CN114088356B - OFDR measuring device and method irrelevant to polarization - Google Patents
OFDR measuring device and method irrelevant to polarization Download PDFInfo
- Publication number
- CN114088356B CN114088356B CN202111385469.8A CN202111385469A CN114088356B CN 114088356 B CN114088356 B CN 114088356B CN 202111385469 A CN202111385469 A CN 202111385469A CN 114088356 B CN114088356 B CN 114088356B
- Authority
- CN
- China
- Prior art keywords
- light
- signal
- splitting
- polarization
- beat frequency
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M11/00—Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
- G01M11/02—Testing optical properties
- G01M11/0207—Details of measuring devices
Landscapes
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optical Communication System (AREA)
Abstract
The application relates to a polarization-independent OFDR measurement device and method, the device comprises: the device comprises an input module, a phase adjusting module, a polarization light splitting module, a coherent detection module and a signal processing module; the phase adjusting module is used for respectively carrying out phase delay adjustment on the split optical signals of the local oscillator light and the split optical signals of the target reflected light, carrying out pairwise coupling on the split optical signals of the local oscillator light and the split optical signals of the target reflected light after adjustment, splitting light and outputting a plurality of coupled split optical signals to the polarization splitting module; the polarization light splitting module is used for receiving each coupling light splitting signal and respectively carrying out polarization light splitting so as to correspondingly output the horizontal state polarized light and the vertical state polarized light of each coupling light splitting signal to the coherent detection module; and the coherent detection module is used for generating corresponding multi-channel beat signals according to the multiple groups of polarized light in the same state in a coherent mode so as to transmit the multi-channel beat signals to the signal processing module, and the signal processing module processes the multi-channel beat signals to obtain a spectrogram of the device to be detected. The method and the device can realize the performance of the polarization-free measurement optical fiber.
Description
Technical Field
The application relates to the technical field of optical fiber measurement, in particular to an OFDR measurement device and method irrelevant to polarization.
Background
At present, the measurement of the optical transmission performance of a distributed device to be measured based on an OFDR measurement technology is a common optical fiber loss measurement method. In related patent CN112461276A, a beat signal of an auxiliary interferometer is used to extract phase noise, and then the extracted phase noise is used to compensate a nonlinear phase of a main interferometer, in the scheme, an optical path is very sensitive to polarization and involves two coherent detection optical paths of the main interferometer and the auxiliary interferometer, and polarization on the optical path needs manual control, which is complicated and difficult to operate, has many devices, and is high in cost; and the measurement error may be large due to the bias adjustment error in practical use.
Disclosure of Invention
In view of the above, the present application provides a polarization-independent OFDR measurement apparatus and method, so as to solve the technical problem of how to implement non-polarization adjustment for OFDR measurement.
In order to solve the above problem, in a first aspect, the present application provides a polarization independent OFDR measuring apparatus, the apparatus comprising:
the device comprises an input module, a phase adjusting module, a polarization light splitting module, a coherent detection module and a signal processing module;
the input module is used for acquiring light to be measured and local oscillator light, transmitting the light to be measured to a device to be measured to acquire target reflected light, and respectively splitting the target reflected light and the local oscillator light and transmitting the split light to the phase adjustment module;
the phase adjusting module is used for respectively carrying out phase delay adjustment on the split optical signals of the local oscillator light and the split optical signals of the target reflected light, carrying out pairwise coupling on the split optical signals of the local oscillator light and the split optical signals of the target reflected light after adjustment, splitting light, and outputting a plurality of coupled split optical signals to the polarization splitting module;
the polarization light splitting module is used for receiving each coupling light splitting signal and respectively carrying out polarization light splitting so as to correspondingly output the horizontal polarization light and the vertical polarization light of each coupling light splitting signal to the coherent detection module;
the coherent detection module is used for generating corresponding multi-channel beat signals according to the multiple groups of polarized light in the same state in a coherent mode so as to transmit the multi-channel beat signals to the signal processing module;
and the signal processing module is used for receiving the multi-channel beat frequency signals, performing noise processing and signal combination processing to obtain a frequency spectrogram of the device to be tested.
Optionally, the apparatus further comprises: and the signal acquisition module is used for receiving the multi-channel beat frequency signals output by the coherent detection module at a high speed so as to transmit the multi-channel beat frequency signals to the signal processing module.
