CN109391322B - Device and method for measuring length of medium-short optical fiber jumper - Google Patents
Device and method for measuring length of medium-short optical fiber jumper Download PDFInfo
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- CN109391322B CN109391322B CN201811534185.9A CN201811534185A CN109391322B CN 109391322 B CN109391322 B CN 109391322B CN 201811534185 A CN201811534185 A CN 201811534185A CN 109391322 B CN109391322 B CN 109391322B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
- H04B10/071—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
- H04B10/075—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
- H04B10/077—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using a supervisory or additional signal
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
- H04B10/075—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
- H04B10/079—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
- H04B10/075—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
- H04B10/079—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
- H04B10/0791—Fault location on the transmission path
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/516—Details of coding or modulation
- H04B10/548—Phase or frequency modulation
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- Testing Of Optical Devices Or Fibers (AREA)
Abstract
The invention discloses a device and a method for measuring the length of a medium-short optical fiber jumper, wherein the device comprises: the visible light generating circuit is used for generating visible light signals, dividing the visible light signals into two paths of light signals and respectively outputting the two paths of light signals to the standard optical fiber jumper length measuring circuit and the measured optical fiber jumper length measuring circuit; the standard optical fiber jumper length measuring circuit is used for measuring an optical signal returned by the standard optical fiber jumper and converting the optical signal into an electric signal to be output to the modulation and demodulation circuit; the measured optical fiber jumper length measuring circuit is used for measuring an optical signal returned by the measured optical fiber jumper and converting the optical signal into an electric signal to be output to the modulation and demodulation circuit; and the modulation and demodulation circuit is used for modulating the frequency of the visible light signal generated by the visible light generating circuit, demodulating the received two electric signals and calculating the length of the tested optical fiber jumper.
Description
Technical Field
The disclosure belongs to the technical field of optical fiber sensing, and particularly relates to a middle-short light jumper device and method based on visible light phase modulation.
Background
In many high voltage electric field environments, equipment fails during medium and long distance transmission, and because optical fibers need to transmit optical signals, each optical fiber has to be measured by plugging in visible light.
On fiber optic measurements at long distances of 1-100 km, OTDR is used for the measurements. Many optical fiber jumpers are medium-short distance optical fiber jumpers, and optical fibers for transmitting various weak electric signals are multimode jumpers, and the length of the optical fiber jumpers is generally in the range of 1-1000 meters. When OTDR is adopted, the effective measurement advantage of the optical fiber jumper is lost when the optical fiber jumper is measured for 1-1000 meters. In the measurement of the OTDR, the resolution ratio is lower, and the positions between fault points are generally 3-5 meters to be resolved. In addition, when the optical fiber jumper is used, laser with the wavelength of 1310nm or 1550nm can pass through, and when the OTDR is used, the working wavelength of the OTDR is 1310nm or 1550nm, the wavelength of the measuring light source and the signal transmission wavelength are both in a communication band, and when the optical fiber jumper is measured on line, a filter is added at the tail end of the light, otherwise, whether the optical fiber jumper is on-line or not can not be measured on line in a single end mode. The OTDR function can measure the quality of the optical fiber, but cannot distinguish the on-off condition of the optical fiber jumper.
In summary, how to solve the problem of on-line measurement of the length of the optical fiber to distinguish the on-off of the optical fiber jumper by the medium-short distance ratio is not yet available.
Disclosure of Invention
Aiming at the on-off problem of the short and medium optical fiber jumpers in the online measurement in the existing OTDR technology, the present disclosure provides a device and a method for measuring the length of the short and medium optical fiber jumpers, which solve the on-off problem of the short and medium optical fiber jumpers in the online measurement.
The technical scheme adopted by the present disclosure is:
a medium and short optical fiber jumper length measuring device, the device comprising:
the visible light generating circuit is used for generating a visible light signal, dividing the visible light signal into two paths of light signals and respectively outputting the two paths of light signals to the standard optical fiber jumper length measuring circuit and the measured optical fiber jumper length measuring circuit;
the standard optical fiber jumper length measuring circuit is used for measuring an optical signal returned by the standard optical fiber jumper and converting the optical signal into an electric signal to be output to the modulation and demodulation circuit;
the measured optical fiber jumper length measuring circuit is used for measuring an optical signal returned by the measured optical fiber jumper and converting the optical signal into an electric signal to be output to the modulation and demodulation circuit;
the modulation and demodulation circuit is used for modulating the frequency of the visible light signal generated by the visible light generation circuit, demodulating the received two electric signals, respectively recording the same different frequency values of the optical signal returned by the standard optical fiber jumper and the same different frequency values of the optical signal returned by the tested optical fiber jumper, respectively calculating the same frequency difference value of the optical signal returned by the standard optical fiber jumper and the same frequency difference value of the optical signal returned by the tested optical fiber jumper, and calculating the length of the tested optical fiber jumper according to the length of the standard optical fiber jumper.
Further, the visible light generating circuit comprises a visible light laser and a first coupler, and the visible light laser outputs a visible light signal to the first coupler; the first coupler divides the received visible light signal into two paths of light signals, one path of light signal is output to the standard optical fiber jumper length measuring circuit, and the other path of light signal is output to the measured optical fiber jumper length measuring circuit.
