阅读说明：本技术 用压电陶瓷产生共振频带的光学磁场传感系统 (Optical magnetic field sensing system using piezoelectric ceramic to generate resonance frequency band ) 是由 于长秋 陈志远 马世昌 项晨晨 周铁军 于 2021-08-30 设计创作，主要内容包括：本发明公开了一种用压电陶瓷产生共振频带的光学磁场传感系统,本发明可调谐激光器的发射端、衰减器、偏振控制器、偏振控制器、光纤锥依次相连接,光纤锥与磁场传感系统通过光纤锥锥区处的倏逝波耦合在一起,耦合进入磁场传感系统的光,通过光纤锥耦合出来之后送入光电探测器,并经过T型偏置器分离出交/直流信号,分别送入示波器显示、电谱仪和网络分析仪显示,送入PID控制箱用于将激光器的输出波长；压电陶瓷通过产生频率在空心管腔两个力学模式共振频率中间的超声波,产生共振频带,弥补线宽过窄导致的系统灵敏度随探测频率变化起伏大的缺陷,本发明具备体积小、集成度高、低损耗、低功耗、抗电磁干扰的优点。(The invention discloses an optical magnetic field sensing system for generating a resonance frequency band by using piezoelectric ceramics, wherein a transmitting end of a tunable laser, an attenuator, a polarization controller and an optical fiber cone are sequentially connected, the optical fiber cone and the magnetic field sensing system are coupled together through evanescent waves at a cone area of the optical fiber cone, light entering the magnetic field sensing system is coupled out through the optical fiber cone and then sent to a photoelectric detector, alternating/direct current signals are separated out through a T-shaped biaser and respectively sent to an oscilloscope display, an electric spectrometer and a network analyzer for display, and sent to a PID control box for outputting the wavelength of the laser; the piezoelectric ceramic generates a resonance frequency band by generating ultrasonic waves with the frequency in the middle of two mechanical mode resonance frequencies of the hollow tube cavity, overcomes the defect that the system sensitivity fluctuates greatly along with the change of detection frequency due to the over-narrow line width, and has the advantages of small volume, high integration level, low loss, low power consumption and electromagnetic interference resistance.)

1. An optical magnetic field sensing system using piezoelectric ceramics to generate a resonance frequency band, characterized in that: the device comprises a first signal generator (1), a second signal generator (2), a tunable laser (3), an attenuator (4), a polarization controller (5), an optical fiber cone (6), piezoelectric ceramics (7), a magnetic field sensing system (8), a photoelectric detector (9), a T-shaped biaser (10), an oscilloscope (11), a beam splitter (12), an electric spectrum instrument (13), a network analyzer (14) and a PID control box (15);

the magnetic field sensing system (8) comprises a magnetostrictive medium (16), a hollow tube cavity (17), a bracket (18) and glue (19); the hollow tube cavity is fixed on the bracket by glue, the hollow tube cavity is fixed with the magnetostrictive medium by the glue, and the hollow tube cavity is fixed with the piezoelectric ceramic (7) by the glue;

one path of two paths of signals output by the first signal generator (1) is regulated and controlled by a PID control box (15) and then is sent to a voltage tuning port of the tunable laser (3), and the other path of the two paths of signals is sent to an oscilloscope (11); the second signal generator (2) outputs a signal to the piezoelectric ceramic (7); the light emergent end of the tunable laser (3) is connected with the input end of the attenuator (4), the output end of the attenuator (4) is connected with the input end of the polarization controller (5), and the output end of the polarization controller (5) is connected with the input end of the optical fiber cone (6); the optical field at the cone region of the optical fiber cone (6) enters a hollow tube cavity (17) of a magnetic field sensing system (8) in an evanescent wave coupling mode, the optical field in the hollow tube cavity (17) is coupled and output to a receiving end corresponding to a photoelectric detector (9) through the optical fiber cone (6), a signal output by the photoelectric detector (9) is separated into an alternating current/direct current signal through a T-shaped biaser (10), the direct current signal is sent to an oscilloscope (11) for display, and the alternating current signal is sent to an spectrometer (13), a network analyzer (14) and a PID control box (15) through a beam splitter (12) for signal display and frequency locking; the piezoelectric ceramic is driven by a signal generator through generating signals with corresponding frequencies, and ultrasonic waves with corresponding frequencies are generated, so that the controlled frequency of the ultrasonic waves is in the middle of the resonance frequencies of the two mechanical modes of the hollow cavity, and the resonance frequency band is generated.

2. An optical magnetic field sensing system for generating a resonance frequency band with a piezoelectric ceramic according to claim 1, characterized in that: the frequency of the alternating current magnetic field to be detected and the mechanical mode resonance frequency of the hollow tube cavity in the magnetic field sensing system do not exceed the maximum ultrasonic frequency which can be driven by the piezoelectric ceramic.

