CN114370928B - Linear type Sagnac interference type optical fiber vibration sensor - Google Patents
Linear type Sagnac interference type optical fiber vibration sensor Download PDFInfo
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Abstract
The invention provides a linear Sagnac interference type optical fiber vibration sensor, which comprises a light source module, a sensing module, a modulation module, an optical path module and a signal processing module which are connected in sequence; the light source module emits wide-spectrum linearly polarized light, the wide-spectrum linearly polarized light passes through the sensing module, the modulation module and the light path module, and then is reflected by a reflecting mirror at the tail end of the light path module, is interfered at the polarizer, and finally reaches the signal processing module for demodulation; the optical path module comprises a delay optical fiber ring for generating time delay and an optical rotation mirror structure for realizing polarization rotation and inversion; the signal processing module receives the interference signal and demodulates the signal, so that the vibration measurement is finally realized.
Description
Technical Field
The invention relates to the technical field of optical fiber vibration sensing, in particular to a linear Sagnac interference type optical fiber vibration sensor.
Background
Fiber optic sensors have a number of unique advantages over conventional sensors. The sensor network has the advantages of small volume, light weight, electromagnetic interference resistance, corrosion resistance, high sensitivity, wide measurement bandwidth, long interval between detection electronic equipment and a sensor and the like, and can form a sensor network. In particular, the sensitivity is several orders of magnitude higher than that of the conventional sensor, and pressure, temperature, stress (strain), magnetic field, refractive index, deformation, micro vibration, micro displacement, sound pressure and the like can be measured. Fiber optic sagnac (sagnac) interferometers have achieved an unexpected achievement in the practical application of fiber optic gyroscopes and fiber optic current sensors. The Sagnac optical fiber interferometer is a rotatable ring interferometer, which breaks one beam of light emitted by the same light source into two beams, makes the two beams circulate in the same loop in opposite directions for one circle, then meets the two beams, and then generates interference on a screen. The fringe movement in the Sagnac effect is proportional to the product of the angular velocity of the interferometer and the area enclosed by the loop.
The interference type optical fiber vibration sensor changes the phase of light waves in the optical fiber based on the action of vibration to be detected on the sensing optical fiber, and converts the phase change into light intensity change by utilizing an interference technology, so that the vibration signal to be detected is detected and restored. In various interferometer structures, the Sagnac interferometer has the characteristic of dissimilarity, so that the influence of unstable factors caused by interference such as ambient temperature and the like can be avoided. In practical use, a fiber optic gyroscope and a fiber optic current sensor designed based on a sagnac interferometer have become successful commercial sensing devices, and are widely applied to the measurement of angular velocity, ultrasonic waves and current.
The distributed optical fiber sensing technology based on the OFDR technology needs to form a linear sweep-frequency light source by a narrow linewidth single longitudinal mode laser and an electro-optic modulator or an acousto-optic modulator, and has high requirements on the light source. The existing annular Sagnac interference type vibration sensor adopts a mode of two light interference modes of clockwise and anticlockwise propagation, is mostly used for positioning vibration signals, and cannot accurately measure the frequency and the size of the vibration signals; other interferometric vibration sensors can only perform vibration measurements at lower frequencies with less variation, and fail to perform effective measurements for high frequency vibration signals.
Disclosure of Invention
The invention aims to: the invention provides a linear Sagnac interference type optical fiber vibration sensor, which adopts a phase modulator to provide a phase to generate carrier wave so as to realize modulation and demodulation of weak vibration signals, adopts the structure of a linear Sagnac interferometer and uses polarization maintaining optical fiber as sensing optical fiber, and combines a signal processing technology so as to realize high-precision measurement of weak vibration amplitude and frequency, and particularly can effectively measure high-frequency vibration.
The technical scheme of the invention is as follows: in order to achieve the above purpose, the invention adopts the following technical scheme: a linear Sagnac interference type optical fiber vibration sensor comprises a light source module, a sensing module, a modulation module, an optical path module and a signal processing module; the light source module emits wide-spectrum linearly polarized light, the wide-spectrum linearly polarized light passes through the polarization maintaining optical fiber, the sensing module, the modulation module, the optical rotation reflecting mirror and the light path module, and then is reflected by the reflecting mirror at the tail end of the light path module, interferes at the polarizer, and finally reaches the signal processing module for demodulation.