Further, the standard optical fiber jumper length measuring circuit comprises a second coupler and a first photoelectric detector, wherein the second coupler receives one path of optical signals output by the first coupler and outputs the optical signals to the standard optical fiber jumper, the optical signals are reflected back to the second coupler through the end face of the standard optical fiber jumper, the second coupler transmits the optical signals returned by the standard optical fiber jumper to the first photoelectric detector, and the first photoelectric detector converts the received optical signals into electric signals and outputs the electric signals to the modulation-demodulation circuit.
Further, the measured optical fiber jumper length measuring circuit comprises a third coupler and a second photoelectric detector, wherein the third coupler receives the other path of optical signal output by the first coupler and outputs the other path of optical signal to the measured optical fiber jumper, the optical signal is reflected back to the third coupler through the end face of the measured optical fiber jumper, the third coupler transmits the optical signal returned by the measured optical fiber jumper to the second photoelectric detector, and the second photoelectric detector converts the received optical signal into an electric signal and outputs the electric signal to the modulation and demodulation circuit.
Further, the modulation and demodulation circuit comprises a modulation circuit, a standard optical fiber optical signal demodulation circuit and a tested optical fiber optical signal demodulation circuit;
the modulating circuit comprises a central processing unit, a signal generator and a laser driver which are sequentially connected, wherein the central processing unit modulates the optical signals of the visible light laser through the signal generator and the laser driver;
the standard optical fiber optical signal demodulation circuit comprises a first photodiode, a first signal amplifier and a first phase comparator which are sequentially connected, wherein the first photodiode receives an optical signal returned by a standard length optical fiber jumper wire measured by the first photoelectric detector, the optical signal is amplified by the first signal amplifier and then is output to the first phase comparator, the first phase comparator compares the amplified optical signal with an original sine wave signal of the signal generator, and the comparison result is output to the central processor;
the optical signal demodulation circuit of the tested optical fiber comprises a second photodiode, a second signal amplifier and a second phase comparator which are sequentially connected, wherein the second photodiode receives an optical signal returned by a tested optical fiber jumper wire measured by the second photoelectric detector, the optical signal is amplified by the second signal amplifier and then is output to the second phase comparator, the second phase comparator compares the amplified optical signal with an original sine wave signal of the signal generator, and a comparison result is output to the central processor.
The method for measuring the length of the medium-short optical fiber jumper is realized based on the medium-short optical fiber jumper length measuring device, and comprises the following steps:
the method comprises the steps of obtaining the modulation frequency of a visible light signal, and respectively calculating the power of an optical signal returned by a standard length optical fiber jumper and a tested optical fiber jumper;
respectively calculating the same adjacent frequency difference value of the optical signals returned by the standard length optical fiber jumper and the tested optical fiber jumper;
calculating the length of the tested optical fiber jumper by using the obtained adjacent frequency difference value;
and comparing the initial value of the length of the detected optical fiber jumper with the obtained length of the detected optical fiber jumper, and identifying the on-off condition of the detected optical fiber jumper.
Further, the calculation method of the optical signal power returned by the standard length optical fiber jumper and the tested optical fiber jumper comprises the following steps:
acquiring the initial frequency, the modulation speed and the working time of the visible light signal, and calculating the modulation frequency of the visible light signal at any moment;
calculating the power of the optical signal reflected back by the standard optical fiber jumper wire by utilizing the modulation frequency of the visible light signal;
and calculating the power of the optical signal reflected back by the tested optical fiber jumper wire by utilizing the modulation frequency of the visible light signal.
Further, the calculation method of the adjacent frequency difference value of the same phase of the optical signal returned by the standard length optical fiber jumper and the tested optical fiber jumper is as follows:
recording different frequency values of the optical signals when the phase values of the optical signals returned by the standard optical fiber jumper are the same according to the optical signal power reflected by the standard optical fiber jumper, and differencing the recorded different frequency values of the optical signals to obtain the adjacent frequency difference value when the phase of the optical signals returned by the standard optical fiber jumper is the same;
and recording different frequency values of the optical signals when the power phase values of the optical signals returned by the tested optical fiber jumper are the same according to the power of the optical signals reflected by the tested optical fiber jumper, and differencing the recorded different frequency values of the optical signals to obtain the difference value between adjacent frequencies when the phases of the optical signals returned by the tested optical fiber jumper are the same.
Further, the method for calculating the length of the tested optical fiber jumper wire comprises the following steps:
calculating the ratio of the adjacent frequency difference value of the same phase of the optical signal returned by the standard optical fiber jumper to the adjacent frequency difference value of the same phase of the optical signal returned by the tested optical fiber jumper, and multiplying the obtained ratio by the length of the standard optical fiber jumper to obtain the length of the tested optical fiber jumper.
Further, the step of identifying the on-off condition of the tested optical fiber jumper comprises the following steps:
comparing the initial value of the length of the tested optical fiber jumper with the obtained measured value of the length of the tested optical fiber jumper;
if the initial value of the length of the tested optical fiber jumper is equal to the obtained measured value of the length of the tested optical fiber jumper, the tested optical fiber jumper is light-transmitting;
if the initial value of the length of the detected optical fiber jumper is unequal to the obtained measured value of the length of the detected optical fiber jumper, the detected optical fiber jumper is cut off.
