WO2023116134A1

WO2023116134A1 - Detection device and optical fiber detection method

Info

Publication number: WO2023116134A1
Application number: PCT/CN2022/124640
Authority: WO
Inventors: 陈飞; 艾凡; 张基彪
Original assignee: 华为技术有限公司
Priority date: 2021-12-23
Filing date: 2022-10-11
Publication date: 2023-06-29
Also published as: CN116337199A

Abstract

A detection device (2000) and an optical fiber detection method, for use in reducing the bandwidth occupation of a detection signal. The detection device (2000) comprises: a light source assembly (2100) for acquiring a first optical signal, the first optical signal being a modulated single-channel wavelength signal; an optical path unit (2200) for acquiring a first feedback signal of an optical fiber to be detected obtained by the first optical signal by means of a delay optical path; and an operation unit (2300) for determining a vibration state of said optical fiber according to the first feedback signal.

Description

A detection device and optical fiber detection method

This application claims priority to a Chinese patent application filed with the State Intellectual Property Office of China on December 23, 2021, with application number 202111595320.2 and titled "A Detection Device and Optical Fiber Detection Method", the entire contents of which are hereby incorporated by reference Applying.

technical field

The embodiments of the present application relate to the field of optical communications, and in particular, to a detecting device and an optical fiber detecting method.

Background technique

Optical fiber detection technology realizes functions such as early warning of disconnection and earthquake by detecting the vibration state of optical fiber. Specifically, the detection device inputs the detection signal into a delayed optical path connected to the optical fiber to be tested, wherein the delayed optical path includes two optical paths with different optical lengths. Therefore, the detection signal received by the detection device includes two signals that have traveled the same optical path in the feedback signal in the optical fiber to be tested, and interferes with each other at the detection device. When vibration occurs in the optical fiber to be tested, the interference of the above-mentioned same optical path signal is strengthened. Therefore, the optical fiber under test vibrates, and the vibration amplitude suddenly increases at the detection equipment.

In order to prevent misjudgment of the vibration state, the difference between the vibration amplitudes of the corresponding detection equipment before and after the occurrence of optical fiber vibration should be increased as much as possible. Therefore, it is necessary to make the coherence between the feedback signals as small as possible when there is no vibration. As the spectral width of the optical signal is wider, the coherence is lower. Therefore, broad-spectrum light is used as the detection signal to enhance the amplitude difference before and after the vibration of the optical fiber to be tested.

However, the wider the spectral width of the detection signal, the more fiber bandwidth will be occupied, so that the service signal and the detection signal cannot be transmitted at the same time, and the bandwidth of the service signal light will be reduced due to the occupation of the optical fiber bandwidth by the detection signal.

Contents of the invention

Embodiments of the present application provide a detection device and an optical fiber detection method, which are used to reduce the bandwidth occupation of detection signals, thereby reserving a larger bandwidth for service signals.

In a first aspect, the embodiment of the present application provides a detection device, including: a light source component, an optical path unit, and a computing unit.

Wherein, the light source component is used to obtain the first optical signal, and the first optical signal is a modulated single-channel wavelength signal. The optical path unit is used to obtain the first feedback signal of the optical fiber under test obtained by passing the first optical signal through the delayed optical path. The computing unit is used for determining the vibration state of the optical fiber to be tested according to the first feedback signal.

In the embodiment of the present application, the first optical signal (modulated single-channel wavelength signal) is used as a detection signal and input into the optical fiber to be tested through the delay optical path to detect the vibration state of the optical fiber. Since the bandwidth occupied by the single-channel wavelength signal is small, the bandwidth occupied by the optical fiber to be tested can be reduced, thereby increasing the bandwidth reserved for service signals. In addition, the detection signal is a modulated single-channel wavelength signal, and the coherence of the detection signal is reduced by modulation, thereby increasing the difference between the vibration amplitudes of the corresponding detection equipment before and after the occurrence of optical fiber vibration, and improving the accuracy of vibration state judgment .

Optionally, in this embodiment of the present application, 0.05nm≤the wavelength of the single-channel wavelength signal≤3nm.

The wavelength range (bandwidth range) of the existing wide-spectrum detection signal is usually around 20-60nm. The embodiment of the present application greatly reduces the wavelength range of the detection signal through a single-channel wavelength signal, thereby occupying less bandwidth.

In an optional implementation manner, the light source assembly includes a laser driving circuit and a laser. The laser drive circuit is used to obtain the modulated electrical signal, and the laser is used to generate the first optical signal according to the modulated electrical signal.

In the embodiment of the present application, the modulated electrical signal obtained by the laser drive circuit makes the first optical signal output by the light source component a modulated single-channel wavelength signal. Due to the small size of the laser drive circuit, simple manufacturing process and low assembly accuracy requirements , so this structure can reduce the volume of detection equipment and the complexity of processing technology.

In an optional implementation manner, the laser driving circuit includes a continuous laser modulator (laser diode driver, LDD), and the continuous LDD is used to drive the laser driver to generate the first optical signal according to the modulated electrical signal.

The detection device detects the vibration state by obtaining continuous feedback signals. Therefore, in the embodiment of the present application, the continuous driving of the laser is realized through continuous LDD, and continuous first optical signals are obtained, thereby obtaining continuous first feedback signals. Detection of the vibration state of the signal to be tested.

In an optional implementation manner, the modulated electrical signal includes a phase modulated signal, an amplitude modulated signal or a frequency modulated signal.

In the embodiment of the present application, the coherence of the modulated electrical signal is reduced by phase modulation, amplitude modulation or frequency modulation of the electrical signal, thereby reducing the coherence of the first optical signal (detection signal), thereby increasing the optical fiber vibration before and after occurrence. The size difference between the vibration amplitudes at the corresponding detection equipment improves the accuracy of vibration state judgment.

