CN116046036B - Optical sensing demodulation system - Google Patents
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- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
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- G01D5/35306—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement
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- G01D5/35306—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement
- G01D5/35309—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement using multiple waves interferometer
- G01D5/35316—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement using multiple waves interferometer using a Bragg gratings
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Abstract
The application discloses optical sensing demodulation system relates to the technical field of sensors, and aims to solve the technical problems that detection content is single and accurate measurement is difficult to achieve in the prior art. The optical sensing demodulation system comprises a coupler, a first demodulation optical path and at least one second demodulation optical path. The first demodulation light path comprises an adjustable FP filter, and one end of the adjustable FP filter is connected with the coupler; the tunable FP filter is configured to output amplified optical power when a center wavelength of the received optical signal is equal to a tuning wavelength of the tunable FP filter; the center wavelength corresponds to the amplitude of the sensing signal; each second demodulation light path comprises a matching grating, and one end of the matching grating is connected with the coupler; the matching grating is configured to modulate the intensity of the optical signal when the center wavelength of the optical signal is shifted; the rate of change of the intensity of the optical signal corresponds to the frequency of the sensing signal. Therefore, the method has the advantages of reducing cost, comprehensively measuring and improving the performance of the optical sensing demodulation system.
Description
Technical Field
The application relates to the technical field of sensors, in particular to an optical sensing demodulation system.
Background
In the prior art, an FBG (Fiber Bragg Grating, fiber grating) wavelength demodulation system is a demodulation system that changes the central wavelength of an FBG by changing external factors, and further changes the output optical power, thereby reflecting the external physical quantity and the change quantity thereof. The working principle of the system is as follows: the optical signal is input into the FBG sensor by the light source, and the FBG sensor is subjected to the modulation action of external physical quantity parameters, and the central wavelength of the FBG sensor correspondingly shifts. After the optical signal passes through the demodulation device, the intensity of the optical signal with the changed central wavelength is modulated and then changed, and finally the optical signal is transmitted to the photoelectric detector through the optical fiber to obtain the measured physical quantity parameter.
In the technical field of FBG sensing, the wavelength demodulation technology affects the detection performance of the whole sensing system. After modulation via the measured physical quantity, the FBG signal is typically composed of both frequency and amplitude factors. In the prior art, the FBG demodulation method can only detect the frequency or amplitude information of the FBG sensing signal independently at high frequency, and cannot detect the frequency or amplitude information accurately. For example, the edge filtering demodulation method reflects the drift amount of the FBG wavelength by demodulating the change of the optical signal intensity, and the method can eliminate the interference of external environmental factors such as unstable light source and the like through a reference light path, but is only suitable for demodulating high-frequency dynamic signals and cannot detect low-frequency or static signals; in addition, the method can accurately detect the frequency information of the signal, but cannot accurately detect the amplitude information. The demodulation method of the adjustable filter can accurately detect the amplitude information of the signal, but cannot accurately measure the information with higher frequency. In addition, the method is not suitable for demodulation of high frequency signals due to the modulation rate of the driving voltage of the feedback system. Therefore, the existing FBG wavelength demodulation technology is difficult to be compatible with accurate detection of frequency and amplitude information, and has certain limitation in function.
Disclosure of Invention
The utility model aims at providing a light sensing demodulation system, it is through the frequency and the accurate demodulation of amplitude information of two kinds of different demodulation devices simultaneously of many light path demodulation structure with the sensing signal, has realized all-round detection and signal source locate function, effectively reduces demodulation system's cost, is favorable to promoting the large-scale application of FBG sensor.