Through foretell technical scheme, the beneficial effect of this disclosure is:
(1) The method adopts a phase modulation method, and the length measurement precision of the middle-short optical fiber can be improved by modulating the accurate frequency resolution;
(2) The optical fiber jumper measuring device adopts a double-optical-path structure, the length of the standard length optical fiber can be changed, the measurement of the middle-short distance optical fiber jumper can be realized, and the measurement precision of the middle-short optical fiber jumper is improved;
(3) The modulation and demodulation circuit is adopted to modulate the visible light laser, so that the induction wavelength of the original 1310nm or 1550nm InGaAs photoelectric probe can be effectively avoided, and the length measurement of the optical fiber jumper can be realized;
(4) The invention adopts the modulation and demodulation circuit to modulate the frequency of the visible light laser, respectively measures the optical signals returned by the standard length optical fiber jumper and the measured optical fiber jumper, calculates the length of the middle-short distance optical fiber jumper by the adjacent frequency difference value when the two optical paths are in the same phase, has small modulation frequency range and can realize the accurate measurement of the middle-short distance optical fiber jumper.
Drawings
The accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate and explain the exemplary embodiments of the disclosure and together with the description serve to explain the disclosure, and do not constitute an undue limitation on the disclosure.
FIG. 1 is a block diagram of a medium and short fiber jumper length measuring device;
fig. 2 is a block diagram of a modem circuit.
Detailed Description
It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments in accordance with the present disclosure. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.
One or more embodiments provide a medium-short optical fiber jumper length measuring device, which comprises a visible light generating circuit, a standard optical fiber jumper length measuring circuit, a measured optical fiber jumper length measuring circuit and a modulation-demodulation circuit.
Fig. 1 is a schematic structural diagram of a medium-short optical fiber jumper length measuring device. As shown in fig. 1, the visible light generating circuit includes a visible light laser 1 and a first coupler 2, wherein an output end of the visible light laser 1 is connected to an input end of the first coupler 2, and is used for outputting a visible light signal to the first coupler 2; the first coupler 2 is configured to divide the received visible light signal into two paths of light signals, one path of light signal is output to the standard optical fiber jumper length measurement circuit, the light signal returned by the standard optical fiber jumper is measured, and the other path of light signal is output to the measured optical fiber jumper length measurement circuit, and the light signal returned by the measured optical fiber jumper is measured.
The standard optical fiber jumper length measuring circuit comprises a second coupler 3 and a first photoelectric detector 7, wherein the input end of the second coupler 3 is connected with an optical path output end of the first coupler 2, one optical path output end of the second coupler 3 is connected with the standard length optical fiber jumper 5, the other optical path output end is connected with the first photoelectric detector 7, one path of light output by the first coupler is output to the standard length optical fiber jumper through the second coupler 3, the path of light is fresnel-reflected into the second coupler 3 through the end face of the standard length optical fiber jumper, the second coupler 3 transmits an optical signal reflected back by the standard length optical fiber jumper to the first photoelectric detector 7, and the first photoelectric detector 7 converts the received optical signal into an electric signal and outputs the electric signal to the modulation-demodulation circuit.
The measured optical fiber jumper length measuring circuit comprises a third coupler 4 and a second photoelectric detector 8, wherein the input end of the third coupler 4 is connected with the other optical path output end of the first coupler 2, one optical path output end of the third coupler 4 is connected with the measured optical fiber jumper 6, the other optical path output end is connected with the second photoelectric detector 8, the other path of light output by the first coupler is output to the measured optical fiber jumper through the third coupler 4, the path of light is reflected into the third coupler 4 through the end face Fresnel of the measured optical fiber jumper, the third coupler 4 transmits the optical signal reflected back by the measured optical fiber jumper to the second photoelectric detector 8, and the second photoelectric detector 8 converts the received optical signal into an electric signal and outputs the electric signal to the modulation and demodulation circuit.
The modulation and demodulation circuit is respectively connected with the output ends of the first photoelectric detector 7 and the second photoelectric detector 8, receives the electric signals output by the first photoelectric detector 7 and the second photoelectric detector 8, respectively demodulates the electric signals to obtain the optical signal power returned by the standard-length optical fiber jumper and the optical signal power returned by the tested optical fiber jumper, is also connected with the visible light laser 1, modulates the frequency of the visible light signal, calculates the adjacent frequency difference value when the optical signal power phase returned by the standard-length optical fiber jumper is the same as the adjacent frequency difference value when the optical signal power phase returned by the tested optical fiber jumper, and calculates the length of the tested optical fiber jumper according to the length of the standard optical fiber jumper.
In the modulation circuit, a plurality of optical signals with the same power phase are generated in the process of frequency from low frequency to high frequency. The modulation-demodulation circuit calculates adjacent frequency difference through different frequency values of the same value of the power phase of the optical signal, and finally calculates the length of the tested optical fiber jumper through the length of the standard optical fiber jumper.
As shown in fig. 2, the modulation and demodulation circuit includes a modulation circuit and an optical signal demodulation circuit, wherein:
the modulation circuit comprises a central processing unit 10, a signal generator 11 and a laser driver 12, wherein the central processing unit 10 is sequentially connected with the signal generator 11 and the laser driver 12, and the output end of the laser driver 12 is connected with the visible light laser 1.
