Optical fiber breakpoint detection device

Abstract

The invention provides an optical fiber breakpoint detection device. The device comprises a laser emitter used for generating a laser signal; the narrow-band light pass filter is used for filtering the laser signal generated by the laser transmitter; the light beam splitter is used for splitting the laser signal filtered by the narrow-band light pass filter; the optical circulator is used for inputting the detection optical signal into the to-be-detected optical fiber and receiving a comparison optical signal fed back by the to-be-detected optical fiber based on the detection light; the first photoelectric detector and the second photoelectric detector are used for converting optical signals into electric signals; the first comparator and the second comparator are used for processing the electric signals; and the processor is used for determining an open circuit detection result of the to-be-detected optical fiber through cross-correlation operation based on a processing result of the first comparator and a processing result of the second comparator. According to the scheme, the comparator is used for replacing an oscilloscope or a multi-bit analog-to-digital converter in the prior art for data sampling, so that the method is simpler and more flexible, is easy to integrate, and can adapt to more application scenes.

Description

Technical Field

[0001] The present disclosure relates to the technical field of optical fiber communication, and in particular to an optical fiber breakpoint detection device. Background Art

[0002] Optical Time-Domain Reflectometer (OTDR) is a device that measures optical fiber attenuation, connector loss, and fault location. It uses the backscattering and Fresnel reflection principles of light to obtain attenuation information from the backscattered light generated when light propagates in the optical fiber. Traditional OTDR is based on short optical pulses and cannot achieve high dynamic range and high spatial resolution at the same time. In contrast, single photon counting OTDR is a single photon detection based on time-correlated single photon counting technology. The detection process of this scheme is discrete, which can achieve ultra-high spatial resolution and high dynamic range, but it requires more integration time to obtain a complete signal, and the equipment cost is relatively high. Summary of the invention

[0003] The present disclosure aims to solve one of the technical problems in the related art at least to some extent.

[0004] To this end, an object of the present disclosure is to provide a fiber break detection device.

[0005] To achieve the above-mentioned purpose, the first aspect of the present disclosure proposes an optical fiber breakpoint detection device, including: a laser transmitter, a narrowband optical pass filter, an optical beam splitter, an optical circulator, a first photodetector, a second photodetector, a first comparator, a second comparator and a processor, wherein the laser transmitter is connected to the narrowband optical pass filter, the narrowband optical pass filter is connected to the optical beam splitter, the first output end of the optical beam splitter is connected to the first photodetector, the first photodetector is connected to the first comparator, the first comparator is connected to the processor, the second output end of the optical beam splitter is connected to the first end of the optical circulator, the second end of the optical circulator is connected to the optical fiber to be detected, the second photodetector is connected to the second comparator, and the second comparator is connected to the processor; wherein the laser transmitter is used to generate a laser signal ; The narrowband optical pass filter is used to filter the laser signal generated by the laser transmitter; the optical beam splitter is used to split the laser signal filtered by the narrowband optical pass filter to generate a reference optical signal and a detection optical signal; the optical circulator is used to input the detection optical signal into the optical fiber to be detected, and receive the comparison optical signal of the optical fiber to be detected based on the detection light feedback; the first photodetector is used to convert the reference optical signal into a reference electrical signal, and the second photodetector is used to convert the comparison optical signal into a comparison electrical signal; the first comparator is used to process the reference electrical signal, and the second comparator is used to process the comparison electrical signal; the processor is used to perform a cross-correlation operation based on the processing results of the first comparator and the processing results of the second comparator to determine the circuit breaker detection result of the optical fiber to be detected.

[0006] According to one embodiment of the present disclosure, the device also includes: an optical amplifier, which is arranged between the laser emitter and the narrow-band optical pass filter, and between the narrow-band optical pass filter and the optical beam splitter. The amplifier is used to amplify the laser signal generated by the laser emitter when the signal intensity of the laser signal generated by the laser emitter is less than a set value, and to amplify the laser signal filtered by the narrow-band optical pass filter.

[0007] According to one embodiment of the present disclosure, the device further includes: an optical isolator for isolating the reflected laser signal.

[0008] According to one embodiment of the present disclosure, the comparator is further used to: process the comparison electrical signal and the reference electrical signal, and use the comparison result as an input signal of a processor.

[0009] According to one embodiment of the present disclosure, the processor is further configured to: perform cross-correlation processing on the output time series of the first comparator and the second comparator to determine whether the optical fiber to be detected is broken.