Embodiments of the present application are implemented as follows:
an embodiment of the present application provides, in a first aspect, an optical sensing demodulation system, including: a coupler, a first demodulation optical path, and at least one second demodulation optical path. The first demodulation light path comprises an adjustable FP filter, and one end of the adjustable FP filter is connected with the coupler; the tunable FP filter is configured to output amplified optical power when a center wavelength of the received optical signal is equal to a tuning wavelength of the tunable FP filter, the center wavelength corresponding to an amplitude of the sensing signal; each second demodulation light path comprises a matching grating, and one end of the matching grating is connected with the coupler; the matching grating is configured to modulate the intensity of the optical signal when the center wavelength of the optical signal is shifted; the rate of change of the intensity of the optical signal corresponds to the frequency of the sensing signal.
In an embodiment, the optical sensing demodulation system further includes a sensing signal acquisition module; the sensing signal acquisition module comprises a first circulator and a sensing grating array, wherein the first end of the first circulator is connected with one end of the sensing grating array; the second end of the first circulator is connected to the coupler.
In one embodiment, the sensing grating array comprises at least one sensing grating, and the sensing gratings are in one-to-one correspondence with modulation wave bands of the matched gratings; the sensing grating is configured to reflect an optical signal corresponding to the sensing signal.
In an embodiment, when the sensing grating array includes a plurality of sensing gratings, the sensing gratings are connected in series, and the sensing grating at the end point is connected to the first end of the first circulator.
In an embodiment, the optical sensing demodulation system further includes a broadband light source, and the broadband light source is connected to the input end of the first circulator.
In an embodiment, the optical sensing demodulation system further includes an electrical control system; the electronic control system comprises a control feedback module which is connected with the adjustable FP filter; the control feedback module is configured to output a periodically varying driving voltage to change the tuning wavelength of the tunable FP filter.
In one embodiment, the tunable FP filter comprises a piezoelectric ceramic, which is electrically coupled to the control feedback module.
In one embodiment, the matched grating is a transmissive grating or a reflective grating.
In an embodiment, the optical sensing demodulation system further comprises an electric control system, wherein the electric control system comprises an AD acquisition module and a plurality of photoelectric detectors, one end of one photoelectric detector is connected with the other end of the adjustable FP filter or the other end of one matching grating, and the other ends of the photoelectric detectors are connected with the AD acquisition module.
In an embodiment, when the matched grating is a reflection-type grating, the second demodulation optical path corresponding to the reflection-type grating further includes a second circulator; the input end of the second circulator is connected with the coupler, and the two output ends of the second circulator are respectively connected with the reflection type grating and the photoelectric detector.
Compared with the prior art, the beneficial effects of this application are: the application provides an optical sensing demodulation system, which adopts two different demodulation devices on a demodulation light path part based on the FBG wavelength modulation principle, realizes the simultaneous demodulation work of amplitude and frequency information of a high-frequency sensing signal, and solves the demodulation problems of high speed and high precision while ensuring low cost; in addition, the method can also utilize multi-azimuth detection demodulation signals to position the signal source. The optical sensing demodulation system provided by the application is strong in practicality and excellent in performance, and is favorable for pushing the large-scale application of the FBG sensor.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting the scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic structural diagram of an optical sensing demodulation system according to an embodiment of the present application;
fig. 2 is a schematic diagram of a principle of sideband filtering demodulation according to an embodiment of the present application.
Icon: 1-an optical sensing demodulation system; 10-a sensing signal acquisition module; 101-a first circulator; 1010-input; 1011-a first end; 1012-second end; 100-a sensing grating array; 102-sensing a grating; 11-a first demodulation light path; a 111-tunable FP filter; 12-a second demodulation optical path; 121-matching a grating; 13-an electronic control system; 131-a control feedback module; 132-AD acquisition module; 133-photodetectors; a 14-coupler; 15-broadband light source.
Detailed Description
The terms "first," "second," "third," and the like are used merely for distinguishing between descriptions and not for indicating a sequence number, nor are they to be construed as indicating or implying relative importance.
Furthermore, the terms "horizontal," "vertical," "overhang," and the like do not denote a requirement that the component be absolutely horizontal or overhang, but rather may be slightly inclined. As "horizontal" merely means that its direction is more horizontal than "vertical", and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.