In an optional implementation manner, the phase modulation electrical signal is a pseudo-random code signal.

In the embodiment of the present application, the first optical signal is generated according to the pseudo-random code signal, thereby reducing the coherence of the first optical signal (detection signal). Since the pseudo-random code signal is a common electrical signal, the acquisition method is simple and the required circuit structure is simple. Therefore, the circuit complexity of the laser driving circuit can be reduced, thereby reducing the volume and failure rate of the light source assembly, thereby reducing the volume and failure rate of the entire detection device.

In an optional implementation manner, the light source component includes a laser and a modulation device. The laser is used to obtain a light beam with a single-channel wavelength; the modulation device is used to modulate the light beam with a single-channel wavelength to obtain a first optical signal.

In the embodiment of the present application, the modulation device is used to modulate the beam of single-channel wavelength, so that the coherence of the first optical signal (detection signal) obtained through modulation is low, thereby increasing the difference between the vibration amplitudes of the corresponding detection equipment before and after the fiber vibration occurs. The size difference between them improves the accuracy of judging the vibration state. Since the modulation device is a passive modulation device for modulating the light beam, no additional signal needs to be input for modulation. Therefore, this structure does not require the laser to generate beams according to the input signal, which can simplify the structure of the laser, thereby reducing the volume and structural complexity of the light source component, and further reducing the volume and structural complexity of the entire detection device.

In an optional implementation manner, the modulation device includes a semiconductor optical amplifier (semiconductor optical amplifier, SOA) or a lithium niobate phase modulator.

In an optional implementation manner, the modulation device is specifically configured to: perform phase modulation, amplitude modulation, or frequency modulation on a light beam with a single-channel wavelength to obtain a first optical signal.

In an optional implementation manner, the light source component is specifically configured to: acquire a first optical signal with a rate greater than or equal to 155 Mbit/s.

Since the higher the rate of the signal, the lower the coherence, therefore, in the embodiment of the present application, the rate of the first signal light acquired by the light source component is greater than or equal to 155 Mbit/s. Therefore, the coherence of the first optical signal (detection signal) is reduced, thereby increasing the difference between the vibration amplitudes of the corresponding detection equipment before and after the occurrence of optical fiber vibration, and improving the accuracy of vibration state judgment.

In an optional implementation manner, the optical path unit includes a delay optical path, and the delay optical path is used to: adjust the optical path of at least one path of light in the first optical signal (that is, to make at least two paths of light in the first optical signal travel There is an optical path difference between the optical paths), to obtain a second optical signal, and the second optical signal is formed by coupling two optical signals with different optical paths. and inputting the second optical signal into the optical fiber to be tested to obtain a third optical signal; The optical signal is coupled.

In the embodiment of the present application, the delay optical path is integrated inside the detection device, and the detection of the vibration state of the optical fiber to be tested can be realized by connecting the detection device to the optical fiber to be tested, which simplifies the structure of the entire detection system. Moreover, the delay optical path is used to adjust the optical path of at least one path of light in the first signal light, and the specific adjusted optical path may affect the accuracy of the final test result (for example: if the adjusted optical path is equal to a phase, then the adjusted optical path is equal to a phase. The phases of the two paths of light of the first optical signal may be the same, resulting in high coherence of the first optical signal and inaccurate test results). Therefore, by integrating the delay optical path inside the detection device, an appropriate optical path length can be determined for the delay optical path during the design and production stages of the detection device, thereby ensuring the accuracy of vibration detection results.

In an optional implementation manner, the optical path unit is specifically configured to: input the first optical signal into the delayed optical path, and the delayed optical path is used to input the second optical signal obtained based on the first optical signal into the optical fiber under test to obtain the third optical signal signal; wherein, the second optical signal is formed by coupling two optical signals with different optical paths (that is, there is an optical path difference between the optical paths traveled by at least two optical paths in the second optical signal). And, receiving the first feedback signal from the delayed optical path, the first feedback signal is obtained by adjusting the optical path of at least one optical path of the third optical signal in the optical fiber to be tested, and the first feedback signal is coupled by two optical signals with the same optical path become.

In the embodiment of the present application, placing the delay optical path outside the detection device can reduce the structural complexity and volume of the detection device. Moreover, for different optical fibers to be tested and/or modulated electrical signals and/or first optical signal rates, delay optical paths with different optical path differences can be matched, which improves the adaptability of the detection device to different application scenarios.

In an optional implementation manner, the delay optical path includes at least one of a delay lens, a mirror group, and two optical fibers with different optical paths.

In the embodiment of the present application, the structure of the time-delay lens and the reflection mirror group is simple and small, which can reduce the volume of the detection equipment or the entire detection system.

For two optical fibers with different optical paths, the control method for the optical path difference is simple, the structural precision is not high, the assembly requirements are not high, and the requirements for processing technology are relatively low. Moreover, the optical path difference of the two optical fibers with different optical paths can be adjusted. If the optical fiber to be tested and/or the modulated electrical signal and/or the rate of the first optical signal are adjusted, the two optical fibers can be adjusted accordingly, thereby improving the The flexibility of the detection equipment improves the adaptability of the detection equipment to different application scenarios.

In an optional implementation manner, the optical path unit is specifically configured to: input the first optical signal into the delay optical path, and at the same time input the service signal into the target optical fiber connected to the optical fiber to be tested; The second optical signal obtained through the process adjustment and the service signal are simultaneously transmitted in the optical fiber to be tested.