3. An optical magnetic field sensing system for generating a resonance frequency band with a piezoelectric ceramic according to claim 1, characterized in that: the piezoelectric ceramic is arranged on a bracket of the magnetic field sensing system and can drive the hollow tube cavity to generate forced vibration; meanwhile, the hollow tube cavity is also acted by a magnetostrictive medium, so that the magnetic field response capability of the hollow tube cavity is ensured; the specific installation position does not need strict requirements, and only needs to meet the use requirements.

4. An optical magnetic field sensing system for generating a resonance frequency band with a piezoelectric ceramic according to claim 1, characterized in that: the hollow pipe cavity (17) is of a hollow structure, the wall thickness is 1 micrometer to 1 millimeter, the outer diameter is 100 micrometers to 5 centimeters, and the specific wall thickness and the specific outer diameter can be determined according to the sensitivity and frequency requirements in the practical application process.

5. An optical magnetic field sensing system for generating a resonance frequency band with a piezoelectric ceramic according to claim 1, characterized in that: the polarization state of the polarization controller is to ensure the highest optical quality factor of the optical mode.

6. An optical magnetic field sensing system for generating a resonance frequency band with a piezoelectric ceramic according to claim 1, characterized in that: the optical fiber is intended to ensure low-loss transmission of optical signals in a selected wavelength band.

7. An optical magnetic field sensing system for generating a resonance frequency band with a piezoelectric ceramic according to claim 1, characterized in that: the attenuator is intended to ensure that the optical power reaching the detector is within the acceptable power range of the detector.

Technical Field

The invention relates to an optical magnetic field sensing system for generating a resonance frequency band by using piezoelectric ceramics, in particular to an optical magnetic field sensing system constructed by the piezoelectric ceramics, a magnetostrictive medium and an optical resonant cavity, and belongs to the field of optics.

Background

The magnetic field sensor is widely applied to the fields of digital economy, transportation, life health, national defense and the like, and the realization mode is diversified. Compared with the existing magnetic field sensing method, the magnetic field sensing technology based on the optical system has the advantages of high speed, strong anti-electromagnetic interference capability and the like. The echo wall is a cavity type which is much researched in recent years, the echo wall mainly utilizes the total internal reflection principle of light, light meeting the conditions can be limited in the microcavity when the phase coherent superposition condition is achieved in the cavity, and the size of the cavity can be compared with the wavelength of light waves. Therefore, the high Q value and the small mode volume can be achieved, the requirement of device integration can be met, and in the whispering gallery mode hollow cavity magnetic field sensing system, the optimal scheme for increasing the sensing sensitivity is that the mechanical mode is close to the frequency of the alternating current magnetic field to be detected to generate resonance. However, since the line width of the frequency spectrum line of the mechanical mode is extremely narrow, when the scheme is applied to the working of a sensing system, if a certain distance exists between the frequency of the alternating current magnetic field to be detected and the frequency of the mechanical mode, the detection sensitivity of the system is reduced, so that the application of the device is limited.

Disclosure of Invention

The invention provides an optical magnetic field sensing system for generating a resonance frequency band by using piezoelectric ceramics aiming at the defects of the prior art, and belongs to the field of optical devices.

The optical magnetic field sensing system generates a resonance frequency band by using piezoelectric ceramics, and the sensing system comprises a first signal generator, a second signal generator, a tunable laser, an attenuator, a polarization controller, an optical fiber cone, the piezoelectric ceramics, a magnetic field sensing system, a photoelectric detector, a T-shaped biaser, an oscilloscope, a beam splitter, an electric spectrometer, a network analyzer and a PID control box; the magnetic field sensing system comprises a magnetostrictive medium, a hollow pipe cavity, a bracket and glue.

One path of two paths of signals output by the first signal generator is regulated and controlled by a PID control box and then is sent to a voltage tuning port of the tunable laser, and the other path of the two paths of signals is sent to an oscilloscope; the second signal generator outputs a signal to the piezoelectric ceramic; the light emergent end of the tunable laser is connected with the input end of the attenuator, the output end of the attenuator is connected with the input end of the polarization controller, and the output end of the polarization controller is connected with the input end of the optical fiber cone; the optical field at the optical fiber cone region enters a hollow tube cavity of the magnetic field sensing system in an evanescent wave coupling mode, the optical field in the hollow tube cavity is coupled and output to a receiving end of a corresponding photoelectric detector through the optical fiber cone, a signal output by the photoelectric detector is separated into an alternating current/direct current signal through a T-shaped biaser, the direct current signal is sent to an oscilloscope for display, the alternating current signal is sent to a spectrometer and a network analyzer for display through the beam splitter, and meanwhile, a signal output by the beam splitter is sent to a PID control box for frequency locking. The hollow tube cavity is fixed on the support through glue, the hollow tube cavity and the magnetostrictive medium are fixed through the glue, and the hollow tube cavity and the piezoelectric ceramic are fixed through the glue.