In the description of the present application, it should be noted that, directions or positional relationships indicated by terms such as "inner", "outer", "left", "right", "upper", "lower", etc. are directions or positional relationships based on those shown in the drawings, or those that are conventionally put in use for the product of the application, are merely for convenience of description and simplification of the description, and are not indicative or implying that the apparatus or element to be referred to must have a specific direction, be configured and operated in a specific direction, and therefore should not be construed as limiting the present application.
In the description of the present application, unless explicitly stated and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements.
The technical solutions of the present application will be clearly and completely described below with reference to the accompanying drawings.
In the field of optical sensors, a fiber bragg grating wavelength demodulation system is favored because of the unique advantages of simple principle, reliable performance, flexible design, capability of ignoring error fluctuation generated by optical power and the like, and has been widely applied to the measurement fields of vibration, pressure, displacement, strain, temperature, acceleration and the like.
Referring to fig. 1, fig. 1 is a schematic structural diagram of an optical sensing demodulation system 1 according to an embodiment of the disclosure. As shown in fig. 1, the present application provides an optical sensing demodulation system 1, including: the system comprises a broadband light source 15, a sensing signal acquisition module 10, a coupler 14, a first demodulation light path 11, at least one second demodulation light path 12 and an electric control system 13.
In an embodiment, the broadband light source 15 provided in the present application is an ASE broadband light source, and other light source devices such as SLEDs may be used as the broadband light source 15.
The sensing signal acquisition module 10 includes a first circulator 101 and a sensing grating array 100, where the first circulator 101 has an input end 1010 and two output ends, i.e. a first end 1011 and a second end 1012. The broadband light source 15 is connected to the input 1010 of the first circulator 101; a first end 1011 of the first circulator 101 is connected to one end of the sensor grating array 100; a second end 1012 of the first circulator 101 is connected to the coupler 14.
In one embodiment, the sensing grating array 100 includes at least one sensing grating 102; the sensing grating 102 is configured to reflect an optical signal corresponding to the sensing signal. When the sensing grating array 100 includes a plurality of sensing gratings 102, the plurality of sensing gratings 102 are connected in series, and the sensing grating 102 at the end point is connected to the first end 1011 of the first circulator 101.
In an embodiment, the sensing grating 102 is a common fiber bragg grating, or may be a fiber bragg grating or a phase shift fiber bragg grating obtained by tapering, or may be replaced by a certain packaging structure or other sensing devices with the same function, for example: FP sensor, micro-ring sensor, etc.
In one embodiment, the coupler 14 is a fiber optic coupler for dividing the optical signal into multiple paths according to a predetermined ratio. In one embodiment, the coupler 14 averages the optical signals based on the total number of the first demodulation optical path 11 and the second demodulation optical path 12, and the optical signal intensities in the demodulation optical paths are the same. In other embodiments of the present application, the splitting ratio of each demodulation optical path may also be different.
As shown in fig. 1, in an application process, an optical signal generated by the broadband light source 15 is input to each sensing grating 102 in the sensing grating array 100 through the first circulator 101, and one sensing grating 102 corresponds to an optical signal of a specific wavelength band. When a sensing signal such as a vibration signal, a temperature signal, a pressure signal, etc. corresponding to a certain sensing grating 102 is changed, the sensing grating 102 correspondingly modulates or processes an optical signal of a specific wavelength band corresponding to the sensing signal, and reflects the optical signal back to the first circulator 101. The first circulator 101 transmits the reflected optical signal with the information about the center wavelength of the sensor grating to the one-to-many coupler 14 via the second end 1012. The coupler 14 inputs the same optical signals divided into multiple paths to the first demodulation optical path 11 and the respective second demodulation optical paths 12, respectively, for information demodulation.
The first demodulation optical path 11 comprises an adjustable FP filter 111, and one end of the adjustable FP filter 111 is connected to the coupler 14; the tunable FP filter 111 is configured to: when the center wavelength of the received optical signal is equal to the tuning wavelength of the tunable FP filter 111, the amplified optical power is output. Wherein the center wavelength of the optical signal corresponds to the amplitude of the sensing signal.