Further, the light source module is used for generating light waves with wide emission spectrum and high output power.
Further, the sensing module is used for receiving the vibration signal for sensing.
Further, the modulation module is used for generating a phase modulation signal and modulating the phase of the optical wave; and phase modulation under different conditions can be achieved by controlling the drive signal.
Further, the optical path module includes two delay coils (delay fiber loops) for generating a time delay, and an optically active mirror structure for achieving polarization rotation and inversion.
Further, the signal processing module converts the optical signal into an electrical signal and demodulates the vibration signal therefrom.
According to the linear Sagnac interference type optical fiber vibration sensing method, light emitted by a light source module is converted into linear polarized light with high extinction ratio through a depolarizer and a polarizer, and then is welded at 45 degrees (two polarization-preserving optical fibers deflect at 45 degrees and are welded again), so that the linear polarized light with two mutually orthogonal polarization directions is decomposed into linear polarized light which is respectively transmitted along the fast axis and the slow axis of the same polarization-preserving optical fiber; the two linearly polarized light beams are subjected to the vibration effect transmitted by the polarization maintaining optical fiber to cause the first vibration phase difference of the two light beams with the fast axis and the slow axis, and then the first modulation phase difference is introduced through the forward modulation effect of the phase modulator of the modulation module; the exchange of the two beams of light of the fast axis and the slow axis is realized through the optical reflector structure; when the backward (reflected) light passes through the same phase modulator, the backward phase modulation is carried out, and the (second) modulation phase difference is introduced again; the reverse light is subjected to the vibration again, and the second phase difference of the two beams of light of the fast axis and the slow axis is caused again; and finally, carrying signals of interference of two beams of polarized light of secondary phase difference and secondary modulation phase difference information caused by vibration at the optical fiber polarizer, and enabling the interfered signals to enter a signal processing module again through a circulator to demodulate vibration signals.
The beneficial effects are that: the invention provides a linear Sagnac interference type optical fiber vibration sensor, which has low requirements on light sources, can realize frequency modulation of megahertz magnitude by using a birefringent phase modulator, can perform good carrier modulation on high-frequency vibration signals, and can also perform good response on changed vibration signals. In addition, the linear Sagnac interference structure is adopted, so that the characteristic of zero optical path difference of the traditional annular Sagnac interferometer is maintained, the noise influence caused by a reference arm is avoided, the system structure is simplified, and the complexity of the system is reduced. In addition, the system adopts the polarization maintaining fiber as the sensing fiber, so that the influence of inherent birefringence of the fiber on measurement is effectively restrained, and the measurement of weak signals is realized.
Drawings
FIG. 1 is a schematic view of a preferred example of a fiber optic vibration sensor provided by the present invention;
FIG. 2a is a waveform diagram of photocurrents at different modulation voltages;
FIG. 2b is a graph of the photocurrent at different modulation voltages;
FIG. 3a is a waveform diagram of photocurrent carrying a vibration signal at a fixed modulation voltage;
FIG. 3b is a graph of the photocurrent carrying the vibration signal at a fixed modulation voltage;
FIG. 4 is a waveform diagram of a demodulated vibration signal;
fig. 5 is a basic structure of a linear sagnac interferometric fiber vibration sensor provided by the invention.
Detailed Description
The invention will be further described with reference to the accompanying drawings. The label specification in the drawings:
1-a light source; 2-a circulator; 3-depolarizer; 4-polarizer; welding at 5-45 degrees; 6-a sensing optical fiber ring; 7-delay coil 1; an 8-phase modulator; 9-a delay coil 2; 10-an optically active mirror; 11-a photodetector; 12-a signal processing unit; 13-vibration signal.
FIG. 5 shows the basic structure of a linear Sagnac interferometric fiber vibration sensor according to the present invention; FIG. 1 is a schematic view of a preferred example of a fiber optic vibration sensor provided by the present invention; the device comprises a light source module, a sensing module, a modulation module, an optical path module and a signal processing module; the light source module emits light waves with wide emission spectrum and high output power, the light waves pass through the sensing module, the modulation module and the light path module, are reflected by the reflecting mirror at the tail end of the light path module, interfere at the polarizer, and finally reach the signal processing module for demodulation.