The central processing unit 10 outputs a frequency increasing signal to the signal generator 12 according to clock stepping, the frequency of the sinusoidal signal sent by the signal generator 2 is changed, the changed sinusoidal signal is output to the laser driver 12, the current signal of the laser driver 12 is changed, the changed current signal is output to the visible light laser 1, and finally the light intensity change of the visible light laser 1 is changed, so that the light power signal of the visible light laser 1 is output according to a sinusoidal signal.
The optical signal demodulation circuit includes a first photodiode 13, a second photodiode 14, a first signal amplifier 15, a second signal amplifier 16, a first phase comparator 17, a second phase comparator 18, a central processor 10, and a signal generator 11; the input end of the first photodiode 13 is connected with the first photoelectric detector 7, the output end of the first photodiode 13 is connected with the first signal amplifier 15, the output end of the first signal amplifier 15 is connected with the first phase comparator 17, the first phase comparator 17 is also connected with the signal generator 11, and the output end of the first phase comparator 17 is connected with the central processor 10; the output end of the second photodiode 14 is connected with the second photodetector 8, the output end of the second photodiode 14 is connected with the second signal amplifier 16, the output end of the second signal amplifier 16 is connected with the second phase comparator 18, the second phase comparator 18 is also connected with the signal generator 11, and the output end of the second phase comparator 18 is connected with the central processor 10.
The first photodiode 13 receives the optical signal returned by the standard length optical fiber jumper measured by the first photodetector 7, the optical signal is amplified proportionally by the first signal amplifier 15, the amplified signal is compared with the original sine wave signal of the signal generator 11 by the first phase comparator 17, and the result of the phase comparison by the first phase comparator 17 is input into the central processing unit 10; the second photodiode 14 receives the optical signal returned by the optical fiber jumper to be measured and measured by the second photodetector 8, the optical signal is subjected to proportional amplification by the second signal amplifier 16, the amplified signal is compared with the original sine wave signal of the signal generator 11 by the second phase comparator 18, and the result of the phase comparison by the second phase comparator 18 is input into the central processing unit 10; when the phases in the adjacent two first phase comparators are the same, the two frequency values are recorded respectively, and when the phases in the adjacent two second phase comparators are the same, the two frequency values are recorded respectively, and the length of the tested optical fiber is calculated according to the frequency difference ratio of the two times and the length of the standard optical fiber jumper.
In this embodiment, the central processor may use a DSP processing module or an FPGA processing module.
The working principle of the medium-short optical fiber jumper length measuring device provided by the embodiment is as follows:
the visible light laser 1 outputs visible light signals with adjustable phases, two paths of optical signals are separated after the visible light signals pass through the first coupler 2, one path of optical signals are output to the second coupler 3 and output to the standard length optical fiber jumper 5 through the second coupler 3, the optical signals are Fresnel-reflected from the end face of the standard length optical fiber jumper to the second coupler 3 and then transmitted to the first photoelectric detector 7 through the second coupler 3, and the first photoelectric detector 7 outputs electric signals to the modulation and demodulation circuit for demodulation; the other path of optical signals are output to the third coupler 4, are output to the tested optical fiber jumper 6 through the third coupler 4, are fresnel reflected from the end face of the tested optical fiber jumper 6 to the third coupler 4, are transmitted to the second photoelectric detector 8 through the third coupler 4, and are demodulated after the second photoelectric detector 8 outputs electric signals to the modulation and demodulation circuit, and the tested optical fiber jumper length is obtained through the modulation and demodulation circuit.
The standard optical fiber jumper length measuring circuit and the measured optical fiber jumper length measuring circuit are adopted, when the measured optical fiber jumper is connected, the lengths of the standard optical fiber jumper and the measured optical fiber jumper are measured by modulating the frequency of a visible light signal output by a visible light laser, and when the power phase of an optical signal reflected by the standard optical fiber jumper or the power phase of an optical signal reflected by the measured optical fiber jumper is the same, different frequency values of the optical signal are recorded by the modulation and demodulation circuit; and calculating adjacent frequency differences through different frequency values of the same value of the power phase of the optical signal, and finally calculating the length of the tested optical fiber jumper through the length of the standard optical fiber jumper.
In the embodiment, the length of the optical fiber jumper is measured by adopting the visible light signal, so that the influence of visible light on the photoelectric detector of 1310 or 1550 wave bands is effectively avoided, and a filter is not required to be added at the other end of the optical fiber jumper; in addition, the frequency range of the frequency of the modulated visible light signal can be greatly reduced by referring to the optical fiber jumper with standard length, a modulation and demodulation circuit is simplified, and the length measurement of the middle-short optical fiber jumper is realized.
One or more embodiments further provide a method for measuring the length of a medium-short optical fiber jumper, which is implemented based on the medium-short optical fiber jumper length measuring device, and comprises the following steps:
s101, respectively calculating the power of the optical signal reflected by the standard length optical fiber jumper and the power of the optical signal reflected by the tested optical fiber jumper.
The specific implementation manner of the step 101 is as follows:
s101-1, obtaining the initial frequency f of a visible light signal output by a visible light laser 0 And calculating the modulation frequency of the visible light signal according to the modulation speed and the working time.