Each second demodulation optical path 12 comprises a matching grating 121, the sensing gratings 102 are in one-to-one correspondence with modulation wave bands of the matching gratings 121, and one end of the matching grating 121 is connected with the coupler 14; the matching grating 121 is configured to modulate the intensity of the optical signal when the center wavelength of the optical signal is shifted; wherein the rate of change of the intensity of the optical signal corresponds to the frequency of the sensing signal.
The electronic control system 13 includes a control feedback module 131, an AD acquisition module 132, and a plurality of photodetectors 133. Wherein, the control feedback module 131 is connected with the tunable FP filter 111; the tunable FP filter 111 comprises a piezoelectric ceramic electrically coupled to the control feedback module 131. The photodetectors are used for converting optical power into electrical signals, and one end of one photodetector 133 is connected with the other end of the tunable FP filter 111 or the other end of one matching grating 121; the other end of each photodetector 133 is connected to the AD acquisition module 132.
For the first demodulation optical path 11, the control feedback module 131 is configured to output a driving voltage that varies periodically, so as to periodically change the tuning wavelength of the tunable FP filter 111 through the piezoelectric ceramic, and finally determine the amplitude information of the sensing signal through the tuning wavelength and the driving voltage, with the following specific principle:
the cavity length of the demodulation light path of the adjustable FP filter 111 can be changed by the pressure of the piezoelectric ceramic to realize linear scanning within a certain specific length range, and correspondingly, the transmission wavelength of the adjustable FP filter 111 is changed within a period range. When the center wavelength of the optical signal reflected by the sensing grating 102 coincides with the transmission wavelength of the tunable FP filter 111, the photodetector 133 connected to the tunable FP filter 111 detects the best superimposed optical power.
According to the theory of interference of FP cavity, when the wavelength of incident light is equal to the tuning wavelength of tunable FP filter 111 (i.e.
When the transmitted light intensity of the tunable FP filter 111 reaches a maximum value. The tuning wavelength calculation formula of the tunable FP filter 111 is as follows (1).
Wherein, the liquid crystal display device comprises a liquid crystal display device,
tuning wavelength in nm for tunable FP filter 111;nis the refractive index of the medium within tunable FP filter 111;dthe cavity length of the tunable FP filter 111 is in μm;mis a positive integer. The feedback module 131 is controlled to output a driving voltage which changes periodically, so that the cavity length or the refractive index of the medium can be changed periodically, and the tuning wavelength of the tunable FP filter 111 can be changed.
The cavity length of the tunable FP filter 111 is controlled by a piezoelectric ceramic (PZT), and triangular waves are loaded on the piezoelectric ceramic by controlling the feedback module 131, so that the cavity length of the tunable FP filter 111 linearly changes with the tuning voltage (or driving voltage) in each period, and the relationship between the cavity length and the tuning voltage is as shown in the following formula (2).
d=kV+d 0 （2）
Wherein, the liquid crystal display device comprises a liquid crystal display device,dthe FP cavity length of the tunable FP filter 111 after loading the tuning voltage in μm;ktuning coefficients (constant values);Vthe unit is V for tuning voltage;d 0 the original cavity length is given in μm.
Simultaneously the formula (1) and the formula (d)2) Can obtain a tuned wavelength
And tuning voltageVThe relationship between them is shown in the following formula (3).
When tuning voltageVTuning wavelength when changed
And changes as the tuning wavelength of tunable FP filter 111 coincides with the center wavelength of the optical signal reflected by sensing grating 102, the optical power at that time is maximized.
Since the effective value of the driving voltage of the tunable FP filter 111 is the actual sampling voltage
I.e. the voltage peak actually collected, is the effective value of the driving voltage of the tunable FP filter 111 (i.e. the tuning voltageV) Is->
Multiple times. When the optical power reaches the maximum, the amplitude information of the sensing signal can be deduced based on the relation between the tuning voltage and the tuning wavelength.