Optionally, the input module includes a laser, a first coupler, a second coupler, a circulator, and a first polarization splitting prism;
the laser is used for generating an original optical signal to be transmitted to the first coupler;
the first coupler is used for splitting the original optical signal to generate local oscillation light and to-be-detected light, transmitting the to-be-detected light to the circulator and transmitting the local oscillation light to the second coupler;
the circulator is used for outputting the received light to be detected to a device to be detected and outputting target reflected light to the first polarization splitting prism;
the first polarization splitting prism is used for carrying out polarization splitting on the target reflected light to obtain horizontal polarization splitting and vertical polarization splitting of the target reflected light, the horizontal polarization splitting of the target reflected light is used as a first reflection sub light, and the vertical polarization splitting of the target reflected light is used as a second reflection sub light;
and the second coupler is used for splitting the local oscillator light to output first local oscillator sub light and second local oscillator light of the local oscillator light.
Optionally, the phase adjustment module includes a first wave plate, a second wave plate, a third wave plate, a fourth wave plate, a third coupler, and a fourth coupler;
the first wave plate is used for receiving the first reflected sub-light, performing first phase difference delay adjustment and transmitting an adjusted corresponding optical signal to the third coupler;
the second wave plate is used for receiving the first local oscillator light, performing second phase difference delay adjustment and transmitting the adjusted corresponding light signal to the third coupler;
the third wave plate is used for receiving the second reflected sub-light, performing first phase difference delay adjustment and transmitting an adjusted corresponding optical signal to the fourth coupler;
the fourth wave plate is used for receiving the second local oscillator light, performing second phase difference delay adjustment and transmitting the adjusted corresponding light signal to the fourth coupler;
the third coupler is used for coupling the optical signals output after the first wave plate and the second wave plate are adjusted, and splitting light to output a first coupling split light signal and a second coupling split light signal;
and the fourth coupler is used for coupling the optical signals output after the adjustment of the third wave plate and the fourth wave plate and splitting light to output a third coupling splitting signal and a fourth coupling splitting signal.
Optionally, the polarization splitting module includes a second polarization splitting prism, a third polarization splitting prism, a fourth polarization splitting prism, and a fifth polarization splitting prism; the second polarization beam splitter prism is used for correspondingly receiving the first coupling beam splitting signal, the second coupling beam splitting signal, the third coupling beam splitting signal and the fourth coupling beam splitting signal, the second polarization beam splitter prism outputs a first horizontal polarization beam splitting and a first vertical polarization beam splitting of the first coupling beam splitting signal, the third polarization beam splitter prism outputs a second horizontal polarization beam splitting and a second vertical polarization beam splitting of the second coupling beam splitting signal, the fourth polarization beam splitter prism outputs a third horizontal polarization beam splitting and a third vertical polarization beam splitting of the third coupling beam splitting signal, and the fifth polarization beam splitter prism outputs a fourth horizontal polarization beam splitting and a fourth vertical polarization beam splitting of the fourth coupling beam splitting signal.
Optionally, the coherent detection module includes a first balanced detector, a second balanced detector, a third balanced detector and a fourth balanced detector;
the first balanced detector is used for receiving the first horizontal polarization beam splitter and the second horizontal polarization beam splitter and carrying out coherent detection to generate a first beat frequency signal;
the second balanced detector is used for receiving the first vertical polarization split light and the second vertical polarization split light and carrying out coherent detection to generate a second beat frequency signal;
the third balanced detector is used for receiving the third horizontal polarization split light and the fourth horizontal polarization split light and carrying out coherent detection to generate a third beat frequency signal;
and the fourth balanced detector is used for receiving the third vertical polarization split light and the fourth vertical polarization split light and carrying out coherent detection to generate a fourth beat frequency signal.
Optionally, the signal acquisition module adopts a four-way high-speed ADC device.
Optionally, the first wave plate and the third wave plate adopt a half wave plate, and the first phase difference is delayed by 180 degrees; the second wave plate and the fourth wave plate adopt a quarter wave plate, and the second phase difference is delayed by 90 degrees.
In a second aspect, the present application provides a measurement method for a polarization independent OFDR measurement apparatus, comprising:
acquiring a first beat frequency signal, a second beat frequency signal, a third beat frequency signal and a fourth beat frequency signal, and respectively performing analog-to-digital conversion;
and performing data noise pretreatment on the first beat frequency signal, the second beat frequency signal, the third beat frequency signal and the fourth beat frequency signal after analog-to-digital conversion, combining the pretreated first beat frequency signal, the pretreated second beat frequency signal, the pretreated third beat frequency signal and the pretreated fourth beat frequency signal, and drawing to obtain a spectrogram of the device to be tested.