[0010] According to one embodiment of the present disclosure, the processor is further configured to: when it is determined that the optical fiber to be detected is broken, determine the break position based on a cross-correlation operation result.

[0011] According to an embodiment of the present disclosure, the determining of the disconnection position based on the cross-correlation operation result includes: using the peak position of the cross-correlation operation result as the disconnection position.

[0012] According to one embodiment of the present disclosure, the laser emitter is a chaotic semiconductor laser.

[0013] According to one embodiment of the present disclosure, a comparison level is set for the first comparator and the second comparator.

[0014] According to one embodiment of the present disclosure, the device is further used to: compare the comparison electrical signal with the comparison level, and use the comparison result as an input signal of a processor.

[0015] In this solution, the comparator replaces the oscilloscope or multi-bit analog-to-digital converter used in the current technology for data sampling. It is simpler, more flexible, and easier to integrate. Compared with the current technology, it can adapt to more application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of an optical fiber break point detection device according to one embodiment of the present disclosure;

[0017] Figure 2 It is a structural schematic diagram of another optical fiber break point detection device according to an embodiment of the present disclosure;

[0018] Figure 3 It is a structural schematic diagram of another optical fiber break point detection device according to an embodiment of the present disclosure;

[0019] Figure 4 This is a spectrum diagram of the chaotic semiconductor laser output in an embodiment of the present invention.

[0020] Figure 5 This is a spectrum diagram of the chaotic semiconductor laser output in an embodiment of the present invention.

[0021] Figure 6 105 and 106 are time series respectively obtained by using an oscilloscope through the outputs of the first photodetector 105 and the second photodetector 106 in the embodiment of the present invention (the square □ and the circle ○ represent the reference light path and the return light path respectively).

[0022] Figure 7 ] are time series obtained through the outputs of the first comparator 107 and the second comparator 108 in the embodiment of the present invention (the square □ and the circle ○ represent the reference optical path and the return optical path respectively).

[0023] Figure 8 The cross-correlation curves are obtained by cross-correlation calculation using the oscilloscope solution and the solution of the embodiment of the present invention respectively. DETAILED DESCRIPTION

[0024] Embodiments of the present disclosure are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present disclosure, and should not be construed as limiting the present disclosure.

[0025] The acquisition, storage, use, and processing of data in the technical solution disclosed in this disclosure are in compliance with the relevant provisions of relevant laws and regulations.

[0026] It should be noted that in the embodiments of the present application, certain software, components, models and other existing solutions in the industry may be mentioned, and they should be considered as exemplary. Their purpose is only to illustrate the feasibility of implementing the technical solution of the present application, but it does not mean that the applicant has or will necessarily use the solution.

[0027] Figure 1 is a schematic diagram of the structure of an optical fiber break point detection device according to an embodiment of the present disclosure. Figure 1 As shown, the optical fiber breakpoint detection device includes: a laser transmitter 101, a narrowband optical filter 102, an optical beam splitter 103, an optical circulator 104, a first photodetector 105, a second photodetector 106, a first comparator 107, a second comparator 108 and a processor 109.

[0028] Among them, the laser emitter 101 is connected to the narrowband optical pass filter 102, the narrowband optical pass filter 102 is connected to the optical beam splitter 103, the first output end of the optical beam splitter 103 is connected to the first photodetector 105, the first photodetector 105 is connected to the first comparator 107, the first comparator 107 is connected to the processor 109, the second output end of the optical beam splitter 103 is connected to the first end of the optical circulator 104, the second end of the optical circulator 104 is connected to the optical fiber to be detected, the second photodetector 106 is connected to the second comparator 108, and the second comparator 108 is connected to the processor 109.

[0029] The laser transmitter 101 is used to generate a laser signal.

[0030] The narrowband optical pass filter 102 is used to filter the laser signal generated by the laser transmitter 101 .

[0031] The optical beam splitter 103 is used to split the laser signal filtered by the narrow-band optical pass filter 102 to generate a reference optical signal and a detection optical signal.

[0032] The optical circulator 104 is used to input the detection optical signal into the optical fiber to be detected, and receive the comparison optical signal of the optical fiber to be detected based on the detection light feedback.

[0033] The first photodetector 105 is used to convert the reference optical signal into a reference electrical signal, and the second photodetector 106 is used to convert the comparison optical signal into a comparison electrical signal. It should be noted that the first photodetector 105 and the second photodetector 106 are also used to retain the AC signal through the DC blocking capacitor.

[0034] The first comparator 107 is used to process the reference electrical signal, and the second comparator 108 is used to process the comparison electrical signal.