In the existing vibration state detection technology, due to the large bandwidth of the wide-spectrum detection light source, it occupies the transmission bandwidth of the service signal, and the vibration state detection requires continuous transmission of detection signals, so the vibration state detection will cause Interruption of traffic signal transmission. In the embodiment of the present application, since the bandwidth of the first optical signal (detection signal) is relatively small, it can be transmitted in the optical fiber to be tested simultaneously with the service signal (for example, in the optical fiber to be tested, two signals can be simultaneously transmitted through wavelength division multiplexing. Transmission), so as to realize the transmission of business signals while detecting the vibration state. Therefore, through the detecting device provided in the embodiment of the present application, the service signal transmission will not be interrupted while detecting the vibration state.

In an optional implementation manner, the light source assembly further includes a burst laser driver LDD, and the burst LDD is used to excite the laser to obtain a square-wave optical pulse signal. The optical path unit is also used for sending a square-wave optical pulse signal to the optical fiber to be tested; and receiving a second feedback signal of the square-wave optical pulse signal in the optical fiber to be tested. The computing unit is also used to determine the link quality of the optical fiber to be tested according to the second feedback signal.

In the embodiment of the present application, the burst LDD excitation laser is used to obtain the square-wave optical pulse signal to realize the detection of the quality of the optical fiber link. Therefore, the detection equipment provided by the embodiment of the present application can not only realize the detection of the vibration state, but also realize the detection of the quality of the optical fiber. Moreover, two detection states can share one laser, which reduces the number of lasers in the detection device, thereby reducing the structural complexity and volume of the detection device.

Moreover, the burst LDD is electrically connected to the laser instead of optically connected, and the optical path has less restrictions on the access structure, and the access method is flexible, which makes the structure of the detection device more flexible, and the structure complexity and volume are smaller.

In an optional implementation manner, the optical path unit is specifically configured to: at the first moment, send a square-wave optical pulse signal to the optical fiber to be tested; at the second moment, send the first optical signal to the delay optical path; or, at the second At this moment, a second optical signal is sent to the optical fiber to be tested, and the second optical signal is obtained by adjusting the optical path of the first optical signal by the delay optical path.

In the embodiment of the present application, the detection of the vibration state of the optical fiber and the quality of the optical fiber is realized by means of time division multiplexing. Therefore, the parallel execution of the two kinds of detection can be realized without interrupting any kind of detection, thereby realizing the continuous acquisition of the real-time vibration state and real-time quality of the optical fiber.

In the second aspect, the embodiment of the present application also provides an optical fiber detection method, including:

The detecting device acquires the first optical signal, and the first optical signal is a modulated single-channel wavelength signal. Then, the detecting device acquires a first feedback signal of the optical fiber to be tested obtained by passing the first optical signal through a delay optical path. Then, the detection device determines the vibration state of the optical fiber to be tested according to the first feedback signal.

For the beneficial effects of the second aspect, please refer to the first aspect, which will not be repeated here.

Description of drawings

Figure 1a is a schematic diagram of an application architecture of a detection device provided by an embodiment of the present application;

Figure 1b is a schematic diagram of another application architecture of the detection device provided by the embodiment of the present application;

Figure 1c is a schematic diagram of a detection result of the detection device provided by the embodiment of the present application;

FIG. 2 is a schematic structural diagram of a detection device provided by an embodiment of the present application;

Fig. 3 is another structural schematic diagram of the detection equipment provided by the embodiment of the present application;

Fig. 4 is another structural schematic diagram of the detection equipment provided by the embodiment of the present application;

Fig. 5 is another structural schematic diagram of the detection equipment provided by the embodiment of the present application;

FIG. 6 is a schematic diagram of another application architecture of the detection device provided by the embodiment of the present application;

Fig. 7 is another schematic structural diagram of the detection equipment provided by the embodiment of the present application;

FIG. 8 is a schematic diagram of another application architecture of the detection device provided by the embodiment of the present application;

FIG. 9 is another schematic structural diagram of the detection device provided by the embodiment of the present application;

FIG. 10 is a schematic diagram of another application architecture of the detection device provided by the embodiment of the present application;

FIG. 11 is a schematic flow chart of an optical fiber detection method provided by an embodiment of the present application.

Detailed ways

Fig. 1a is a schematic diagram of an application architecture of a detection device provided by an embodiment of the present application. As shown in Figure 1a, in this architecture, the detection device is connected to the optical fiber to be tested, and the detection device sends a detection signal to the optical fiber to be tested and receives a feedback signal from the optical fiber to be tested. The detection equipment determines whether the optical fiber under test vibrates through the feedback signal.

Optionally, as shown in FIG. 1b, a delay optical path (also called a sagnac interferometer) may be connected between the detection device and the optical fiber to be tested, and it is determined whether the optical fiber vibrates by demodulating the interference signal. The principle is as follows:

As shown in Figure 1b, in the delay path, two optical fibers with different optical paths are connected between two couplers, where the optical path of fiber 1 (delay fiber) is longer than that of fiber 2 (common fiber). The detection signal is input into the delay optical path. Since the optical paths of the two optical fibers between the two couplers are different, the optical paths of the two optical beams received by the optical fiber to be tested are different. The end of the optical fiber to be tested is reflected by a Faraday reflector or suspended in the air, and the delay optical path can receive two feedback beams from the optical fiber to be tested. The two feedback light beams pass through two optical fibers with different optical paths in the delay optical path, and four return light beams are obtained at the detection device. The four beams are:

The light beam 1 passes through the optical fiber 1 in the direction from the detection equipment to the optical fiber to be tested, and passes through the optical fiber 1 in the direction from the optical fiber to be tested to the detection equipment.

The light beam 2 passes through the optical fiber 1 in the direction from the detection equipment to the optical fiber to be tested, and passes through the optical fiber 2 in the direction from the optical fiber to be tested to the detection equipment.

The light beam 3 passes through the optical fiber 2 in the direction from the detection equipment to the optical fiber to be tested, and passes through the optical fiber 1 in the direction from the optical fiber to be tested to the detection equipment.