The light source module comprises a light source (1) for generating light waves with wide emission spectrum and high output power, and can adopt an LD light source, an SLD light source and the like.
The depolarizer (3) changes the light emitted by the light source into unpolarized light after passing through the depolarizer so as to eliminate the polarization influence of the light source. Can adopt the structure of Loyt optical fiber depolarizer, and the ratio of two sections is l 1 :l 2 The polarization maintaining optical fiber with the refractive index spindle rotated by 45 degrees relative to each other is welded by the method of=1:2, and the polarization maintaining optical fiber can also adopt wedge crystal type, periodic piezoelectric ceramic type, coupling ring type and other depolarizer structures.
The polarizer (3) converts unpolarized light into linearly polarized light, and then the linearly polarized light is decomposed into two beams of X-axis (slow axis) and Y-axis (fast axis) light through 45-degree fusion (5). The polarizer can be formed by adopting structures such as an online optical fiber polarizer, a crystal polarizer, a polaroid, a Nicole prism and the like.
The sensing module receives vibration signals by adopting polarization maintaining optical fibers for sensing.
The modulation module adopts a phase modulator (8) to generate a phase modulation signal to modulate the phase of the optical wave; the phase modulation under different conditions can be realized by changing the frequency and the amplitude of the driving signal, and the applied voltage signal and the optical wave phase change are in a direct proportion relation. When the frequency of the signal to be measured is low, the phase modulator can be manufactured by winding the polarization maintaining optical fiber on the piezoelectric ceramic (such as PZT) with voltage application, and the piezoelectric ceramic can generate periodic deformation under the condition of voltage application, so that the polarization maintaining optical fiber wound on the piezoelectric ceramic is deformed, and periodic phase change is generated, thereby realizing phase modulation; when the frequency of the vibration signal to be measured is high, a birefringent phase modulator can be used, and the birefringent phase modulator is required to have the characteristics of high modulation frequency, low insertion loss, low half-wave voltage, low back scattering, wide working wavelength, excellent electro-optic response and the like.
The optical path module comprises a first delay coil 1 (7) before and after a phase modulator,A second delay coil 2 (9), an optically active mirror (10) for generating a time delay and rotationally reflecting the light wave back to the optical path. The total length of the first delay coil 1 and the second delay coil 2 is used for matching the frequency of the vibration signal, the length of the delay coil 2 is used for matching the modulation frequency of the phase modulator, and the delay tau and the frequency omega generated by the delay coil m Needs to meet the requirements ofIn the above, a delay coil of about 850m is required for a vibration frequency of 60 kHz. And (3) carrying out 45-degree counter-shaft fusion on the delay coil 2 (9) and a section of polarization maintaining optical fiber, cutting the length of one quarter beat of the polarization maintaining optical fiber by a movable fixture to obtain a quarter wave plate, and plating a layer of high-reflectivity metal on the end surface of the quarter wave plate to obtain the optical rotation reflecting mirror (10). The second delay coil end is fused to the optical rotatory mirror (10), and a Faraday rotatory mirror may be used as the optical rotatory mirror.
The signal processing module comprises a photoelectric detector (11) and a signal processing unit (12) and is used for receiving the interference signal, converting the optical signal into an electric signal and demodulating the vibration signal.