For the second demodulation optical path 12, the frequency information of the sensing signal will shift the spectrum of the optical signal reflected by the sensing grating 102, so that the frequency information can be deduced according to the change rate of the optical signal intensity, and the specific principle is as follows:
in one embodiment, all the matched gratings 121 in the second demodulation optical path 12 are transmissive gratings. For the plurality of second demodulation light paths 12, the matching grating 121 can be directly connected between the coupler 14 and the photodetector 133, and the center wavelength of the matching grating 121 with a narrow linewidth is locked at the center position of the reflection spectrum line hypotenuse of the sensing grating 102 through the linear region of the spectrum line of the optical signal reflected by the sensing grating 102. Referring to fig. 2, fig. 2 is a schematic diagram illustrating a principle of sideband filtering demodulation according to an embodiment of the present application. As shown in fig. 2, when an external environment parameter (i.e., a physical quantity to be measured corresponding to the sensing grating 102) changes and acts on the sensing grating 102, the reflection spectrum of the sensing grating 102 shifts. Correspondingly, since the matching grating 121 is narrow in line width, the reflection spectrum of the matching grating is narrow relative to the reflection spectrum of the sensing grating, and the central wavelength corresponding to the peak value of the matching grating 121 can be locked at the central position of the hypotenuse of the reflection spectrum line of the wider sensing grating 102. Thus, the spectral line hypotenuse of the reflection spectrum modulates the intensity of the optical signal, and the frequency information of the dynamic sensing signal can be obtained from the light intensity change rate measured by the matching grating 121.
The matching grating 121 is a transmission type grating or a reflection type grating. When the matching grating 121 is a reflection-type grating, the second demodulation optical path 12 corresponding to the reflection-type grating further includes a second circulator; the second circulator also comprises an input end and two output ends, wherein the input end of the second circulator is connected with the coupler 14, and the two output ends of the second circulator are respectively connected with the reflection type grating and the photoelectric detector 133.
For the sensing signal positioning function of the optical sensing demodulation system 1, when the sensing signal detected by a certain sensing grating 102 in the sensing grating array 100 changes, the sensing grating 102 modulates and reflects the optical signal, the optical signal with the changed central wavelength is demodulated by the tunable FP filter 111, and the band to which the central wavelength of the modulated optical signal belongs can be confirmed, so that the position of the sensing grating 102 with the changed sensing signal can be confirmed according to the optical signal modulation band corresponding to each sensing grating 102, thereby realizing the signal source positioning function of the optical sensing demodulation system 1. Alternatively, the modulation bands of the optical signals of the respective sensing gratings 102 are in one-to-one correspondence with the modulation bands of the matching gratings 121 in the respective second demodulation optical paths 12. Therefore, when the sensing signal detected by a certain sensing grating 102 changes, the corresponding matching grating 121 with the same modulation band can demodulate the light intensity change information of the light signal in the band, so as to determine the position of the sensing grating 102 where the sensing signal changes, and realize the signal source positioning function of the optical sensing demodulation system 1.
In the embodiment of the present application, the control feedback module 131 and the AD acquisition module 132 may be independent and modularized integrated; the photodetector 133, the control feedback module 131, and the AD acquisition module 132 may also be soldered on the same integrated circuit board.
In an embodiment, the sensing signal detected by the optical sensing demodulation system 1 provided in the present application is a vibration signal; in other embodiments of the present application, fiber optic sensing devices that test other parameter types (sensing signals) are equally suitable for use in the present system, such as pressure signals, displacement signals, temperature signals, and the like.
In an embodiment, the optical sensing demodulation system 1 provided in the present application may be further matched with general devices such as a data acquisition device, a power supply device, and a data processing host computer, and the specific structure thereof is not described herein.