In the embodiment, the phase modulation frequency of the visible light signal output by the visible light laser is linearly changed, and the initial frequency is f 0 The method comprises the steps of carrying out a first treatment on the surface of the Frequency modulation speed k 1 Hz/s, the modulation frequency f (t) of the visible light signal output by the visible light laser at time t is:
f(t)＝f 0 +k 1 *t(1)。
s101-2, calculating the power I of an optical signal reflected by a path of optical signal output by the first coupler 2 through a standard length optical fiber jumper 1 。
Optical signal power I output by a first photodetector for measuring the frequency of an optical signal reflected back by a standard length optical fiber jumper 1 The method comprises the following steps:
I 1 ＝I 0 *Cos[2*π*f(t)*L 1 /(n*c)](2)
wherein I is 0 Is constant, f (t) is the visible light signal output by the visible light laser at tModulation frequency of time, L 1 The length of the optical fiber jumper is the standard length, n is the refractive index, and C is the light speed.
S101-3, calculating the power I of the optical signal reflected by the other path of optical signal output by the first coupler 2 through the tested optical fiber jumper 2 。
Optical signal power I output by a second photoelectric detector for measuring optical signal frequency reflected back by tested optical fiber jumper 2 The method comprises the following steps:
I 2 ＝I 0 *Cos[2*π*f(t)*L 2 /(n*c)](3)
wherein I is 0 Is constant, f (t) is the modulation frequency of the visible light signal output by the visible light laser at t time, L 2 And n is the refractive index, and C is the light speed for the length of the optical fiber jumper to be tested.
S102, calculating adjacent frequency difference values when the optical signals reflected by the optical fiber jumpers with standard lengths are in the same phase, and calculating adjacent frequency difference values when the optical signals reflected by the tested optical fiber jumpers are in the same phase.
S102-1, calculating adjacent frequency difference values when the power of the optical signals reflected by the optical fiber jumpers with the standard lengths is the same in phase.
Initializing the system, the length of the standard length optical fiber jumper is fixed and known, assuming t=t 1 And t=t 2 At the moment, the phase values of the optical signal power reflected by the standard length optical fiber jumper are the same, and t=t is recorded 1 And t=t 2 Modulation frequency value f (t 1 ) And f (t) 2 ) The following formula can be obtained:
2*π*f(t 1 )*L 1 /(n*c)+2*π＝2*πf(t 2 )*L1/(n*c)(4)，
then the adjacent frequency differences deltaf 1 Is that
Δf 1 ＝f(t 2 )-f(t 1 )＝(n*c)/L 1 (5)
Wherein f (t) 1 ) The visible light signal output by the visible light laser is at t 1 The modulation frequency of the moment, f (t 2 ) The visible light signal output by the visible light laser is at t 2 Modulation frequency of time, L 1 The length of the optical fiber jumper is the standard length, n is the refractive index, and C is the light speed.
S102-2, calculating adjacent frequency difference values when the optical signals reflected by the tested optical fiber jumpers are in the same phase.
When t=t 3 And t=t 4 At the moment, the phase values of the optical signals reflected by the tested optical fiber jumpers are equal, and t 3 ，t 4 The phase values of the optical signals reflected by the tested optical fiber jumpers are not equal between the moments, and the modulation frequency value f (t 3 ) And f (t) 4 ) The following formula can be obtained:
2*π*f(t 3 )*L 2 /(n*c)+2*π＝2*π*f(t 4 )*L2/(n*c)(6)
when the phases are the same, the adjacent frequency difference is Deltaf 2 I.e.
Δf 2 ＝f(t 4 )-f(t 3 )＝(n*c)/L 2 (7)
Wherein f (t) 3 ) The visible light signal output by the visible light laser is at t 3 The modulation frequency of the moment, f (t 4 ) The visible light signal output by the visible light laser is at t 4 Modulation frequency of time, L 2 And n is the refractive index, and C is the light speed for the length of the optical fiber jumper to be tested.
S103, calculating the length of the tested optical fiber jumper.
And (3) calculating the length of the optical fiber jumper to be tested according to the adjacent frequency difference value, the adjacent frequency difference value and the length of the standard optical fiber jumper, wherein the power phase of the optical signal reflected by the standard optical fiber jumper is the same, the power phase of the optical signal reflected by the optical fiber jumper to be tested is the same, and the length of the standard optical fiber jumper.
And comparing the frequency difference value, which is adjacent to the same power phase of the optical signal reflected by the standard length optical fiber jumper, with the frequency difference value, which is adjacent to the same power phase of the optical signal reflected by the tested optical fiber jumper, and multiplying the obtained ratio by the length of the standard optical fiber jumper to obtain the length of the tested optical fiber jumper.
Namely, the ratio of the adjacent frequency difference values when the power of the optical signals reflected by the optical fiber jumpers with standard lengths is the same to the adjacent frequency difference values when the power of the optical signals reflected by the optical fiber jumpers to be tested is the same is:
Δf 1 /Δf 2 ＝L 2 /L 1 (8)
the length of the tested optical fiber jumper is:
L 2 ＝L 1 *(Δf 1 /Δf 2 )(9)。
wherein Δf 1 Adjacent frequency differences when the optical signals reflected by the standard length optical fiber jumpers are in the same phase; Δf 2 Adjacent frequency differences when the optical signals reflected by the tested optical fiber jumpers are in the same phase; l (L) 1 Is the length of a standard fiber optic jumper.
S104, comparing the initial value of the length of the optical fiber jumper to be tested with the measured value of the length of the optical fiber jumper to be tested, and identifying the on-off condition of the optical fiber jumper to be tested.