The Sagnac interference type optical fiber vibration sensor based on the phase generation carrier selects an all-optical fiber type optimal structure, and the working method comprises the following specific processes:
the light source emits high-power light waves with wide spectrums, and unpolarized light is generated through the optical fiber depolarizer so as to eliminate the polarization influence of the light source; the unpolarized light is converted into linear polarized light with high extinction ratio through the optical fiber polarizer, the linear polarized light is decomposed into two beams of linear polarized light with mutually orthogonal polarization directions through a 45-degree fusion point, and the two beams of linear polarized light are respectively transmitted along an X axis (slow axis) and a Y axis (fast axis) of the polarization maintaining optical fiber; when vibration acts on the sensing optical fiber, the phase difference of two beams of light of an X axis (slow axis) and a Y axis (fast axis) is caused, and then the two beams of linearly polarized light are subjected to the forward modulation action of a phase modulator, so that the modulation phase difference is introduced; when the two beams of light pass through a quarter wave plate welded at 45 degrees, the two beams of light are respectively converted into left-handed circularly polarized light and right-handed circularly polarized light, and after the two beams of light are reflected by the end reflector, the left-handed circularly polarized light is converted into right-handed circularly polarized light, and the right-handed circularly polarized light is converted into left-handed circularly polarized light; the reflected two circularly polarized lights return along the original light path, and when the circularly polarized lights pass through the quarter wave plate again, the circularly polarized lights are changed into linearly polarized lights, and the polarization directions of reverse (reflected) light and forward light are interchanged, namely X polarized input light, Y polarized output light, Y polarized input light and X polarized output light; when the reverse light passes through the phase modulator, the reverse light is subjected to backward phase modulation to generate a nonreciprocal phase difference; the reverse light is subjected to the vibration again, so that the phase difference of the two beams of light of the X axis (slow axis) and the Y axis (fast axis) is caused again; finally, two polarized lights carrying phase difference caused by vibration and modulation phase difference information interfere at the optical fiber polarizer and enter a photoelectric detector, and the photoelectric detector converts an optical signal into an electric signal; the photocurrent signal is input to the signal processing unit, thereby demodulating the vibration signal.
Using the jones matrix, the expression for photocurrent can be calculated as:
the use of a Faraday rotator mirrorIn the form of (a). Wherein E is 0 For outputting light intensity phi of light source m Modulated carrier depth, omega, for phase modulator m Is the modulated carrier frequency of the phase modulator,is the phase difference caused by the vibration signal.
Will beExpansion using the Bessel function:
when the vibration signalWhen 0, the drug is added>
As shown in fig. 2a, the photocurrent signal waveforms at different modulation driving voltages are shown without vibration signals. When the driving voltage is continuously increased, the modulation depth of the phase modulator is also continuously increased, and the modulation depth and the driving voltage are in direct proportion.
FIG. 2b is a graph of the signals of FIG. 2a showing the second and fourth harmonics, respectively, of greater signal strength 2h ＝2J 2 (φ m )cos(2ω m t) and I 4h ＝2J 4 (φ m )cos(4ω m t)。
The signal processing unit of the invention can use the phase-locked amplifier to demodulate the signal. Meanwhile, the driving signal of the phase modulator adopts a sine signal provided by a phase-locked amplifier, and the amplitude of the sine signal can be changed in the working voltage range of the phase modulator, so that the phase modulator works at the optimal modulation depth.
Fig. 3a shows the waveform of the photocurrent signal in the presence of the vibration signal, and fig. 3b shows the spectrum of the signal in fig. 3 a.
As can be seen from fig. 3b, the frequency is ω m Carrier signal of =100 kHz and frequency ω v The vibration signal of =48 kHz is mixed, and the mixed signal frequency is omega m +ω v And omega m -ω v The corresponding frequency can be read by utilizing the sweep frequency function of the lock-in amplifier so as to demodulate the frequency omega of the vibration signal v . Will beIn the same way, the second harmonic and the fourth harmonic are I 2h ＝2J 0 (φ v )J 2 (φ m )cos(2ω m t) and I 4h ＝2J 0 (φ v )J 4 (φ m )cos(4ω m t). Measurement with lock-in amplifierThe amplitudes of the two components are divided to obtain +.>Thus, phi can be solved according to the Bessel function m Is substituted into the size of I 2h I or I 4h J can be obtained in 0 (φ v ) Thereby demodulating the amplitude phi of the vibration signal v Finally, the vibration signal can be demodulated>As shown in fig. 4.
In addition, a closed loop feedback system can be used for signal demodulation, and a square wave + step wave closed loop signal modulation scheme can be used for digital signal processing. The square wave modulation is calculated according to the specific modulator, so that the phase modulator generatesSo that the interferometer operates near the point of highest sensitivity on the cosine response curve, the photocurrent at this time can be expressed as +.>Loading the digital step wave signal to a phase modulator to generate a non-reciprocal compensating phase shift phi (t) to cancel out the phase difference generated by the vibration>The interferometer is made to operate always in the vicinity of the position of highest sensitivity, so that the vibration signal is demodulated by detecting the compensation phase shift Φ (t).