Optionally, the data noise preprocessing is performed on the first beat signal, the second beat signal, the third beat signal, and the fourth beat signal after the analog-to-digital conversion, and the data noise preprocessing includes:
performing phase noise extraction on the analog-to-digital converted first beat frequency signal, second beat frequency signal, third beat frequency signal and fourth beat frequency signal to obtain a phase noise signal;
based on the phase noise signal, performing noise filtering processing on the first beat frequency signal, the second beat frequency signal, the third beat frequency signal and the fourth beat frequency signal;
and performing Fourier transform, inverse Fourier transform and deskew filtering on the first beat frequency signal, the second beat frequency signal, the third beat frequency signal and the fourth beat frequency signal after the noise filtering processing, then performing signal combination on the first beat frequency signal, the second beat frequency signal, the third beat frequency signal and the fourth beat frequency signal after the deskew filtering processing, and drawing a frequency spectrogram of the device to be tested according to the combined signals.
The beneficial effects of adopting the above embodiment are: in the embodiment, the polarization state of the target reflected light returned by the device to be tested is uncertain, but the target reflected light with the uncertain polarization state can be converted into the determined horizontal state and vertical state polarized light through the input module, the phase adjusting module and the polarization splitting module, so that a complicated mechanical device for manually adjusting the polarization state is omitted; then, a plurality of paths of beat frequency signals are generated through the coherent detection module, so that coherent failure caused by polarization fading in one direction can be avoided, a more accurate spectrogram is obtained, and the distribution condition of loss points in the device to be measured can be determined.
Drawings
FIG. 1 is a schematic block diagram of an embodiment of a polarization independent OFDR measurement apparatus provided herein;
FIG. 2 is a schematic block diagram of another embodiment of a polarization independent OFDR measurement apparatus provided herein;
FIG. 3 is a graph of a spectrum obtained from a first fiber optic measurement experiment provided herein;
fig. 4 is a frequency spectrum diagram obtained by a second optical fiber measurement experiment provided in the present application;
fig. 5 is a frequency spectrum diagram obtained by a third fiber measurement experiment provided in the present application.
Detailed Description
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate preferred embodiments of the application and together with the description, serve to explain the principles of the application and not to limit the scope of the application.
In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.
Referring to fig. 1, the present embodiment discloses a polarization-independent OFDR measurement apparatus, which includes: the device comprises an input module 101, a phase adjusting module 201, a polarization splitting module 301, a coherent detection module 401 and a signal processing module 501. The input module 101 is configured to acquire light to be measured and local oscillator light, transmit the light to be measured to a device to be measured to acquire target reflected light, split the target reflected light and the local oscillator light respectively, and transmit the split light to the phase adjustment module. The phase adjusting module 201 is configured to perform phase delay adjustment on the optical splitting signal of the local oscillator light and the optical splitting signal of the target reflection light, perform pairwise coupling on the optical splitting signal of the local oscillator light and the optical splitting signal of the target reflection light after adjustment, and output a first coupling optical splitting signal, a second coupling optical splitting signal, a third coupling optical splitting signal, and a fourth coupling optical splitting signal to the polarization optical splitting module. The polarization splitting module 301 is configured to perform polarization splitting on the received first, second, third, and fourth coupled split signals, so as to output horizontal polarized light and vertical polarized light of the first, second, third, and fourth coupled split signals to the coherent detection module correspondingly. The coherent detection module 401 is configured to coherently receive the polarized light in the same state of the first/second coupled optical splitting signal and generate a corresponding beat signal, so as to transmit the beat signal to the signal processing module; the signal processing module 501 is configured to receive the multiple beat frequency signals, perform noise processing and signal combination processing, and obtain a spectrogram of the device under test. The signal processing module 501 is further configured to receive the same-state polarized light of the third/fourth coupled optical splitting signals and coherently generate a corresponding beat signal, so as to transmit the beat signal to the signal processing module.
In this embodiment, the device under test refers to an optical passive device, such as an optical fiber, an optical fiber coupler, a wavelength division multiplexer, an optical modulator, an optical filter, an optical isolator, an optical circulator, and other optical communication products. The polarization state of the target reflected light returned by the device to be tested is uncertain, but the target reflected light with the uncertain polarization state can be converted into the determined horizontal state polarized light and the determined vertical state polarized light through the input module, the phase adjusting module and the polarization splitting module, so that a complicated mechanical device for manually adjusting the polarization state is omitted; then, four paths of beat frequency signals are generated through the coherent detection module, so that coherent failure caused by polarization fading in one direction can be avoided, a more accurate spectrogram is obtained, and the distribution condition of loss points in the device to be measured can be favorably determined.