The light beam 4 passes through the optical fiber 2 in the direction from the detection equipment to the optical fiber to be tested, and passes through the optical fiber 2 in the direction from the optical fiber to be tested to the detection equipment.

Since the optical distances of optical fiber 1 and optical fiber 2 are different, only the optical distances of beam 2 and beam 3 among the above four beams are the same. Interference will occur at the detection device. When the optical fiber to be tested vibrates, the interference between beam two and beam three is strengthened. The waveform diagram corresponding to the detection equipment is shown in Figure 1c. It can be known that when the optical fiber to be tested vibrates, a sharp increase in the vibration amplitude will appear in the waveform diagram.

In order to prevent misjudgment, it is necessary to control the amplitude when there is no vibration as much as possible, so it is necessary to make the coherence of the light source with the same path when the optical fiber under test is not vibrated should be small. Since the spectral width is narrower, the coherence of the return beam is higher and the amplitude is larger. Therefore, broad-spectrum light (usually in the wavelength range of 20-60nm) is usually used as the detection signal to ensure that the amplitude difference between vibration does not occur and occurs is large.

However, the wider the spectral width of the detection signal, the more fiber bandwidth is occupied, resulting in a larger fiber bandwidth occupied by the fiber detection. As a result, the service signal cannot be transmitted simultaneously with the detection signal, and the bandwidth of the service signal light is reduced because the detection signal occupies the bandwidth of the optical fiber.

In order to solve the above problems, an embodiment of the present application provides a detection device. Referring to FIG. 2 , based on the architecture shown in FIGS. 1 a to 1 c , the embodiment of the present application provides a detection device 2000 , including a light source assembly 2100 , an optical path unit 2200 and a computing unit 2300 .

Wherein, the light source assembly 2100 is used for acquiring the first light signal. The first optical signal is a modulated single-channel wavelength signal. The optical path unit 2200 is used to obtain the first feedback signal of the optical fiber under test obtained by delaying the first optical signal through the optical path. The computing unit 2300 is used for determining the vibration state of the optical fiber to be tested according to the first feedback signal.

In the embodiment of the present application, where 0.05nm≤the wavelength of the single-channel wavelength signal≤3nm, the modulated single-channel wavelength signal (ie, the first optical signal) is input as a detection signal into the optical fiber to detect the vibration state of the optical fiber. Since the wavelength range (bandwidth range) of the existing wide-spectrum detection signal is usually about 20-60 nm, the embodiment of the present application greatly reduces the wavelength range of the detection signal by using a single-channel wavelength signal, thereby occupying less bandwidth.

Optionally, the rate of the first optical signal acquired by the light source component is greater than or equal to 155 Mbit/s. Since the higher the rate of the signal, the lower the coherence, so in the embodiment of the present application, the rate of the first signal light acquired by the light source component 2100 is made to be greater than or equal to 155 Mbit/s. Therefore, the coherence of the first optical signal (detection signal) is reduced, thereby increasing the difference between the vibration amplitudes of the corresponding detection equipment 2000 before and after the occurrence of optical fiber vibration, and improving the accuracy of vibration state judgment.

The structure shown in Figure 2 is an overview of the structure of the detection equipment provided by the embodiment of the present application. Different components in the detection equipment may have different compositions. Next, different structures of the detection equipment provided by the embodiment of the application will be described separately.

First, the light source components are different.

In the detection device 2000 provided in the embodiment of the present application, the light source component 2100 is used to acquire the first optical signal (modulated single-channel wavelength signal). As an example, the modulated single-channel wavelength signal can be obtained through electrical modulation or optical modulation, which will be described next:

1. Acquire the first signal (modulated single-channel wavelength signal) through electrical modulation.

As shown in FIG. 3 , the light source assembly 2100 may include a laser driving circuit 2110 and a laser 2120 . Wherein, the laser driving circuit 2110 is used to obtain the modulated electrical signal, and the laser 2120 is used to generate the first optical signal (modulated single-channel wavelength signal) according to the modulated electrical signal.

In the embodiment of the present application, the modulated electrical signal obtained by the laser drive circuit 2110 makes the first optical signal output by the light source assembly 2100 a modulated single-channel wavelength signal. The precision requirement is low, so this structure can reduce the volume and processing complexity of the detection device 2000 .

In the embodiment of the present application, since the spectral width of the single-channel wavelength signal is relatively narrow, the coherence is strong. Therefore, the modulated single-channel wavelength signal is used as the first optical signal (detection signal), and the modulation makes the pulse width of the single-channel wavelength signal broaden, reducing coherence, so that the modulated single-channel wavelength signal can be used as the fiber vibration state Detect probes in the scene.

Optionally, the modulated electrical signal may include a phase modulated signal, an amplitude modulated signal or a frequency modulated signal. By phase modulation, amplitude modulation or frequency modulation of the electrical signal, the coherence of the modulated electrical signal is reduced, thereby reducing the coherence of the first optical signal (that is, the detection signal), thereby increasing the corresponding detection equipment 2000 before and after the occurrence of optical fiber vibration The size difference between vibration amplitudes can improve the accuracy of vibration state judgment.

Optionally, the phase modulation signal may include a pseudo-random code signal. The first optical signal is generated according to the pseudo-random code signal, thereby reducing the coherence of the first optical signal (detection signal). Since the pseudo-random code signal is a common electrical signal, the acquisition method is simple and the required circuit structure is simple. Therefore, the circuit complexity of the laser driving circuit 2110 can be reduced, thereby reducing the volume and failure rate of the light source assembly 2100 , and further reducing the volume and failure rate of the entire detection device 2000 .

Optionally, the laser driving circuit 2110 may include a continuous laser driver (laser diode driver, LDD) 2111, and the continuous LDD 2111 is used to drive the laser 2120 to generate the first optical signal according to the modulated electrical signal.

