the emergency optical fiber 103.

First, the voltage boost device 6 starts boosting in step S72, power is supplied to the optical path changeover switch 1 in step S73 for controlling the optical path changeover switch power supply, and the optical path changeover switch 1 is switched to the emergency optical fiber 103 in step S74 for controlling the optical path changeover switch.

Then, the output voltage of the photoelectric converter 4 is monitored in the photoelectric converter output voltage monitoring step S70. If it is determined that the output voltage becomes HIGH and the current optical fiber 102 has returned to "normal", the process returns to the storage device voltage monitoring step S71 of the flow determined to be "current" in the photoelectric converter output monitoring step S70, and when the storage voltage becomes greater than the specified value, the optical path changeover switch 1 is switched to the current optical fiber 102.

In addition, when the power of the storage device 5 becomes 0 due to a "disconnection" state and the current optical fiber 102 returns to "normal", power storage from 0 is required to resume the photoelectric converter output voltage monitoring process 70. Therefore, by providing a WDM coupler 111 and an optical coupler 110 to the emergency optical fiber 103 as shown in FIG. 5, the power supply optical signal propagated using the emergency optical fiber 103 can be demultiplexed by the WDM coupler 111. As a result, even if the current optical fiber 102 is in a "disconnection" state, a small amount of power can be supplied, allowing some power to be stored in the storage device 5, and enabling the photoelectric converter output voltage monitoring process 70 to be immediately resumed when the current optical fiber 102 returns to "normal".

In addition, by making the branching ratio of the optical branching coupler 104 unequal, for example 6:4, a difference occurs in the received light power of the photoelectric converter 4 when the current optical fiber 102 is broken and when the emergency optical fiber 103 is broken. In other words, a difference occurs in the output voltage of the photoelectric converter 4, so if a reference value is set in advance, it becomes possible to distinguish between a break in the current optical fiber 102 and a break in the emergency optical fiber 103.

In this embodiment, the case where there is one optical path changeover switch 1 has been described, but the present disclosure is not limited to this. It goes without saying that even if there are multiple optical path changeover switches 1, this can be achieved by sequentially switching them one by one while monitoring whether the necessary power is secured.

(Effects of the present disclosure)
As described above, according to the present disclosure, it is possible to switch optical fiber paths by a safe level of extremely weak optical power supply even in communication optical fibers. Therefore, even in places where it was not easy to secure a power source in the past, such as in underground manholes or in closures installed above ground, it is possible to supply power by optical power supply using existing communication optical fibers and switch optical fiber paths.

This disclosure can be applied to the information and communications industry.

1: Optical path changeover switch 2: Power supply light source device 3: WDM coupler 4: Photoelectric converter 5: Power storage device 6: Voltage boost device 7: Optical path changeover switch power switch 8: Control device 9: Photoelectric converter output voltage monitoring signal line 10: Power storage device voltage monitoring signal line 11: Optical path changeover switch control signal line 12: Optical path changeover switch power control signal line 13: Voltage boost device control signal line 20: LD light source 21: Intensity modulator 23: Optical fiber path switching instruction signal line 24: Optical fiber path switching instruction device 51: Backflow prevention diode for capacitor for control device 52: Capacitor for control device 53: Backflow prevention diode for capacitor for optical path changeover switch 54: Capacitor for optical path changeover switch 55: Capacitor charge control switch for optical path changeover switch 56: Capacitor charge controller for optical path changeover switch 57: Capacitor voltage monitoring signal line for control device 58: Capacitor charge control switch signal line for optical path changeover switch 70: Photoelectric converter output voltage monitoring step 71: Storage device voltage monitoring step 72: Voltage booster device control step 73: Optical path changeover switch power supply control step 74: Optical path changeover switch control step 100: Station side transmission device 101: Subscriber side transmission device 102: Working optical fiber 103: Emergency optical fiber 110: Optical coupler 111: WDM coupler

Claims (5)

An optical fiber route switching device is used in an optical transmission path in which a station side transmission device and a subscriber side transmission device, which are opposed to each other, transmit and receive signal light via an optical fiber, and switches the route of the optical fiber to a working optical fiber or an emergency optical fiber,
an optical path changeover switch for switching between the working optical fiber and the emergency optical fiber;
a WDM coupler for demultiplexing a wavelength of a power supply optical signal generated from a power supply device and multiplexed onto the working optical fiber ;
an opto-electrical converter for converting the power supply optical signal demultiplexed by the WDM coupler into an electric signal;
a power storage device that stores the electricity output from the photoelectric converter;
a voltage boosting device that boosts an output voltage from the power storage device to a voltage required to operate the optical path changeover switch;
a control device that monitors an output voltage from the photoelectric converter, monitors a voltage of the power storage device, controls the voltage boost device, and controls a power supply and path switching of the optical path changeover switch;
An optical fiber path switching device comprising: The power storage device is
a control device capacitor for storing power for operating the control device;
an optical path switching capacitor for storing power for operating the optical path switching switch;
a capacitor charge control switch for controlling the start and end of charging the capacitor for the optical path switching switch;
a capacitor charge controller for the optical path switching switch that monitors a voltage of the capacitor for the control device and controls the capacitor charge control switch for the optical path switching switch so as to start charging the capacitor for the optical path switching switch when the voltage of the capacitor for the control device becomes equal to or higher than a set voltage;
2. The optical fiber route switching device according to claim 1, comprising: The power storage device is
a control device capacitor backflow prevention diode connected between the photoelectric converter and the control device capacitor for preventing backflow from the control device capacitor;
a capacitor backflow prevention diode for an optical path switching switch, connected between the photoelectric converter and the capacitor for the optical path switching switch, for preventing backflow from the capacitor for the optical path switching switch;
3. The optical fiber route switching device according to claim 2, comprising: the power supply optical signal is intensity-modulated by a control signal for remotely operating the optical path changeover switch,
the control device acquires the control signal from the electrical signal output from the photoelectric converter, and switches the optical path changeover switch in accordance with the acquired control signal.
4. An optical fiber route switching device according to claim 1, wherein: A method for switching a path of a station-side transmission device and a subscriber-side transmission device in an optical transmission line for transmitting and receiving an optical signal via an optical fiber, the method being performed by an optical fiber path switching device for switching a path of the optical fiber to a working optical fiber or an emergency optical fiber, the method comprising the steps of:
a WDM coupler that demultiplexes the power supply optical signal emitted from the power supply light source device and multiplexed in the working optical fiber ;
an optical/electrical converter converts the power supply optical signal demultiplexed by the WDM coupler into an electrical signal;
a power storage device that stores the electricity output from the photoelectric converter;
a voltage boosting device for boosting an output voltage from the power storage device to a voltage required for operating the optical path changeover switch;
the optical path changeover switch switches between the working optical fiber and the emergency optical fiber using the power stored in the power storage device;
The optical fiber route switching device includes:
When a control signal for the optical path changeover switch is received using the power supply optical signal,
After activating the optical path changeover switch, switching between the working optical fiber and the emergency optical fiber in accordance with the control signal.
The method characterized by:

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