In an embodiment, the polarization-independent OFDR measurement apparatus of this embodiment further includes a signal acquisition module 500, configured to receive the multiple beat signals output by the coherent detection module at a high speed, so as to transmit the multiple beat signals to the signal processing module. As shown in fig. 2, in the present embodiment, the signal acquisition module 500 employs a four-way high-speed ADC device 21, and the signal processing module 501 employs an FPGA device 22.
In this embodiment, referring to fig. 2, the input module 101 includes a laser 1, a first coupler 3, a circulator 4, a first polarization splitting prism 5, and a second coupler 6; a laser 1 for generating an original optical signal for transmission to a first coupler; the first coupler 3 is used for splitting an original optical signal to generate local oscillation light and light to be detected, transmitting the light to be detected to the circulator and transmitting the local oscillation light to the second coupler; a circulator 4 for outputting the received light to be measured to the device 2 to be measured and outputting a target reflected light
To a first polarization splitting prism; a first polarization beam splitter prism 5 for performing polarization beam splitting on the target reflected light to obtain horizontal polarization beam splitting of the target reflected light
And vertical polarization splitting
And horizontal polarization splitting of the target reflected light
As the first reflected sub-light, the vertical polarization of the target reflected light is split
As second reflected sub-light; a second coupler 6 for splitting the local oscillation light
To output local oscillator light
And a second resonator light
It should be noted that, the first coupler splits the original optical signal by 50% of the splitting ratio, respectively, to generate the local oscillation light and the light to be detected. In addition, the second coupler splits the local oscillator light according to the splitting ratio of 50%, the sizes of the generated first local oscillator sub-light and the second local oscillator sub-light are the same, and the same optical sign is adopted
And (4) showing. In the present embodiment, it is preferred that,
in the present embodiment, referring to fig. 2, the phase adjustment module 201 includes a first wave plate 7, a second wave plate 8, a third wave plate 9, a fourth wave plate 10, a third coupler 11, and a fourth coupler 12; in the embodiment, the first wave plate and the third wave plate adopt a half wave plate, and the first phase difference is delayed by 180 degrees; the second wave plate and the fourth wave plate adopt a quarter wave plate, and the second phase difference is delayed by 90 degrees.
The first wave plate 7 is used for receiving the first reflected sub-light, performing first phase difference delay adjustment, and transmitting an adjusted corresponding optical signal to the third coupler; the second wave plate 8 is used for receiving the first local oscillator light, performing second phase difference delay adjustment and transmitting the adjusted corresponding optical signal to the third coupler; the third wave plate 9 is used for receiving the second reflected sub-light, performing the first phase difference delay adjustment, and transmitting the adjusted corresponding optical signal to the fourth coupler; the fourth wave plate 10 is used for receiving the second local oscillator light, performing second phase difference delay adjustment, and transmitting the adjusted corresponding light signal to the fourth coupler; the third coupler 11 is configured to couple the optical signals output after the first wave plate and the second wave plate are adjusted, and split light to output a first coupled split light signal and a second coupled split light signal; and a fourth coupler 12, configured to couple the optical signals output after the third wave plate and the fourth wave plate are adjusted, and split the light to output a third coupled split signal and a fourth coupled split signal.
In a specific embodiment, the first local oscillator light
And a second resonator light
Respectively obtaining the four-wave plates after phase delay of 180 DEG
And
. First reflected sub-light
And a second reflected sub-light
Respectively obtaining the two-phase retardation by 90 DEG through a half wave plate
And
. The third coupler couples the first reflected sub-light after the phase delay and the first local oscillator light, and outputs a first coupled optical splitting signal:
and a second coupled optical split signal:
the fourth coupler couples the phase-delayed secondReflecting the sub-light and the second local oscillator light, and outputting a third coupling splitting signal:
and a fourth coupled optical split signal:
in this embodiment, referring to fig. 2, the polarization splitting module 301 includes a second polarization splitting prism 13, a third polarization splitting prism 14, a fourth polarization splitting prism 15, and a fifth polarization splitting prism 16; the second polarization beam splitter prism 13 outputs a first horizontal polarization beam splitter and a first vertical polarization beam splitter of the first coupling beam splitter signal, the third polarization beam splitter prism 14 outputs a second horizontal polarization beam splitter and a second vertical polarization beam splitter of the second coupling beam splitter signal, the fourth polarization beam splitter prism 15 outputs a third horizontal polarization beam splitter and a third vertical polarization beam splitter of the third coupling beam splitter signal, and the fifth polarization beam splitter prism 16 outputs a fourth horizontal polarization beam splitter and a fourth vertical polarization beam splitter of the fourth coupling beam splitter signal.