The detection device 2000 detects the vibration state by obtaining continuous feedback signals, realizes the continuous driving of the laser through the continuous LDD 2111, obtains the continuous first optical signal, thereby obtains the continuous first feedback signal, and realizes the vibration state of the signal to be tested detection.

Optionally, the laser driving circuit 2110 may also include a field programmable gate array (field programmable gate array, FPGA) chip or a microcontroller unit (microcontroller unit, MCU) chip. The FPGA chip and the MCU chip are used to obtain the aforementioned modulated electrical signal.

Optionally, the detecting device 2000 may further include a photodetector 2400 . The photodetector 2400 is used to convert the first feedback signal (optical signal) from the optical path unit 2200 into an electrical signal, and send the electrical signal to the calculation unit 2300, so that the calculation unit 2300 can determine the vibration state of the optical fiber according to the electrical signal. detection.

2. Obtain the first signal (modulated single-channel wavelength signal) through optical modulation.

As shown in FIG. 4 , the light source assembly 2100 may include a laser 2120 and a modulation device 2130 . Wherein, the laser 2120 is used to obtain a light beam with a single-channel wavelength, and the modulation device 2130 is used to modulate the light beam with a single-channel wavelength to obtain a first optical signal.

In the embodiment of the present application, the modulation device 2130 is used to modulate the beam of single-channel wavelength, so that the coherence of the modulated first optical signal (detection signal) is low, thereby increasing the vibration at the corresponding detection device 2000 before and after the fiber vibration occurs. The size difference between amplitudes improves the accuracy of vibration state judgment. Since the modulation device 2130 is a passive modulation device for modulating the light beam, no additional signal needs to be input for modulation. Therefore, this structure does not require the laser 2120 to generate beams according to the input signal, which can simplify the structure of the laser 2120, thereby reducing the volume and structural complexity of the light source assembly 2100, thereby reducing the volume and structural complexity of the entire detection device 2000.

Optionally, the modulation device 2130 may include a semiconductor optical amplifier (semiconductor optical amplifier, SOA) or a lithium niobate phase modulator.

Optionally, the modulation device 2130 may be specifically configured to perform phase modulation, amplitude modulation, or frequency modulation on a single-channel wavelength light beam to obtain the first optical signal.

Optionally, in addition to the different composition of the light source assembly 2100, the detection device 2000 provided in the embodiment of the present application may also include different delay optical paths, and the delay optical path may be built in or external to the detection device 2000. Next, Explain respectively:

Second, the delay optical path is different.

2.1. The delay optical path includes a delay optical fiber, and the delay optical path is built-in.

As shown in Figure 5, the optical path unit 2200 may include a delay optical path 2210, the delay optical path 2210 is also called a sagnac interferometer, including two optical fibers with different optical paths, and a coupler for coupling one end of the two optical fibers to the photodetector 2400 And a coupler for coupling the other ends of the two optical fibers with the optical fiber to be tested.

The delay optical path 2210 is used to provide an optical path difference in the outgoing direction (that is, the direction from the detection device 2000 to the optical fiber to be tested), and to provide the same light in the return direction (that is, the direction from the optical fiber to be tested to the detection device 2000). range difference. The feedback signal received by the photodetector 2400 includes two light beams with the same optical path, and the two light beams are used as the first feedback signal.

Specifically, the delay optical path 2210 is used to adjust the optical path of at least one path of light in the first optical signal to obtain the second optical signal. Wherein, the second optical signal is formed by coupling two optical signals with different optical paths (that is, there is an optical path difference between the optical paths traveled by at least two optical paths of the second optical signal). The delay optical path 2210 is also used for inputting the second optical signal into the optical fiber under test to obtain a third optical signal (ie, the feedback signal of the second optical signal through the optical fiber under test). The delay optical path 2210 is also used to adjust the optical path of at least one path of light in the third optical signal to obtain the first feedback signal. Wherein, the first feedback signal is formed by coupling two optical signals with the same optical path (that is, the aforementioned light beam 2 and light beam 3).

In the structure in which the delay optical path 2210 includes a delay fiber, the control method for the optical path difference of the two optical fibers with different optical paths is simple, the structure precision is not high, the assembly requirements are not high, and the requirements for processing technology are relatively low. Moreover, the optical path difference of the two optical fibers with different optical paths can be adjusted. If the optical fiber to be tested and/or the modulated electrical signal and/or the rate of the first optical signal are adjusted, the two optical fibers can be adjusted accordingly, thereby improving the The flexibility of the detection equipment improves the adaptability of the detection equipment to different application scenarios.

It should be noted that the light source assembly 2100 in Fig. 5 comprises continuous LDD 2111 and laser 2120, and this is only an example to the structure shown in Fig. 5 (delay optical path comprises delay optical fiber, and delay optical path is built-in), does not cause the The composition of the light source assembly 2100 is defined under the structure. In addition to the continuous LDD 2111 and the laser 2120, a laser 2120 and a modulation device 2130 may also be included, which is not limited here.

In the structure in which the delay optical path 2210 includes a delay optical fiber, the delay optical path can also be external to the detection device 2000 .

2.2. The delay optical path includes a delay optical fiber, and the delay optical path is external.

As shown in FIG. 6 , a delay optical path is connected between the detection device 2000 and the optical fiber to be tested. The delay optical path is used to provide an optical path difference in the outgoing direction (that is, the direction from the detection device 2000 to the optical fiber to be tested), and to provide the same optical path in the return direction (that is, the direction from the optical fiber to be tested to the detection device 2000) Difference. The feedback signal received by the detection device 2000 includes two beams with the same optical path, and the two beams are used as the first feedback signal.