Comparing the initial value of the length of the tested optical fiber jumper with the measured value of the length of the tested optical fiber jumper, if the initial value and the measured value are equal, the tested optical fiber jumper is light-transmitting, and if the initial value and the measured value are not equal, the tested optical fiber jumper is light-cutting.
From the above description, it can be seen that one or more of the embodiments described above achieve the following technical effects:
(2) The method adopts a phase modulation method, and the length measurement precision of the middle-short optical fiber can be improved by modulating the accurate frequency resolution;
(2) The optical fiber jumper measuring device adopts a double-optical-path structure, the length of the standard length optical fiber can be changed, the measurement of the middle-short distance optical fiber jumper can be realized, and the measurement precision of the middle-short optical fiber jumper is improved;
(3) The modulation and demodulation circuit is adopted to modulate the visible light laser, so that the induction wavelength of the original 1310nm or 1550nm InGaAs photoelectric probe can be effectively avoided, and the length measurement of the optical fiber jumper can be realized;
(4) The invention adopts the modulation and demodulation circuit to modulate the frequency of the visible light laser, respectively measures the optical signals returned by the standard length optical fiber jumper and the measured optical fiber jumper, calculates the length of the middle-short distance optical fiber jumper by the adjacent frequency difference value when the two optical paths are in the same phase, has small modulation frequency range and can realize the accurate measurement of the middle-short distance optical fiber jumper.
While the foregoing description of the embodiments of the present invention has been presented in conjunction with the drawings, it should be understood that it is not intended to limit the scope of the invention, but rather, it is intended to cover all modifications or variations within the scope of the invention as defined by the claims of the present invention.
Claims (10)
1. The utility model provides a well short optical fiber jumper wire length measurement device which characterized in that, this device includes:
the visible light generating circuit is used for generating a visible light signal, dividing the visible light signal into two paths of light signals and respectively outputting the two paths of light signals to the standard optical fiber jumper length measuring circuit and the measured optical fiber jumper length measuring circuit;
the standard optical fiber jumper length measuring circuit is used for measuring an optical signal returned by the standard optical fiber jumper and converting the optical signal into an electric signal to be output to the modulation and demodulation circuit;
the measured optical fiber jumper length measuring circuit is used for measuring an optical signal returned by the measured optical fiber jumper and converting the optical signal into an electric signal to be output to the modulation and demodulation circuit;
the modulation and demodulation circuit is used for modulating the frequency of the visible light signal generated by the visible light generation circuit, demodulating the received two electric signals, respectively recording the same different frequency values of the optical signal phase returned by the standard optical fiber jumper and the same different frequency values of the optical signal phase returned by the tested optical fiber jumper, respectively calculating the same frequency difference value of the optical signal phase returned by the standard optical fiber jumper and the same frequency difference value of the optical signal phase returned by the tested optical fiber jumper, calculating the length of the tested optical fiber jumper according to the length of the standard optical fiber jumper, comparing the adjacent frequency difference value of the optical signal power phase reflected by the standard optical fiber jumper with the adjacent frequency difference value of the optical signal power phase reflected by the tested optical fiber jumper, and multiplying the obtained ratio with the length of the standard optical fiber jumper to obtain the length of the tested optical fiber jumper.
2. The device for measuring the length of the medium-short optical fiber jumper according to claim 1, wherein the visible light generating circuit comprises a visible light laser and a first coupler, and the visible light laser outputs a visible light signal to the first coupler; the first coupler divides the received visible light signal into two paths of light signals, one path of light signal is output to the standard optical fiber jumper length measuring circuit, and the other path of light signal is output to the measured optical fiber jumper length measuring circuit.
3. The device for measuring the length of the medium-short optical fiber jumper according to claim 1, wherein the standard optical fiber jumper length measuring circuit comprises a second coupler and a first photoelectric detector, the second coupler receives one path of optical signals output by the first coupler and outputs the optical signals to the standard optical fiber jumper, the optical signals are reflected back to the second coupler through the end face of the standard optical fiber jumper, the second coupler transmits the optical signals returned by the standard optical fiber jumper to the first photoelectric detector, and the first photoelectric detector converts the received optical signals into electric signals and outputs the electric signals to the modem circuit.
4. The device for measuring the length of the middle-short optical fiber jumper according to claim 1, wherein the measured optical fiber jumper length measuring circuit comprises a third coupler and a second photoelectric detector, the third coupler receives the other path of optical signals output by the first coupler and outputs the other path of optical signals to the measured optical fiber jumper, the optical signals are reflected back to the third coupler through the end face of the measured optical fiber jumper, the third coupler transmits the optical signals returned by the measured optical fiber jumper to the second photoelectric detector, and the second photoelectric detector converts the received optical signals into electric signals and outputs the electric signals to the modem circuit.