In summary, the invention provides a novel Sagnac interference type optical fiber vibration sensor based on phase generation carrier. The implementation way is that a birefringent phase modulator generates a high-frequency phase carrier signal to modulate a weak vibration signal; the polarization maintaining optical fiber is used as the sensing optical fiber, so that the influence of inherent birefringence of the optical fiber on measurement is effectively inhibited; the linear Sagnac interference structure is adopted, so that the linear Sagnac interference structure has the characteristic of zero optical path difference, the noise influence caused by a reference arm is avoided, the measurement of the phase is converted into the measurement of the light intensity, and the system complexity is simplified and the measurement is facilitated.
The foregoing is only a preferred embodiment of the invention, it being noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the present invention, and such modifications and adaptations are intended to be comprehended within the scope of the invention.
Claims (5)
1. The optical fiber vibration sensing method of the linear Sagnac interference type optical fiber vibration sensor is characterized in that the linear Sagnac interference type optical fiber vibration sensor comprises a light source module, a sensing module, a modulation module, an optical path module and a signal processing module which are sequentially connected; the light source module emits wide-spectrum linearly polarized light, the wide-spectrum linearly polarized light passes through the sensing module, the modulation module and the light path module, and then is reflected by a reflecting mirror at the tail end of the light path module, is interfered at the polarizer, and finally reaches the signal processing module for demodulation; the optical path module comprises a first delay coil and a second delay coil for generating time delay, and an optical rotation mirror for realizing polarization rotation and reversal;
the light source module comprises a wide-spectrum light source, a depolarizer and a polarizer and is used for generating linearly polarized light with wide emission spectrum and high output power;
the polarization maintaining optical fiber is used as an optical path optical fiber, a sensing optical fiber ring and a delay coil, and the sensing optical fiber ring is used for receiving vibration signals to sense;
the modulation module is used for generating a phase modulation signal and modulating the phase of the optical wave; and phase modulation can be achieved by controlling the drive signal; the optical path module comprises a depolarizer and a polarizer at the front end, two delay coils for generating time delay and an optical rotation reflector for realizing polarization rotation and reversal; the modulation module generates a phase modulation signal by using a piezoelectric ceramic winding polarization maintaining fiber or a birefringent phase modulator, and modulates the phase of an optical wave; and phase modulation under different conditions is realized by controlling the driving signal;
the signal processing module converts the optical signal into an electric signal and demodulates the vibration signal by using an open loop mode or a closed loop feedback system of the lock-in amplifier;
light emitted by a wide-spectrum light source in the light source module is converted into linear polarized light with high extinction ratio through a depolarizer and a polarizer, and then is welded at 45 degrees to be decomposed into two linear polarized lights with mutually orthogonal polarization directions, and the two linear polarized lights are respectively transmitted along the fast axis and the slow axis of the same polarization-preserving optical fiber; the two linearly polarized light beams are subjected to the vibration effect transmitted by the polarization maintaining optical fiber to cause the first vibration phase difference of the two light beams with the fast axis and the slow axis, and then the first modulation phase difference is introduced through the forward modulation effect of the phase modulator of the modulation module; the exchange and reflection of the two beams of light of the fast axis and the slow axis are realized through the optical reflector; when the reverse light passes through the same phase modulator, the reverse light is subjected to backward phase modulation, and a second modulation phase difference is introduced; the reverse light is subjected to the vibration again, and the second vibration phase difference of the two beams of light of the fast axis and the slow axis is caused again; and finally, carrying signals of interference of two polarized lights of secondary phase difference and secondary modulation phase difference information caused by vibration at the polarizer, and enabling the interfered signals to enter a signal processing module again through the circulator to demodulate vibration signals.
2. The optical fiber vibration sensing method according to claim 1, wherein the phase modulation under different conditions is achieved by changing the frequency and amplitude of the driving signal: when the frequency of the signal to be measured is low, a phase modulator is manufactured by winding a polarization maintaining optical fiber on piezoelectric ceramics with voltage applied; when the frequency of the vibration signal to be measured is high, a birefringent phase modulator is used.