Specifically, the optical path unit 2200 in the detection device 2000 is specifically used to: input the first optical signal into the delayed optical path, and the delayed optical path is used to input the second optical signal obtained based on the first optical signal into the optical fiber under test to obtain the third optical signal ; Wherein, the second optical signal is formed by coupling two optical signals with different optical paths (that is, there is an optical path difference between the optical paths traveled by at least two optical paths in the second optical signal). The optical path unit 2200 is also used to receive the first feedback signal from the delayed optical path. The first feedback signal is obtained by adjusting the optical path of at least one path of light in the third optical signal of the optical fiber to be tested. The first feedback signal is obtained by two paths with the same optical path. The optical signal is coupled.

In the embodiment of the present application, placing the delay optical path outside the detection device 2000 can reduce the structural complexity and volume of the detection device 2000 . Moreover, for different optical fibers to be tested and/or modulated electrical signals and/or first optical signal rates, delay optical paths with different optical path differences can be matched, which improves the adaptability of the detection device 2000 to different application scenarios.

Optionally, in addition to the delay optical fiber, the delay optical path 2210 may also include a delay lens, and the specific structure is as follows:

2.3. The delay optical path includes a delay lens, and the delay optical path is built-in.

Referring to FIG. 7 , the optical path unit 2200 may include a delay optical path 2210, and the delay optical path 2210 may include a delay lens, a beam splitter, and a beam combiner and splitter.

Wherein, on the outbound direction (that is, on the direction from the detection device 2000 to the optical fiber to be tested), the optical splitter is used to divide the first optical signal from the light source assembly 2100 into two beams (the two beams are represented by dashed lines and solid lines in the figure) light), and make one of the beams of light (the beam shown in the solid line in the figure) enter the beam combiner and splitter through the delay lens, and make the other beam of light (the beam shown in the dotted line in the figure) beam) directly into the beam combiner and splitter. The beam combiner and splitter are used to combine the two beams of light to obtain a second optical signal, and input the second optical signal into the optical fiber to be tested. Wherein, the second optical signal is formed by coupling two light beams with different optical paths.

In the backhaul direction (that is, from the optical fiber to be tested to the detection device), the beam combiner and splitter are used to split the third optical signal from the optical fiber to be tested to obtain two beams of light (indicated by dashed lines and solid lines in the figure). two beams). And let one beam of light (the beam shown by the dotted line in the figure) enter the beam splitter through the delay lens, and make the other beam of light (the beam shown by the solid line in the figure) directly enter the beam splitter device. The beam splitter is used to project the two light beams to the photodetector 2400 through the mirror to obtain a first feedback signal. Wherein, the first feedback signal is formed by coupling two beams with the same optical path (ie, the solid line beam and the dotted line beam in the figure).

In the embodiment of the present application, the time-delay lens has a simple structure and a small volume, which can reduce the volume of the detection device or the entire detection system.

It should be noted that the structure of the light source assembly 2100 in FIG. 7 is only an example, and does not limit the structure of the light source assembly 2100 .

In the structure in which the delay optical path 2210 includes a delay lens, the delay optical path can also be placed outside the detection device 2000 .

2.4. The delay optical path includes a delay lens, and the delay optical path is external.

As shown in FIG. 8 , the delay optical path (sagnac interferometer) structure including a delay lens, and the optical path under this structure, refer to the description in FIG. 7 , and will not be repeated here.

For the beneficial effect of placing the delay optical path externally, refer to the description of FIG. 6 , which will not be repeated here.

It should be noted that the structures including the delay lens or the delay optical fiber shown in FIG. 5 to FIG. 8 are only examples of the delay optical path, and do not limit the delay optical path. For example, the time-delay lens in FIG. 7 or FIG. 8 may also be replaced by a mirror group, which is not limited here.

Optionally, the detecting device 2000 provided in the embodiment of the present application may not only be used to detect the vibration state of the optical fiber, but also be used to detect the quality of the optical fiber.

3. Detection equipment that can detect the vibration state of optical fiber and the quality of optical fiber.

As shown in FIG. 9, the light source assembly 2100 may also include a burst LDD 2140. The burst LDD 2140 is used to obtain a square-wave electrical pulse signal, and the laser 2120 can obtain a square-wave optical pulse signal according to the square-wave electrical pulse signal. The square wave optical pulse signal is used to input the optical fiber to be tested to detect the quality of the optical fiber. In the embodiment of the present application, the square-wave optical pulse signal may also be referred to as an optical time-domain reflectometer (OTDR) signal.

Optionally, the above-mentioned structure including the continuous LDD 2111, the burst LDD 2140 and the laser 2120 is only an implementation for obtaining the first optical signal and the OTDR signal, and the light source assembly 2100 may also include the laser 2120, the modulation device 2130 and the burst LDD 2140. Wherein the laser 2120 and the modulation device 2130 are used to obtain the first optical signal, and the burst LDD 2140 and the laser are used to obtain the OTDR signal.

In the embodiment of the present application, the detection of the vibration state of the optical fiber and the detection of the quality of the optical fiber can be implemented on the same detection device in a time-division multiplexing manner. The time-division multiplexing of the two detections is realized through the architecture shown in FIG. 9 .

As shown in FIG. 9 , in this architecture, two optical switches may be included between the detection device 2000 and the optical fiber to be tested, for switching between the delayed optical path and the common optical fiber. When detecting the quality of the optical fiber, the detection device 2000 is connected to the optical fiber to be tested through the ordinary optical fiber to realize the detection of the optical fiber quality. When detecting the vibration state of the optical fiber, the delay optical path is connected, so that the detection device 2000 is connected to the optical fiber to be tested through the delay optical path, so as to realize the detection of the optical fiber vibration state.

The structure shown in FIG. 9 is a structure with an external delay optical path. Optionally, in the structure with a built-in delay optical path, the detection device 2000 may include a structure between the above two optical switches to realize switching between two types of detection (mass detection and vibration state detection).