5. The device for measuring the length of the medium-short optical fiber jumper according to claim 1, wherein the modulation and demodulation circuit comprises a modulation circuit, a standard optical fiber optical signal demodulation circuit and a measured optical fiber optical signal demodulation circuit;
the modulating circuit comprises a central processing unit, a signal generator and a laser driver which are sequentially connected, wherein the central processing unit modulates the optical signals of the visible light laser through the signal generator and the laser driver;
the standard optical fiber optical signal demodulation circuit comprises a first photodiode, a first signal amplifier and a first phase comparator which are sequentially connected, wherein the first photodiode receives an optical signal returned by a standard length optical fiber jumper wire measured by the first photoelectric detector, the optical signal is amplified by the first signal amplifier and then is output to the first phase comparator, the first phase comparator compares the amplified optical signal with an original sine wave signal of the signal generator, and the comparison result is output to the central processor;
the optical signal demodulation circuit of the tested optical fiber comprises a second photodiode, a second signal amplifier and a second phase comparator which are sequentially connected, wherein the second photodiode receives an optical signal returned by a tested optical fiber jumper wire measured by the second photoelectric detector, the optical signal is amplified by the second signal amplifier and then is output to the second phase comparator, the second phase comparator compares the amplified optical signal with an original sine wave signal of the signal generator, and a comparison result is output to the central processor.
6. A method for measuring the length of a medium-short optical fiber jumper, which is realized based on the medium-short optical fiber jumper length measuring device according to any one of claims 1 to 5, and is characterized in that the method comprises the following steps:
the method comprises the steps of obtaining the modulation frequency of a visible light signal, and respectively calculating the power of an optical signal returned by a standard length optical fiber jumper and a tested optical fiber jumper;
respectively calculating the same adjacent frequency difference value of the optical signals returned by the standard length optical fiber jumper and the tested optical fiber jumper;
calculating the length of the tested optical fiber jumper by using the obtained adjacent frequency difference value;
and comparing the initial value of the length of the detected optical fiber jumper with the obtained length of the detected optical fiber jumper, and identifying the on-off condition of the detected optical fiber jumper.
7. The method for measuring the length of the medium-short optical fiber jumper according to claim 6, wherein the method for calculating the power of the optical signal returned by the standard length optical fiber jumper and the measured optical fiber jumper is as follows:
acquiring the initial frequency, the modulation speed and the working time of the visible light signal, and calculating the modulation frequency of the visible light signal at any moment;
calculating the power of the optical signal reflected back by the standard optical fiber jumper wire by utilizing the modulation frequency of the visible light signal;
and calculating the power of the optical signal reflected back by the tested optical fiber jumper wire by utilizing the modulation frequency of the visible light signal.
8. The method for measuring the length of a medium-short optical fiber jumper according to claim 6, wherein the method for calculating the same adjacent frequency difference value of the optical signal returned by the standard length optical fiber jumper and the measured optical fiber jumper is as follows:
recording different frequency values of the optical signals when the phase values of the optical signals returned by the standard optical fiber jumper are the same according to the optical signal power reflected by the standard optical fiber jumper, and differencing the recorded different frequency values of the optical signals to obtain the adjacent frequency difference value when the phase of the optical signals returned by the standard optical fiber jumper is the same;
and recording different frequency values of the optical signals when the power phase values of the optical signals returned by the tested optical fiber jumper are the same according to the power of the optical signals reflected by the tested optical fiber jumper, and differencing the recorded different frequency values of the optical signals to obtain the difference value between adjacent frequencies when the phases of the optical signals returned by the tested optical fiber jumper are the same.
9. The method for measuring the length of a medium-short optical fiber jumper according to claim 6, wherein the method for calculating the length of the optical fiber jumper to be measured comprises the following steps:
calculating the ratio of the adjacent frequency difference value of the same phase of the optical signal returned by the standard optical fiber jumper to the adjacent frequency difference value of the same phase of the optical signal returned by the tested optical fiber jumper, and multiplying the obtained ratio by the length of the standard optical fiber jumper to obtain the length of the tested optical fiber jumper.
10. The method for measuring the length of a medium-short fiber jumper according to claim 6, wherein the step of identifying the on-off condition of the measured fiber jumper comprises:
comparing the initial value of the length of the tested optical fiber jumper with the obtained measured value of the length of the tested optical fiber jumper;
if the initial value of the length of the tested optical fiber jumper is equal to the obtained measured value of the length of the tested optical fiber jumper, the tested optical fiber jumper is light-transmitting;
if the initial value of the length of the detected optical fiber jumper is unequal to the obtained measured value of the length of the detected optical fiber jumper, the detected optical fiber jumper is cut off.