In a specific embodiment, the first coupled split signal and the second coupled split signal respectively pass through the second polarization splitting prism and the third polarization splitting prism, and are divided into two horizontal polarized lights and two vertical polarized lights with determined polarization relation, that is, the first horizontal polarization splitting light
And second horizontal polarization beam splitter
And first vertically polarized beam splitting
And second vertically polarized split light
The third coupling light splitting signal and the fourth coupling light splitting signal are divided into two paths of horizontal state polarized light and two paths of vertical state polarized light with determined polarization relation after respectively passing through a fourth polarization light splitting prism and a fifth polarization light splitting prism, namely, the third horizontal polarization light splitting
And fourth horizontal polarization split light
And third vertically polarized split light
And fourth vertically polarized split light
In the present embodiment, referring to fig. 2, the coherent detection module 401 includes a first balanced detector 17, a second balanced detector 18, a third balanced detector 19, and a fourth balanced detector 20; a first balance detector 17 for receiving the first horizontally polarized beam and the second horizontally polarized beam and coherently detecting to generate a first beat signal; a second balanced detector 18 for receiving the first vertically polarized beam split and the second vertically polarized beam split and performing coherent detection to generate a second beat signal; a third balanced detector 19 for receiving the third and fourth horizontal polarization split lights and performing coherent detection to generate a third beat signal; and a fourth balanced detector 20 for receiving the third vertically polarized beam and the fourth vertically polarized beam and performing coherent detection to generate a fourth beat signal.
In a specific embodiment, the first balanced detector receives the first and second horizontally polarized components and coherently detects to produce:
The embodiment discloses a measurement method of an OFDR measurement device independent of polarization, which comprises the following steps:
acquiring a first beat frequency signal, a second beat frequency signal, a third beat frequency signal and a fourth beat frequency signal, and respectively performing analog-to-digital conversion;
and performing data noise pretreatment on the first beat frequency signal, the second beat frequency signal, the third beat frequency signal and the fourth beat frequency signal after analog-to-digital conversion, combining the pretreated first beat frequency signal, the pretreated second beat frequency signal, the pretreated third beat frequency signal and the pretreated fourth beat frequency signal, and drawing to obtain a spectrogram of the device to be tested.
In an embodiment, the data noise preprocessing the first beat signal, the second beat signal, the third beat signal and the fourth beat signal after analog-to-digital conversion includes:
performing phase noise extraction on the analog-to-digital converted first beat frequency signal, second beat frequency signal, third beat frequency signal and fourth beat frequency signal to obtain a phase noise signal;
based on the phase noise signal, performing noise filtering processing on the first beat frequency signal, the second beat frequency signal, the third beat frequency signal and the fourth beat frequency signal;
and performing Fourier transform, inverse Fourier transform and deskew filtering on the first beat frequency signal, the second beat frequency signal, the third beat frequency signal and the fourth beat frequency signal after the noise filtering processing, then performing signal combination on the first beat frequency signal, the second beat frequency signal, the third beat frequency signal and the fourth beat frequency signal after the deskew filtering processing, and drawing a frequency spectrogram of the device to be tested according to the combined signals.
It should be noted that interpolation compensation processing may also be performed on the first beat signal, the second beat signal, the third beat signal, and the fourth beat signal after the noise filtering processing. In this embodiment, phase noise extraction is performed on any one of the four beat frequency signals through hilbert transform, and then noise irrelevant to the distance of the loss point of the device to be measured in the first beat frequency signal, the second beat frequency signal, the third beat frequency signal and the fourth beat frequency signal is filtered out through the phase noise signal by using the phase noise signal, so that the finally obtained frequency spectrogram is clean and clear.
In a specific embodiment, a single-mode fiber is selected as a device to be measured, the initial measurement frequency of the fiber to be measured is 170KHz, and the equivalent length is 1.36 meters. After the optical fiber to be measured is cut by 14mm in the first experiment, as shown in fig. 3, the measured interference beat frequency is 168.2KHz, the equivalent length is 1.3456 meters, the change frequency is 1.8KHz, and the equivalent change length is 14.4 mm. In the second experiment, after the optical fiber to be measured is cut off by 22.31mm, as shown in fig. 4, the measured interference beat frequency is 165.4KHz, the equivalent length is 1.3232 meters, the change frequency is 2.8KHz, and the equivalent change length is 22.4 mm. After the fiber to be measured is cut by 26.33mm in the third experiment, as shown in fig. 5, the measured interference beat frequency is 162.1KHz, the equivalent length is 1.3456 meters, the variation frequency is 3.3KHz, and the equivalent transformation length is 26.4 mm. Through three experiments, the spatial resolution of 0.4mm can be obtained under the conditions of low sampling rate and low frequency beat frequency, and the detection precision is high, so that the accurate positioning of the position of the loss point of the optical fiber to be detected is facilitated.