[0035] It should be noted that the comparator in the embodiment of the present disclosure is an electronic circuit used to compare the magnitudes of two input voltages and output a high level or a low level according to the comparison result. The comparator is usually used to detect whether a signal exceeds a certain threshold or to compare two signals.

[0036] It should be noted that this solution replaces the current technology of using an oscilloscope or a multi-bit analog-to-digital converter for data sampling with a comparator, which is simpler, more flexible, and easier to integrate, and can adapt to more application scenarios compared to the current technology.

[0037] The processor 109 is used to perform a cross-correlation operation based on the processing result of the first comparator 107 and the processing result of the second comparator 108, and determine a disconnection detection result of the optical fiber to be detected according to the operation result.

[0038] In one possible implementation, Figure 2 As shown, the optical fiber break point detection device further includes an optical amplifier 201. The optical amplifier 201 is arranged between the laser emitter 101 and the narrow-band optical pass filter 102, and between the narrow-band optical pass filter 102 and the optical beam splitter 103. The amplifier is used to amplify the laser signal generated by the laser emitter 101 when the signal intensity of the laser signal generated by the laser emitter 101 is less than a set value, and to amplify the laser signal filtered by the narrow-band optical pass filter 102. In this way, the final detection result can be prevented from being affected by too low light intensity.

[0039] In one possible implementation, Figure 3As shown, the optical fiber break point detection device further includes an optical isolator 301 for isolating the reflected laser signal. The optical isolator 301 is arranged between the laser transmitter 101 and the narrow-band optical pass filter 102 .

[0040] It should be noted that the optical isolator 301 is used to feed back the light output by the laser to the laser, so as to avoid damage to the laser transmitter 101 .

[0041] In the embodiment of the present disclosure, the comparator is further used to: perform processing on the comparison electric signal and the reference electric signal.

[0042] The processor 109 is further configured to perform a cross-correlation operation on the outputs of the first comparator and the second comparator to determine whether a break occurs in the optical fiber to be detected.

[0043] It should be noted that, when it is determined that the optical fiber to be detected is broken, the break position is determined based on the cross-correlation calculation result.

[0044] In the embodiment of the present disclosure, the peak position of the cross-correlation curve may be used as the disconnection position.

[0045] In one embodiment of the present disclosure, the laser transmitter 101 is a chaotic semiconductor laser. It should be noted that chaotic semiconductor lasers are a promising fiber measurement technology. Broadband chaotic lasers with a delta-like autocorrelation function can overcome the trade-off between dynamic range and spatial resolution. Chaos-related OTDR has been studied using monolithic integrated feedback chaotic lasers and hybrid integrated short external cavity chaotic lasers. However, these chaotic semiconductor lasers with optical feedback will cause time delay characteristics of the autocorrelation curve of the time domain signal due to the feedback periodicity, which may interfere with the detection position. Recently, there have been reports of self-chaotic lasers realized by designing arc-edge polygonal microcavities based on internal mode interactions. The advantages of these solitary self-chaotic microcavity lasers are small geometric dimensions, no need for external optical feedback and light injection, and no delay periodicity, so that the self-chaotic microlasers can achieve robust chaotic operation in practical applications. As a result, the volume of the optical fiber breakpoint detection device can be further reduced.

[0046] In the disclosed embodiment, the chaotic semiconductor laser is a room temperature continuous electric injection laser, which is operated in a chaotic state by controlling the injection current to increase its frequency bandwidth.

[0047] In this embodiment, the substrate material of the chaotic semiconductor laser 101 is indium phosphide, and the active layer is an aluminum gallium indium arsenide multiple quantum well structure.

[0048] See also Figure 4, the output laser spectra of the chaotic semiconductor laser when the continuous injection current is 7mA, 9mA, and 16mA are given. It can be seen that when the injection current is 7mA, the laser output is a single-mode laser, when the injection current is 9mA, the laser is in a periodic oscillation state, and when the injection current is 16mA, the laser is in a chaotic output state.

[0049] See also Figure 5 , the output laser spectrum of the chaotic semiconductor laser when the continuous injection current is 9mA and 16mA is given. It can be seen that when the injection current is 9mA, there is an obvious peak at the frequency of 5.9GHz on the laser spectrum, indicating that the frequency of the laser is in periodic oscillation at 5.9GHz. When the injection current is 16mA, the laser spectrum has no obvious peak, indicating that the laser is in a chaotic state.

[0050] In the embodiment of the present disclosure, a comparison level may be set for the first comparator 107 and the second comparator 108 .