The tunable laser, the attenuator, the polarization controller, the optical fiber cone and the photoelectric detector in the test sensing system are all connected by optical fibers; the system comprises a first signal generator, a PID control box, a tunable laser, a first signal generator, an oscilloscope, a second signal generator, piezoelectric ceramics, a photoelectric detector, a T-shaped biaser, a beam splitter, an electric spectrometer, a beam splitter, a network analyzer and the PID control box, wherein the PID control box is connected with the tunable laser, the first signal generator, the oscilloscope, the second signal generator, the piezoelectric ceramics, the photoelectric detector, the T-shaped biaser, the oscilloscope, the T-shaped biaser, the beam splitter, the electric spectrometer, the network analyzer and the PID control box through electric cables.

The relative position of the magnetostrictive medium and the hollow tube cavity in the magnetic field sensing system ensures that the magnetostrictive medium can drive the hollow tube cavity to deform when an external magnetic field acts, so that the intensity of transmitted light in the hollow tube cavity is changed; the magnetostrictive medium is Terfenol-D or other medium capable of stretching under the action of a magnetic field.

The piezoelectric ceramic is driven by a signal generator through generating signals with corresponding frequencies, and ultrasonic waves with corresponding frequencies are generated, so that the controlled frequency of the ultrasonic waves is in the middle of the resonance frequencies of the two mechanical modes of the hollow cavity, and the resonance frequency band is generated.

Preferably, the hollow tube cavity is of a hollow structure, the wall thickness is micrometer-millimeter, the outer diameter is micrometer-centimeter, and the specific wall thickness and the outer diameter can be determined according to the sensitivity requirement in the practical application process, but the resonance frequency of the mechanical mode of the hollow tube cavity is ensured not to exceed the maximum ultrasonic frequency which can be generated by the piezoelectric ceramic.

Preferably, the positions of the piezoelectric ceramic and the magnetostrictive medium can be changed. But the vibration damping effect and the stress of the magnetostrictive medium on the hollow pipe cavity are ensured.

Preferably, the optical fiber is configured to ensure low loss transmission of optical signals within the selected wavelength band.

Preferably, the polarization state of the polarization controller is such that the optical quality factor of the optical mode is highest.

Preferably, the attenuator is arranged to ensure that the optical power reaching the detector is within the acceptable power range of the detector.

The sensing system can perform high-sensitivity magnetic field sensing and has good stability, and meanwhile, the transmitted signal has the capability of resisting external interference. In addition, the system is mainly constructed by optical fibers, has small volume and easy integration, and can be used for remotely detecting magnetic field information.

Drawings

FIG. 1 is a schematic diagram of an optical magnetic field sensing system using piezoelectric ceramics to generate resonance frequency band.

Detailed Description

The essential features and the remarkable advantages of the present invention will be further clarified by the following embodiments, but the contents of the present invention are not limited to the following embodiments:

the first embodiment is as follows: as shown in fig. 1, two paths of signals output by a first signal generator 1 described in the optical magnetic field sensing system for generating a resonance frequency band by using piezoelectric ceramics according to the present embodiment are regulated by a PID control box 15, one path of the signals is sent to a voltage tuning port of a tunable laser 3, and the other path of the signals is sent to an oscilloscope 11; the second signal generator 2 outputs a signal to the piezoelectric ceramics 7; the light emergent end of the tunable laser 3 is connected with the input end of an attenuator 4, the output end of the attenuator 4 is connected with the input end of a polarization controller 5, and the output end of the polarization controller 5 is connected with the input end of an optical fiber cone 6; an optical field at the conical area of the optical fiber cone 6 enters a hollow tube cavity of the magnetic field sensing system 8 in an evanescent wave coupling mode, the optical field in the hollow tube cavity is coupled and output to a receiving end corresponding to the photoelectric detector 9 through the optical fiber cone 6, an output port of the photoelectric detector 9 is connected with a T-shaped biaser 10, the T-shaped biaser 10 is respectively connected with an oscilloscope 11 and a beam splitter 12, and the beam splitter 12 is connected with an electric spectrum instrument 13, a network analyzer 14 and a PID control box 15. And then obtaining a mechanical mode spectral line of the magnetic field sensing system by an electric spectrometer under the condition of no alternating current magnetic field to be detected, then opening the piezoelectric ceramic 7 after finding a target formant, and setting the working frequency of the piezoelectric ceramic between the two formant frequencies. When the alternating current magnetic field to be detected appears and the working frequency is in the resonant frequency band, the system can be used for detecting the alternating current magnetic field with high sensitivity.