In the embodiment, the polarization state of the target reflected light returned by the device to be tested is uncertain, but the target reflected light with the uncertain polarization state can be converted into the determined horizontal state polarized light and the determined vertical state polarized light through the input module, the phase adjusting module and the polarization splitting module, so that a complicated mechanical device for manually adjusting the polarization state is omitted; then, a plurality of paths of beat frequency signals are generated through the coherent detection module, so that coherent failure caused by polarization fading in one direction can be avoided, a more accurate spectrogram is obtained, and the position of a loss point in a device to be measured is favorably determined.
It should be understood that, the sequence numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.
The above description is only for the preferred embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application.
Claims (10)
1. A polarization independent OFDR measurement apparatus, comprising: the device comprises an input module, a phase adjusting module, a polarization light splitting module, a coherent detection module and a signal processing module;
the input module is used for acquiring light to be measured and local oscillator light, transmitting the light to be measured to a device to be measured to acquire target reflected light, and respectively splitting the target reflected light and the local oscillator light and transmitting the split light to the phase adjustment module;
the phase adjusting module is used for respectively carrying out phase delay adjustment on the split optical signals of the local oscillator light and the split optical signals of the target reflected light, carrying out pairwise coupling on the split optical signals of the local oscillator light and the split optical signals of the target reflected light after adjustment, splitting light, and outputting a plurality of coupled split optical signals to the polarization splitting module;
the polarization light splitting module is used for receiving each coupling light splitting signal and respectively carrying out polarization light splitting so as to correspondingly output the horizontal state polarized light and the vertical state polarized light of each coupling light splitting signal to the coherent detection module;
the coherent detection module is used for generating corresponding multi-channel beat signals according to the multiple groups of polarized light in the same state in a coherent mode so as to transmit the multi-channel beat signals to the signal processing module;
and the signal processing module is used for receiving the multi-channel beat frequency signals, performing noise processing and signal combination processing to obtain a frequency spectrogram of the device to be tested.
2. The apparatus for polarization independent OFDR measurement according to claim 1, further comprising: and the signal acquisition module is used for receiving the multi-channel beat frequency signals output by the coherent detection module at a high speed so as to transmit the multi-channel beat frequency signals to the signal processing module.
3. The apparatus of claim 1, wherein the input module comprises a laser, a first coupler, a second coupler, a circulator and a first polarization splitting prism;
the laser is used for generating an original optical signal to be transmitted to the first coupler;
the first coupler is used for splitting the original optical signal to generate local oscillation light and to-be-detected light, transmitting the to-be-detected light to the circulator and transmitting the local oscillation light to the second coupler;
the circulator is used for outputting the received light to be detected to a device to be detected and outputting target reflected light to the first polarization splitting prism;
the first polarization splitting prism is used for carrying out polarization splitting on the target reflected light to obtain horizontal polarization splitting and vertical polarization splitting of the target reflected light, the horizontal polarization splitting of the target reflected light is used as a first reflection sub light, and the vertical polarization splitting of the target reflected light is used as a second reflection sub light;
and the second coupler is used for splitting the local oscillator light to output first local oscillator sub light and second local oscillator light of the local oscillator light.
4. The apparatus of claim 1, wherein the phase adjustment module comprises a first wave plate, a second wave plate, a third wave plate, a fourth wave plate, a third coupler, and a fourth coupler;
the first wave plate is used for receiving the first reflected sub-light, performing first phase difference delay adjustment and transmitting an adjusted corresponding optical signal to the third coupler;
the second wave plate is used for receiving the first local oscillator light, performing second phase difference delay adjustment and transmitting the adjusted corresponding light signal to the third coupler;
the third wave plate is used for receiving the second reflected sub-light, performing first phase difference delay adjustment and transmitting an adjusted corresponding optical signal to the fourth coupler;
the fourth wave plate is used for receiving the second local oscillator light, performing second phase difference delay adjustment and transmitting the adjusted corresponding light signal to the fourth coupler;
the third coupler is used for coupling the optical signals output after the first wave plate and the second wave plate are adjusted, and splitting light to output a first coupling split light signal and a second coupling split light signal;
and the fourth coupler is used for coupling the optical signals output after the adjustment of the third wave plate and the fourth wave plate and splitting light to output a third coupling splitting signal and a fourth coupling splitting signal.