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Citations (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2121429A1 (en) * | 1994-04-15 | 1995-10-16 | Joseph Emilien Germain Lamonde | Measurement of Attenuation of Optical Fibers Using Bidirectional Transmission of Information Via the Fiber |
| EP1381176A2 (en) * | 2002-07-09 | 2004-01-14 | KDDI Submarine Cable Systems Inc. | System for measuring chromatic dispersion |
| CN1494237A (en) * | 2002-10-28 | 2004-05-05 | 上海紫珊光电技术有限公司 | Ultra high speed optical fiber grating sensor demodulating system and its realizing method |
| CN102183234A (en) * | 2011-03-21 | 2011-09-14 | 清华大学 | Method and device for measuring frequency scanning absolute distance based on femtosecond optical frequency comb |
| WO2011134562A1 (en) * | 2010-04-30 | 2011-11-03 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e. V. | System for producing a signal having an adjustable time position or phase position |
| CN102788595A (en) * | 2012-07-27 | 2012-11-21 | 北京航空航天大学 | Optical fiber gyroscope frequency characteristic elevating method and device based on Faraday effect |
| CN103900623A (en) * | 2014-04-16 | 2014-07-02 | 武汉理工光科股份有限公司 | Optical time domain reflectometer based on double acoustic-optical modulators and common-mode rejection method of optical time domain reflectometer |
| JP2015012325A (en) * | 2013-06-26 | 2015-01-19 | 日本電信電話株式会社 | Crosstalk measuring device and crosstalk measuring method |
| CN106248118A (en) * | 2016-07-15 | 2016-12-21 | 武汉理工大学 | High wavelength resolution optical fiber grating regulating system and method |
| CN106452570A (en) * | 2016-09-22 | 2017-02-22 | 北京交通大学 | Optical fiber fault detection system and detection method based on optical fiber phase mediation principle |
| CN106969714A (en) * | 2017-05-02 | 2017-07-21 | 中国航空工业集团公司北京长城计量测试技术研究所 | A kind of method of the fine length of precise measuring |
| CN107976248A (en) * | 2016-10-25 | 2018-05-01 | 北京大学 | It can realize the distributed optical fiber sensing system and its measuring method of all phase demodulation |
| CN107991267A (en) * | 2017-11-29 | 2018-05-04 | 珠海任驰光电科技有限公司 | The tunable diode laser absorption spectroscopy gas-detecting device and method of wavelength agile |
| CN108088655A (en) * | 2017-12-18 | 2018-05-29 | 南京航空航天大学 | Optical device measuring method, device based on double sideband modulation and frequency displacement |
| CN108429580A (en) * | 2018-02-08 | 2018-08-21 | 武汉邮电科学研究院有限公司 | The measuring system and method for arbitrary point OSNR in a kind of optic communication links |
| CN108616311A (en) * | 2018-03-30 | 2018-10-02 | 西安电子科技大学 | A kind of device and method based on Mach-Zehnder type optical filter frequency measurements |
| JP6430044B1 (en) * | 2017-06-20 | 2018-11-28 | 三菱電機株式会社 | Laser radar apparatus and frequency modulation control method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9281893B2 (en) * | 2013-10-23 | 2016-03-08 | Lumentum Operations Llc | In-service monitoring of a fiberoptic network |
-
2018
- 2018-12-14 CN CN201811534185.9A patent/CN109391322B/en active Active
Patent Citations (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2121429A1 (en) * | 1994-04-15 | 1995-10-16 | Joseph Emilien Germain Lamonde | Measurement of Attenuation of Optical Fibers Using Bidirectional Transmission of Information Via the Fiber |
| EP1381176A2 (en) * | 2002-07-09 | 2004-01-14 | KDDI Submarine Cable Systems Inc. | System for measuring chromatic dispersion |
| CN1494237A (en) * | 2002-10-28 | 2004-05-05 | 上海紫珊光电技术有限公司 | Ultra high speed optical fiber grating sensor demodulating system and its realizing method |
| WO2011134562A1 (en) * | 2010-04-30 | 2011-11-03 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e. V. | System for producing a signal having an adjustable time position or phase position |
| CN102183234A (en) * | 2011-03-21 | 2011-09-14 | 清华大学 | Method and device for measuring frequency scanning absolute distance based on femtosecond optical frequency comb |
| CN102788595A (en) * | 2012-07-27 | 2012-11-21 | 北京航空航天大学 | Optical fiber gyroscope frequency characteristic elevating method and device based on Faraday effect |
| JP2015012325A (en) * | 2013-06-26 | 2015-01-19 | 日本電信電話株式会社 | Crosstalk measuring device and crosstalk measuring method |
| CN103900623A (en) * | 2014-04-16 | 2014-07-02 | 武汉理工光科股份有限公司 | Optical time domain reflectometer based on double acoustic-optical modulators and common-mode rejection method of optical time domain reflectometer |
| CN106248118A (en) * | 2016-07-15 | 2016-12-21 | 武汉理工大学 | High wavelength resolution optical fiber grating regulating system and method |
| CN106452570A (en) * | 2016-09-22 | 2017-02-22 | 北京交通大学 | Optical fiber fault detection system and detection method based on optical fiber phase mediation principle |
| CN107976248A (en) * | 2016-10-25 | 2018-05-01 | 北京大学 | It can realize the distributed optical fiber sensing system and its measuring method of all phase demodulation |
| CN106969714A (en) * | 2017-05-02 | 2017-07-21 | 中国航空工业集团公司北京长城计量测试技术研究所 | A kind of method of the fine length of precise measuring |
| JP6430044B1 (en) * | 2017-06-20 | 2018-11-28 | 三菱電機株式会社 | Laser radar apparatus and frequency modulation control method |
| CN107991267A (en) * | 2017-11-29 | 2018-05-04 | 珠海任驰光电科技有限公司 | The tunable diode laser absorption spectroscopy gas-detecting device and method of wavelength agile |
| CN108088655A (en) * | 2017-12-18 | 2018-05-29 | 南京航空航天大学 | Optical device measuring method, device based on double sideband modulation and frequency displacement |
| CN108429580A (en) * | 2018-02-08 | 2018-08-21 | 武汉邮电科学研究院有限公司 | The measuring system and method for arbitrary point OSNR in a kind of optic communication links |
| CN108616311A (en) * | 2018-03-30 | 2018-10-02 | 西安电子科技大学 | A kind of device and method based on Mach-Zehnder type optical filter frequency measurements |
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