3. The method of claim 1, wherein the optical path module includes a first delay coil positioned before the phase modulator, a second delay coil positioned after the phase modulator, and an optically active mirror to generate a time delay and to rotationally reflect the light wave back to the optical path; the total length of the first delay coil and the second delay coil is used for matching the frequency of the vibration signal, and the length of the second delay coil is used for matching the modulation frequency of the phase modulator; and (3) carrying out 45-degree counter-shaft fusion on the second delay coil and a section of polarization maintaining optical fiber, moving a clamp to intercept the quarter beat length of the polarization maintaining optical fiber to obtain a quarter wave plate, and plating a layer of high-reflectivity metal on the end face of the quarter wave plate to obtain the optical reflection mirror.
4. The method of claim 1, wherein the second delay coil end is fused to the optical rotatory mirror or a faraday rotator mirror is used instead of the optical rotatory mirror.
5. The fiber vibration sensing method of claim 1, wherein the signal processing module uses a lock-in amplifier for signal demodulation; meanwhile, the driving signal of the phase modulator adopts a sine signal provided by a phase-locked amplifier, and the amplitude of the sine signal changes in the working voltage range of the phase modulator.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101465052A (en) * | 2007-12-21 | 2009-06-24 | 陈玉凤 | Safety monitoring system and method for circumference |
| CN102135554A (en) * | 2009-12-10 | 2011-07-27 | 株式会社东芝 | Sagnac interferometer-type fiber-optic current sensor |
| CN102692269A (en) * | 2012-06-13 | 2012-09-26 | 重庆大学 | Positioning method and system of Sagnac fiber distributed vibrating sensor |
| CN102721459A (en) * | 2012-05-29 | 2012-10-10 | 北京航空航天大学 | Optical fiber hydrophone array adopting reflective quasi-reciprocity optical path |
| CN102721458A (en) * | 2012-05-29 | 2012-10-10 | 北京航空航天大学 | Optical fiber hydrophone adopting reflective quasi-reciprocity optical path |
| JP2016085142A (en) * | 2014-10-27 | 2016-05-19 | 日本電信電話株式会社 | Optical fiber vibration sensor and vibration measuring method |
| CN108007572A (en) * | 2017-11-23 | 2018-05-08 | 南京大学 | A kind of rotation disturbance measuring system based on vortex beams and Sa Ge clarke interferometers |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR3034190B1 (en) * | 2015-03-23 | 2019-10-25 | Thales | OPTICAL FIBER SENSOR DISTRIBUTED FROM STRAIN STATE |
-
2022
- 2022-01-12 CN CN202210029997.8A patent/CN114370928B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101465052A (en) * | 2007-12-21 | 2009-06-24 | 陈玉凤 | Safety monitoring system and method for circumference |
| CN102135554A (en) * | 2009-12-10 | 2011-07-27 | 株式会社东芝 | Sagnac interferometer-type fiber-optic current sensor |
| CN102721459A (en) * | 2012-05-29 | 2012-10-10 | 北京航空航天大学 | Optical fiber hydrophone array adopting reflective quasi-reciprocity optical path |
| CN102721458A (en) * | 2012-05-29 | 2012-10-10 | 北京航空航天大学 | Optical fiber hydrophone adopting reflective quasi-reciprocity optical path |
| CN102692269A (en) * | 2012-06-13 | 2012-09-26 | 重庆大学 | Positioning method and system of Sagnac fiber distributed vibrating sensor |
| JP2016085142A (en) * | 2014-10-27 | 2016-05-19 | 日本電信電話株式会社 | Optical fiber vibration sensor and vibration measuring method |
| CN108007572A (en) * | 2017-11-23 | 2018-05-08 | 南京大学 | A kind of rotation disturbance measuring system based on vortex beams and Sa Ge clarke interferometers |
Non-Patent Citations (1)
| Title |
|---|
| 萨格纳克型的光纤振动传感器;曹世才 等;《光学技术》;20190930;第45卷(第5期);第586-589页 * |
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