[0051] The corresponding time series can be obtained by comparing the comparison electrical signal with the comparison level.

[0052] In one possible implementation, Figure 6 As shown, when the laser emitter 101 is a chaotic semiconductor laser, the time series (the square □ and the circle ○ represent the reference optical path and the return optical path respectively) obtained by sampling the output of the first photodetector 105 and the second photodetector 106 using an oscilloscope is shown as a random signal.

[0053] In another possible implementation, when the test parameters and the test object are the same, such as Figure 7 As shown in FIG. 1 , it is a time series obtained by the output of the first comparator 107 and the second comparator 108 (the square □ and the circle ○ represent the reference light path and the return light path respectively). Figure 8 As shown, the oscilloscope solution and the comparator solution of the embodiment of the present invention are respectively used to obtain the cross-correlation curves through cross-correlation calculation. Figure 8 From the generated curve, it can be seen that compared with the current technology, this solution reduces the equipment size and cost without affecting the detection accuracy.

[0054] Based on the above analysis results, the scheme of obtaining time series using two oscilloscopes or dual-channel oscilloscopes can be simplified to a scheme of obtaining time series using a comparator, which can greatly simplify the equipment and reduce costs.

[0055] In the description of the aforementioned embodiments, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0056] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

Claims

1. An optical fiber breakpoint detection device, characterized in that: include: A laser transmitter, a narrow-band optical pass filter, an optical beam splitter, an optical circulator, a first photodetector, a second photodetector, a first comparator, a second comparator and a processor, wherein the laser transmitter is connected to the narrow-band optical pass filter, the narrow-band optical pass filter is connected to the optical beam splitter, a first output end of the optical beam splitter is connected to the first photodetector, the first photodetector is connected to the first comparator, the first comparator is connected to the processor, a second output end of the optical beam splitter is connected to a first end of the optical circulator, a second end of the optical circulator is connected to an optical fiber to be detected, the second photodetector is connected to the second comparator, and the second comparator is connected to the processor; Wherein, the laser transmitter is used to generate a laser signal; The narrowband optical pass filter is used to filter the laser signal generated by the laser transmitter; The optical beam splitter is used to split the laser signal filtered by the narrow-band optical pass filter to generate a reference optical signal and a detection optical signal; The optical circulator is used to input the detection optical signal into the optical fiber to be detected, and receive the comparison optical signal of the optical fiber to be detected based on the detection light feedback; The first photodetector is used to convert the reference optical signal into a reference electrical signal, and the second photodetector is used to convert the comparison optical signal into a comparison electrical signal; The first comparator is used to process the reference electrical signal, and the second comparator is used to process the comparison electrical signal; The processor is used for performing a cross-correlation operation based on a processing result of the first comparator and a processing result of the second comparator to determine a disconnection detection result of the optical fiber to be detected.

2. The optical fiber break point detection device according to claim 1, characterized in that: The device also includes: An optical amplifier is arranged between the laser emitter and the narrow-band optical pass filter, and between the narrow-band optical pass filter and the optical beam splitter. The amplifier is used to amplify the laser signal generated by the laser emitter when the signal intensity of the laser signal generated by the laser emitter is less than a set value, and to amplify the laser signal filtered by the narrow-band optical pass filter.

3. The optical fiber break point detection device according to claim 1, characterized in that: The device also includes: Optical isolator, used to isolate the reflected laser signal.

4. The optical fiber break point detection device according to claim 1, characterized in that: The comparator is also used to: The comparison electrical signal and the reference electrical signal are processed.

5. The optical fiber break point detection device according to claim 4, characterized in that: The processor is further configured to: A cross-correlation operation is performed on the output time series of the first comparator and the second comparator to determine whether the optical fiber to be detected is broken.

6. The optical fiber break point detection device according to claim 5, characterized in that: The processor is further configured to: When it is determined that the optical fiber to be detected is broken, the break position is determined based on the cross-correlation calculation result.

7. The optical fiber break point detection device according to claim 6, characterized in that: The determining of the disconnection position based on the cross-correlation operation result comprises: The peak position of the cross-correlation calculation result is used as the disconnection position.

8. The optical fiber break point detection device according to claim 1, characterized in that: The laser emitter is a chaotic semiconductor laser.

9. The optical fiber break point detection device according to claim 1, characterized in that: A comparison level is set for the first comparator and the second comparator.

10. The optical fiber break point detection device according to claim 1, characterized in that: The device is also used for: The comparison electric signal is compared with the comparison level, and the comparison result is used as an input signal of the processor.

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