The optical sensing demodulation system 1 provided by the application realizes the omnibearing and simultaneous detection of the sensing signals by means of measuring the frequency and amplitude information of the sensing signals respectively through various demodulation light paths. For the sensing gratings 102 corresponding to different center wavelengths, the signal source can be positioned by using the demodulation signals. In addition, the method can solve the high-speed acquisition requirement on a subsequent hardware system by using a lower acquisition rate based on the change rate of the light intensity of the optical signal, effectively reduce the manufacturing cost of the optical sensing demodulation system 1, improve the practicability and the usability of the optical sensing demodulation system 1, and facilitate the promotion of the large-scale application of the sensing fiber bragg grating and the optical sensing demodulation system 1.
For example, the bandwidth of the existing demodulation system is 100nm, and the resolution is 0.5nm. For a vibration signal with a wavelength of 1nm and a frequency of 1000Hz, if the wavelength is directly demodulated by an existing demodulation system, the acquisition rate of the hardware system is required to be above 1000×2×100× (1/0.5) =400 kHz; if the optical sensing demodulation system provided by the application is adopted, demodulation is performed through the change rate of the optical signal light intensity, and only the acquisition rate of 1000×2=2 kHz is needed. Therefore, the method and the device can solve the high-speed acquisition requirement on the subsequent hardware system through a lower acquisition rate aiming at the change rate of the light intensity of the optical signal.
The foregoing description is only of the preferred embodiments of the present application and is not intended to limit the same, but rather, various modifications and variations may be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.
Claims (10)
1. An optical sensing demodulation system, comprising:
a coupler;
the first demodulation optical path comprises an adjustable FP filter, and one end of the adjustable FP filter is connected with the coupler; the tunable FP filter is configured to output amplified optical power when a center wavelength of the received optical signal is equal to a tuning wavelength of the tunable FP filter, the center wavelength corresponding to an amplitude of the sensing signal;
at least one second demodulation light path, wherein each second demodulation light path comprises a matching grating, and one end of the matching grating is connected with the coupler; the matching grating is configured to modulate the intensity of the optical signal when the center wavelength of the optical signal is shifted; the rate of change of the intensity of the optical signal corresponds to the frequency of the sensing signal.
2. The optical sensing demodulation system of claim 1, further comprising a sensing signal acquisition module;
the sensing signal acquisition module comprises a first circulator and a sensing grating array, wherein the first end of the first circulator is connected with one end of the sensing grating array; the second end of the first circulator is connected to the coupler.
3. The optical sensing demodulation system according to claim 2, wherein the sensing grating array comprises at least one sensing grating, and the sensing gratings are in one-to-one correspondence with modulation bands of the matching gratings; the sensing grating is configured to reflect an optical signal corresponding to the sensing signal.
4. The optical sensing demodulation system of claim 3 wherein when the sensing grating array comprises a plurality of sensing gratings, the plurality of sensing gratings are connected in series and the sensing grating at the end point is connected to the first end of the first circulator.
5. The optical sensor demodulation system of claim 2 further comprising a broadband light source connected to the input of the first circulator.
6. The optical sensing demodulation system of claim 1 further comprising an electronic control system;
the electronic control system comprises a control feedback module, and the control feedback module is connected with the adjustable FP filter; the control feedback module is configured to output a periodically varying drive voltage to change the tuning wavelength of the tunable FP filter.
7. The optical sensing demodulation system of claim 6 wherein the tunable FP filter comprises a piezoelectric ceramic, the piezoelectric ceramic being electrically connected to the control feedback module.
8. The optical sensing demodulation system of claim 1 wherein the matched grating is a transmissive grating or a reflective grating.
9. The optical sensor demodulation system according to claim 1, further comprising:
the electronic control system comprises an AD acquisition module and a plurality of photoelectric detectors, one end of each photoelectric detector is connected with the other end of the adjustable FP filter or the other end of the matched grating, and the other ends of the photoelectric detectors are connected with the AD acquisition module.