As shown in FIG. 9 , two photodetectors 2400 and two computing units 2300 may be included in the backhaul direction (that is, the direction from the optical fiber to be tested to the detection device 2000 ). One of the photodetectors 2400 is used to receive the second feedback signal of the square wave optical pulse signal in the optical fiber to be tested, and convert the second feedback signal into an electrical signal and input it to a computing unit 2300 . The calculation unit 2300 is used to determine the quality of the optical fiber to be tested according to the electrical signal corresponding to the second feedback signal.

The other photodetector 2400 is used to receive the first feedback signal from the delay optical path, and convert the first feedback signal into an electrical signal and input it to another calculation unit 2300 . The calculating unit 2300 is used for determining the vibration state of the optical fiber to be tested according to the electrical signal corresponding to the first feedback signal.

Optionally, the detection device 2000 may also include only one photodetector 2400 to realize the photoelectric conversion of the first feedback signal and the second feedback signal. Optionally, the detection device 2000 may also include only one calculation unit 2300 to realize the detection of the quality of the optical fiber and the vibration state of the optical fiber.

Optionally, the application architecture of the detection device 2000 may also be as shown in FIG. 10 . Wherein the modulation circuit can be used to obtain a modulated electrical signal or a square electrical pulse signal, and input the modulated electrical signal or a square electrical pulse signal into the originating light source. That is, the modulation circuit here is equivalent to the integration of continuous LDD 2111 and burst LDD 2140 in the implementation example of FIG. 9 .

The originating light source is used to obtain the first optical signal according to the modulated electrical signal, or used to obtain the OTDR signal according to the square electrical pulse signal. That is, the originating light source here corresponds to the laser 2120 shown in FIG. 9 .

The source light source can be integrated with an avalanche photodiode (APD). The APD here is used to receive the second feedback signal (the feedback signal of the OTDR signal in the optical fiber to be tested), which is equivalent to a photodetector 2400 shown in FIG. 9 .

The photodetector in Figure 10 is connected to the coupler for receiving the first feedback signal (obtained through the delayed optical path, the feedback signal of the first optical signal in the optical fiber to be tested), which is equivalent to another photodetection in Figure 9 device 2400.

The structure of the detection device provided by the embodiment of the present application is described above, and the optical fiber detection method provided by the embodiment of the present application based on the detection device is described below.

See Figure 11, the method includes:

1101. The detection device acquires a first optical signal, where the first optical signal is a modulated single-channel wavelength signal.

Optionally, the detection device may acquire the first optical signal through optical modulation or electrical modulation. For details, refer to the descriptions in FIG. 3 and FIG. 4 , which will not be repeated here.

1102. The detecting device acquires a first feedback signal of the optical fiber to be tested obtained by passing the first optical signal through a delayed optical path.

In the embodiment of the present application, the delay optical path may be built in or external to the detection device 2000 . In the case where the delay optical path is built-in or external, the process of the detection device 2000 acquiring the first feedback signal refers to the descriptions in FIG. 5 to FIG. 8 , which will not be repeated here.

1103. The detection device determines the vibration state of the optical fiber to be tested according to the first feedback signal.

The detection device 2000 may acquire a waveform diagram of the feedback signal according to the received first feedback signal. Based on the waveform diagram, the vibration state of the optical fiber under test can be determined. Refer to the description of FIG. 1c for the specific process, which will not be repeated here.

In an optional implementation manner, the process of the detecting device 2000 acquiring the first optical signal may specifically include: the detecting device 2000 acquiring the modulated electrical signal; and the detecting device 2000 generating the first optical signal according to the modulated electrical signal.

In an optional implementation manner, the process for the detection device 2000 to obtain the first optical signal may specifically include: the detection device 2000 obtains a light beam with a single-channel wavelength; the detection device 2000 modulates the light beam with a single-channel wavelength to obtain the first optical signal .

In an optional implementation manner, the detection device 2000 modulates a single-channel wavelength light beam to obtain the first optical signal, which may specifically include: performing phase modulation, amplitude modulation or frequency modulation on the single-channel wavelength light beam, Obtain the first optical signal.

In an optional implementation manner, the process of the detecting device 2000 acquiring the first optical signal may specifically include: the detecting device 2000 acquiring the first optical signal with a rate greater than or equal to 155 Mbit/s.

In an optional implementation manner, the process in which the detecting device 2000 obtains the first feedback signal of the optical fiber under test obtained by passing the first optical signal through a delayed optical path may specifically include: the detecting device 2000 adjusts at least one path of the first optical signal The optical path of the light, to obtain the second optical signal, the second optical signal is formed by coupling two optical signals with different optical paths; the detection device 2000 inputs the second optical signal into the optical fiber to be tested, and obtains the third optical signal; the detection device 2000 The optical path of at least one path of light in the third optical signal is adjusted to obtain a first feedback signal, and the first feedback signal is formed by coupling two paths of optical signals with the same optical path.

In an optional implementation manner, the process of the detecting device 2000 obtaining the first feedback signal of the optical fiber under test obtained by passing the first optical signal through the delay optical path may specifically include: the detecting device 2000 inputs the first optical signal into the delay optical path, The delay optical path is used to input the second optical signal obtained based on the first optical signal into the optical fiber to be tested to obtain the third optical signal; wherein, the second optical signal is formed by coupling two optical signals with different optical paths; the detecting device 2000 receives The first feedback signal from the delayed optical path is obtained by adjusting the optical path of at least one path of light in the third optical signal by the optical fiber to be tested, and the first feedback signal is formed by coupling two paths of optical signals with the same optical path.

In an optional implementation manner, the delay optical path includes a delay lens and/or two optical fibers with different optical paths.