5. The OFDR measurement apparatus of claim 1, wherein the polarization splitting module comprises a second polarization splitting prism, a third polarization splitting prism, a fourth polarization splitting prism and a fifth polarization splitting prism; the second polarization beam splitter prism is used for correspondingly receiving the first coupling beam splitting signal, the second coupling beam splitting signal, the third coupling beam splitting signal and the fourth coupling beam splitting signal, the second polarization beam splitter prism outputs a first horizontal polarization beam splitting and a first vertical polarization beam splitting of the first coupling beam splitting signal, the third polarization beam splitter prism outputs a second horizontal polarization beam splitting and a second vertical polarization beam splitting of the second coupling beam splitting signal, the fourth polarization beam splitter prism outputs a third horizontal polarization beam splitting and a third vertical polarization beam splitting of the third coupling beam splitting signal, and the fifth polarization beam splitter prism outputs a fourth horizontal polarization beam splitting and a fourth vertical polarization beam splitting of the fourth coupling beam splitting signal.
6. The OFDR measurement apparatus of claim 1, wherein the coherent detection module comprises a first balanced detector, a second balanced detector, a third balanced detector and a fourth balanced detector;
the first balanced detector is used for receiving the first horizontal polarization beam splitter and the second horizontal polarization beam splitter and carrying out coherent detection to generate a first beat frequency signal;
the second balanced detector is used for receiving the first vertical polarization split light and the second vertical polarization split light and carrying out coherent detection to generate a second beat frequency signal;
the third balanced detector is used for receiving the third horizontal polarization split light and the fourth horizontal polarization split light and carrying out coherent detection to generate a third beat frequency signal;
and the fourth balanced detector is used for receiving the third vertical polarization split light and the fourth vertical polarization split light and carrying out coherent detection to generate a fourth beat frequency signal.
7. The OFDR measurement apparatus of claim 2, wherein the signal acquisition module employs a four-way high-speed ADC device.
8. The apparatus of claim 4, wherein the first and third waveplates are half waveplates, the first phase difference is delayed by 180 °; the second wave plate and the fourth wave plate adopt a quarter wave plate, and the second phase difference is delayed by 90 degrees.
9. A measurement method of a polarization-independent OFDR measurement apparatus according to any one of claims 1 to 8, comprising:
acquiring a first beat frequency signal, a second beat frequency signal, a third beat frequency signal and a fourth beat frequency signal, and respectively performing analog-to-digital conversion;
and performing data noise pretreatment on the first beat frequency signal, the second beat frequency signal, the third beat frequency signal and the fourth beat frequency signal after analog-to-digital conversion, combining the pretreated first beat frequency signal, the pretreated second beat frequency signal, the pretreated third beat frequency signal and the pretreated fourth beat frequency signal, and drawing to obtain a spectrogram of the device to be tested.
10. The measurement method of the polarization-independent OFDR measurement apparatus according to claim 9, wherein the performing data noise preprocessing on the analog-to-digital converted first, second, third and fourth beat signals comprises:
performing phase noise extraction on the analog-to-digital converted first beat frequency signal, second beat frequency signal, third beat frequency signal and fourth beat frequency signal to obtain a phase noise signal;
based on the phase noise signal, performing noise filtering processing on the first beat frequency signal, the second beat frequency signal, the third beat frequency signal and the fourth beat frequency signal;
and performing Fourier transform, inverse Fourier transform and deskew filtering on the first beat frequency signal, the second beat frequency signal, the third beat frequency signal and the fourth beat frequency signal after the noise filtering processing, then performing signal combination on the first beat frequency signal, the second beat frequency signal, the third beat frequency signal and the fourth beat frequency signal after the deskew filtering processing, and drawing a frequency spectrogram of the device to be tested according to the combined signals.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111385469.8A CN114088356B (en) | 2021-11-22 | 2021-11-22 | OFDR measuring device and method irrelevant to polarization |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111385469.8A CN114088356B (en) | 2021-11-22 | 2021-11-22 | OFDR measuring device and method irrelevant to polarization |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114088356A CN114088356A (en) | 2022-02-25 |