10. The optical sensing demodulation system according to claim 9, wherein when the matched grating is a reflection type grating, the second demodulation optical path corresponding to the reflection type grating further comprises a second circulator; the input end of the second circulator is connected with the coupler, and the two output ends of the second circulator are respectively connected with the reflection type grating and the photoelectric detector.
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1851414A (en) * | 2006-05-31 | 2006-10-25 | 中国科学院上海光学精密机械研究所 | Optical Bragg grating sensing system of eliminating sensitiveness |
| CN2916581Y (en) * | 2006-05-31 | 2007-06-27 | 中国科学院上海光学精密机械研究所 | Optical fiber Prague raster sensing device for eliminating mutual interference |
| CN101055167A (en) * | 2007-05-29 | 2007-10-17 | 北京交通大学 | Beam-scanning interference type nano surface tri-dimensional on-line measuring system and method |
| CN101241029A (en) * | 2007-02-09 | 2008-08-13 | 中国计量学院 | Optical fiber Bragg grating sensor demodulator |
| CN101718942A (en) * | 2009-11-25 | 2010-06-02 | 北京航空航天大学 | Multi-channel fiber Bragg grating (FBG) demodulator |
| CN105806379A (en) * | 2014-12-30 | 2016-07-27 | 深圳先进技术研究院 | Weak reflection fiber Bragg grating-Fabry-Perot cavity sensor demodulation system |
| CN106338308A (en) * | 2016-08-25 | 2017-01-18 | 武汉理工大学 | Distributed multi-parameter sensing system based on ultra-short fiber Bragg grating array |
| CN111313217A (en) * | 2020-03-31 | 2020-06-19 | 中国人民解放军军事科学院国防科技创新研究院 | All-fiber architecture mode-hopping induced noise suppression device and suppression method |
| CN111337060A (en) * | 2020-03-17 | 2020-06-26 | 南京信息工程大学 | Hybrid sensor based on vernier effect of parallel structure and manufacturing method thereof |
| CN113155165A (en) * | 2021-05-14 | 2021-07-23 | 武汉理工大学 | Interference type demodulation system and method for large-capacity fiber grating sensor network |
-
2023
- 2023-04-03 CN CN202310342478.1A patent/CN116046036B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1851414A (en) * | 2006-05-31 | 2006-10-25 | 中国科学院上海光学精密机械研究所 | Optical Bragg grating sensing system of eliminating sensitiveness |
| CN2916581Y (en) * | 2006-05-31 | 2007-06-27 | 中国科学院上海光学精密机械研究所 | Optical fiber Prague raster sensing device for eliminating mutual interference |
| CN101241029A (en) * | 2007-02-09 | 2008-08-13 | 中国计量学院 | Optical fiber Bragg grating sensor demodulator |
| CN101055167A (en) * | 2007-05-29 | 2007-10-17 | 北京交通大学 | Beam-scanning interference type nano surface tri-dimensional on-line measuring system and method |
| CN101718942A (en) * | 2009-11-25 | 2010-06-02 | 北京航空航天大学 | Multi-channel fiber Bragg grating (FBG) demodulator |
| CN105806379A (en) * | 2014-12-30 | 2016-07-27 | 深圳先进技术研究院 | Weak reflection fiber Bragg grating-Fabry-Perot cavity sensor demodulation system |
| CN106338308A (en) * | 2016-08-25 | 2017-01-18 | 武汉理工大学 | Distributed multi-parameter sensing system based on ultra-short fiber Bragg grating array |
| CN111337060A (en) * | 2020-03-17 | 2020-06-26 | 南京信息工程大学 | Hybrid sensor based on vernier effect of parallel structure and manufacturing method thereof |
| CN111313217A (en) * | 2020-03-31 | 2020-06-19 | 中国人民解放军军事科学院国防科技创新研究院 | All-fiber architecture mode-hopping induced noise suppression device and suppression method |
| CN113155165A (en) * | 2021-05-14 | 2021-07-23 | 武汉理工大学 | Interference type demodulation system and method for large-capacity fiber grating sensor network |
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