In an optional implementation manner, the process of the detection device 2000 inputting the first optical signal into the delay optical path may specifically include: the detection device 2000 inputs the first optical signal into the delay optical path, and at the same time connects the service signal input to the optical fiber to be tested The target optical fiber; the second optical signal obtained by adjusting the optical path of the first optical signal by the delay optical path and the service signal are simultaneously transmitted in the optical fiber to be tested.

In an optional embodiment, the optical fiber detection method further includes: the detection device 2000 excites the laser to obtain a square-wave optical pulse signal; the detection device 2000 sends a square-wave optical pulse signal to the optical fiber to be tested; A second feedback signal in the optical fiber; the detecting device 2000 determines the link quality of the optical fiber to be tested according to the second feedback signal.

In an optional implementation manner, the detecting device 2000 sends a square-wave optical pulse signal to the optical fiber to be tested at the first moment; the detecting device 2000 sends the first optical signal to the delay optical path at the second moment; or, the detecting device 2000 At a second moment, a second optical signal is sent to the optical fiber to be tested, and the second optical signal is obtained by adjusting the optical path of the first optical signal by the delay optical path.

The beneficial effects of the optical fiber detection method shown in FIG. 11 and the beneficial effects of the optional implementation of the method refer to the aforementioned FIGS. 2 to 10 , which will not be repeated here.

Those skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the above-described system, device and unit can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or May be integrated into another system, or some features may be ignored, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

If the integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium , including several instructions to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (read-only memory, ROM), random access memory (random access memory, RAM), magnetic disk or optical disc and other media that can store program codes. .

Claims

A detection device, characterized in that it comprises:

A light source component, configured to acquire a first optical signal, where the first optical signal is a modulated single-channel wavelength signal;

an optical path unit, configured to obtain a first feedback signal of the optical fiber to be tested obtained by delaying the first optical signal through an optical path;

A computing unit, configured to determine the vibration state of the optical fiber to be tested according to the first feedback signal.
The detection device according to claim 1, wherein the light source assembly comprises:

A laser drive circuit for obtaining a modulated electrical signal;

a laser, configured to generate the first optical signal according to the modulated electrical signal.
The detection device according to claim 2, wherein the laser drive circuit comprises:

A continuous laser modulator LDD, configured to drive the laser to generate the first optical signal according to the modulated electrical signal.
The detecting device according to claim 2 or 3, wherein the modulated electrical signal comprises a phase modulated signal, an amplitude modulated signal or a frequency modulated signal.
The detection device according to claim 1, wherein the light source assembly comprises:

a laser for obtaining a beam of light of a single channel wavelength;

A modulating device, configured to modulate the light beam of the single-channel wavelength to obtain the first optical signal.
The detection device according to claim 5, wherein the modulation device comprises:

Semiconductor optical amplifier SOA modulator or lithium niobate phase modulator.
The detecting device according to claim 5 or 6, wherein the modulation device is specifically used for:

performing phase modulation, amplitude modulation, or frequency modulation on the light beam of the single-channel wavelength to obtain the first optical signal.
The detection device according to any one of claims 1 to 7, wherein the light source assembly is specifically used for:

Acquire the first optical signal with a rate greater than or equal to 155 Mbit/s.
The detecting device according to any one of claims 1 to 8, wherein the optical path unit includes the delayed optical path, and the delayed optical path is used for:

adjusting the optical path of at least one path of light in the first optical signal to obtain a second optical signal, wherein the second optical signal is formed by coupling two paths of optical signals with different optical paths;

inputting the second optical signal into the optical fiber to be tested to obtain a third optical signal;

The optical path of at least one path of light in the third optical signal is adjusted to obtain the first feedback signal, and the first feedback signal is formed by coupling two paths of optical signals with the same optical path.
The detection device according to any one of claims 1 to 8, wherein the optical path unit is specifically used for:

The first optical signal is input into a delay optical path, and the delay optical path is used to input a second optical signal obtained based on the first optical signal into the optical fiber under test to obtain a third optical signal; wherein the second optical signal It is formed by coupling two optical signals with different optical paths;

receiving the first feedback signal from the delayed optical path, the first feedback signal is obtained by adjusting the optical path of at least one of the third optical signals in the optical fiber under test, and the first feedback signal is obtained by It is formed by coupling two optical signals with the same optical path.
The detecting device according to claim 9 or 10, characterized in that the delay optical path comprises at least one of a delay lens, a mirror group, and two optical fibers with different optical lengths.
The detection device according to any one of claims 1 to 11, wherein the optical path unit is specifically used for:

input the first optical signal into the delay optical path, and at the same time input the service signal into the target optical fiber connected to the optical fiber to be tested; The signal and the service signal are simultaneously transmitted in the optical fiber to be tested.
The detecting device according to any one of claims 2 to 12, characterized in that,

The light source assembly also includes a burst laser driver LDD, which is used to excite the laser to obtain a square-wave optical pulse signal;

The optical path unit is further configured to send the square-wave optical pulse signal to the optical fiber to be tested; and receive a second feedback signal of the square-wave optical pulse signal in the optical fiber to be tested;

The computing unit is further configured to determine the link quality of the optical fiber under test according to the second feedback signal.
The detection device according to claim 13, wherein the optical path unit is specifically used for:

At a first moment, sending the square wave optical pulse signal to the optical fiber to be tested;

At the second moment, sending the first optical signal to the delayed optical path; or, at the second moment, sending the second optical signal to the optical fiber under test, the second optical signal being the The delay optical path is obtained by adjusting the optical path of the first optical signal.
A kind of optical fiber detection method, is characterized in that, is applied to detection equipment, and described method comprises:

Acquiring a first optical signal, where the first optical signal is a modulated single-channel wavelength signal;

Obtaining a first feedback signal of the optical fiber under test obtained by passing the first optical signal through a delay optical path;

Determining the vibration state of the optical fiber under test according to the first feedback signal.