| CN114088356B true CN114088356B (en) | 2022-06-17 |
Family
ID=80302676
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111385469.8A Active CN114088356B (en) | 2021-11-22 | 2021-11-22 | OFDR measuring device and method irrelevant to polarization |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114088356B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013007571A (en) * | 2011-06-22 | 2013-01-10 | Nippon Telegr & Teleph Corp <Ntt> | Laser beam coherence function measuring method and measuring apparatus |
| JP2015190910A (en) * | 2014-03-28 | 2015-11-02 | アンリツ株式会社 | Optical frequency domain reflection measuring method, optical frequency domain reflection measuring device, and apparatus for measuring position or shape using the same |
| CN107515017A (en) * | 2017-07-20 | 2017-12-26 | 北京航天控制仪器研究所 | A kind of optical frequency domain reflectometer of light wave frequency shift modulation |
| CN111735527A (en) * | 2020-06-01 | 2020-10-02 | 哈尔滨工业大学 | Optical fiber distributed vibration sensing method based on time domain phase calculation |
| CN112461276A (en) * | 2020-11-10 | 2021-03-09 | 电子科技大学 | System and method for reducing OFDR light source nonlinear phase influence |
-
2021
- 2021-11-22 CN CN202111385469.8A patent/CN114088356B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013007571A (en) * | 2011-06-22 | 2013-01-10 | Nippon Telegr & Teleph Corp <Ntt> | Laser beam coherence function measuring method and measuring apparatus |
| JP2015190910A (en) * | 2014-03-28 | 2015-11-02 | アンリツ株式会社 | Optical frequency domain reflection measuring method, optical frequency domain reflection measuring device, and apparatus for measuring position or shape using the same |
| CN107515017A (en) * | 2017-07-20 | 2017-12-26 | 北京航天控制仪器研究所 | A kind of optical frequency domain reflectometer of light wave frequency shift modulation |
| CN111735527A (en) * | 2020-06-01 | 2020-10-02 | 哈尔滨工业大学 | Optical fiber distributed vibration sensing method based on time domain phase calculation |
| CN112461276A (en) * | 2020-11-10 | 2021-03-09 | 电子科技大学 | System and method for reducing OFDR light source nonlinear phase influence |
Non-Patent Citations (2)
| Title |
|---|
| 基于光频域反射技术的光纤连续分布式定位应变传感;刘琨等;《中国激光》;20150510(第05期);第0505006-1-0505006-7页 * |
| 基于窄带光纤激光器的光频域反射计研究;叶蕾;《光纤与电缆及其应用技术》;20131025(第05期);第38-41页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114088356A (en) | 2022-02-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP2397813B1 (en) | Compensating for time varying phase changes in interferometric measurements | |
| CN108332785B (en) | Measuring device and method for large-scale fiber grating sensor | |
| US8854629B2 (en) | Optical coherence tomography system and method | |
| US7974541B2 (en) | High frequency signal optical transmission system and high frequency signal optical transmission method | |
| US20150043004A1 (en) | High speed high resolution heterodyne interferometric method and system | |
| CN107515017A (en) | A kind of optical frequency domain reflectometer of light wave frequency shift modulation | |
| CN109186644A (en) | Spectrum splices probe beam deflation type distributed fiberoptic sensor and signal demodulating method | |
| CN108873007B (en) | Frequency modulation continuous wave laser ranging device for inhibiting vibration effect | |
| CN100529715C (en) | Method for measuring birefraction optical devices phase-delay quantity and fast axis direction and device | |
| CN101858822A (en) | He-Ne laser frequency stability measuring system and measuring method thereof | |
| CN111947580B (en) | Multi-spliced sub-mirror multi-degree-of-freedom displacement monitoring system | |
| CN101915549B (en) | Orthogonal demodulation system for measuring phase and amplitude of medium-frequency signal in real time | |
| CN111928885A (en) | Femtosecond laser bidirectional time frequency clock difference measuring method and device | |
| CN114088356B (en) | OFDR measuring device and method irrelevant to polarization | |
| JP2018186473A (en) | Light fluctuation position measuring device, optical modulation converter, and light fluctuation position measuring method | |
| JP2006332999A (en) | System and method for reference signal light transmission | |
| JP7256777B2 (en) | Laser line width measurement device | |
| CN115711633A (en) | Phase noise accurate correction optical frequency domain reflectometer of loop structure reference interferometer | |
| CN115452015A (en) | Double-scale reference interference phase noise accurate correction optical frequency domain reflectometer | |
| Canavesi et al. | Polarization-and phase-sensitive low-coherence interferometry setup for the characterization of integrated optical components | |
| EP1523657B1 (en) | Delaying interferometer | |
| JP5380324B2 (en) | Polarization mode dispersion measuring apparatus and polarization mode dispersion measuring method | |
| CN103292916A (en) | Photoelectric receiver time stability test method based on double-acousto-optical frequency shift | |
| CN103292917A (en) | Photoelectric receiver time stability test method based on acousto-optical amplitude modulation | |
| CN113720484B (en) | Attosecond precision timing detection device and method based on linear optical effect |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |