WO2017016144A1 - Displacement sensor, method of use and manufacture thereof, and interferometer - Google Patents

Displacement sensor, method of use and manufacture thereof, and interferometer Download PDF

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WO2017016144A1
WO2017016144A1 PCT/CN2015/097620 CN2015097620W WO2017016144A1 WO 2017016144 A1 WO2017016144 A1 WO 2017016144A1 CN 2015097620 W CN2015097620 W CN 2015097620W WO 2017016144 A1 WO2017016144 A1 WO 2017016144A1
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Prior art keywords
diffracted light
light
diffraction grating
displacement sensor
diffracted
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PCT/CN2015/097620
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French (fr)
Chinese (zh)
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孙天玉
张宝顺
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中国科学院苏州纳米技术与纳米仿生研究所
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Publication of WO2017016144A1 publication Critical patent/WO2017016144A1/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—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
    • 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
    • G01D5/34—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
    • G01D5/36—Forming the light into pulses
    • G01D5/38—Forming the light into pulses by diffraction gratings
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P13/00—Indicating or recording presence, absence, or direction, of movement

Definitions

  • the present invention relates to the field of Micro Optic Electro Mechanical System (MOEMS) technology, and more particularly to a displacement sensor.
  • MOEMS Micro Optic Electro Mechanical System
  • Displacement refers to the offset of the position of the object relative to the reference point.
  • the displacement is easy to detect and easy to obtain high-precision detection results compared with other quantities. Therefore, the mechanical quantity of the measured object is often converted into The amount of displacement is detected.
  • the acceleration is converted into a displacement of the mass
  • the expansion is converted into a displacement of the surface of the object, and the like.
  • Small displacement measurement is the basis of measurement techniques such as pressure, acceleration, flow, temperature, and vibration.
  • Large displacement measurement is the basis of automated production lines (such as robot movement), industrial inspection (such as expansion), and online monitoring (such as vibration).
  • the photoelectric displacement sensor converts the displacement information into optical information and is reflected by the light intensity detected by the photodiode.
  • Photoelectric displacement sensors have been widely studied and applied for their non-contact measurement, fast test speed, high precision and small test points.
  • the existing photoelectric displacement tests mainly include laser triangulation, Moire fringe method, double beam interferometry, dual-frequency laser interferometry based on Doppler effect, etc., which are mostly used for measurement of large displacement, and their optical path systems are also It is more complicated and cannot meet the requirements of small size, easy integration, high reliability and low power consumption in modern industrial development.
  • the two-beam interferometry is based on a Michelson interferometer, which uses information about the change in the interference intensity of the two beams to reflect the amount of displacement.
  • the displacement information of the object to be measured is inferred from the interference intensity.
  • the sinusoidal phase modulation method can make the displacement measurement accuracy reach more than one percent of the wavelength of the detection light.
  • the coherence length of the source determines the maximum measurable range.
  • the light source is mostly provided by a He-Ne laser, but the body of the He-Ne laser itself. The larger the product, which fundamentally affects the volume of the large displacement two-beam interferometry system.
  • embodiments of the present invention are expected to provide a displacement sensor and an interferometer that are characterized by miniaturization, ease of integration, high reliability, and low power consumption.
  • the embodiment of the invention provides a displacement sensor, and the displacement sensor comprises:
  • a diffraction grating for directly diffracting and reflecting a part of the light of the laser beam to generate a first diffracted light; and simultaneously for passing the laser beam through itself, reaching an object to be measured, and reflecting the object to be tested Diffracting a portion of the light again through itself to form a second diffracted light;
  • a detector located at the intersection of the diffracted lights of the first order of the first diffracted light and the second diffracted light, for measuring between the first diffracted light and the second diffracted light The change in the interference intensity information
  • An information processor connected to the detector, for reading an interference intensity signal, and inverting displacement information of the object to be tested according to the interference intensity change information detected by the detector;
  • the diffraction grating is located between the semiconductor laser and the object to be tested.
  • the displacement sensor further includes:
  • a diffraction grating modulation and demodulation device for introducing periodic vibration to the diffraction grating and demodulating the interference intensity information detected by the detector.
  • the displacement sensor further includes:
  • the reflected light collecting device is configured to collect the light reflected by the object to be measured, so that the detected second diffracted light has the same intensity as the diffracted light of the first order of the first diffracted light.
  • the semiconductor laser is a long coherence distance semiconductor laser.
  • the invention also provides an interferometer comprising:
  • a diffraction grating for directly diffracting and reflecting a part of the light of the laser beam to generate a first diffracted light; and simultaneously for passing the laser beam through itself, reaching an object to be measured, and reflecting the object to be tested Diffracting a portion of the light again through itself to form a second diffracted light;
  • a detector located at the intersection of the diffracted lights of the first order of the first diffracted light and the second diffracted light, for measuring between the first diffracted light and the second diffracted light The change in the interference intensity information.
  • the interferometer further includes:
  • a diffraction grating modulation and demodulation device for introducing periodic vibration to the diffraction grating and demodulating the interference intensity information detected by the detector.
  • the interferometer further includes:
  • the reflected light collecting device is configured to collect the light reflected by the object to be measured, so that the detected second diffracted light has the same intensity as the diffracted light of the first order of the first diffracted light.
  • the semiconductor laser is a long coherence distance semiconductor laser.
  • the invention also provides a method of using a displacement sensor, the method comprising:
  • a semiconductor laser generates a laser beam
  • the diffraction grating directly diffracts and reflects a part of the light of the laser beam to generate a first diffracted light; at the same time, the diffraction grating passes the laser beam through itself, reaches an object to be measured, and passes through the object to be measured to pass through again. a part of the light of itself, diffracted into the second diffracted light;
  • the detector measures a change in interference intensity information between the first diffracted light and the diffracted light of the second order of the second diffracted light;
  • the information processor reads the interference intensity signal and inverts the displacement information of the object to be tested according to the interference intensity change information detected by the detector.
  • the invention also provides a method for manufacturing a displacement sensor, the method comprising:
  • All or part of the semiconductor laser, the diffraction grating, the photodetector, the information processor, and the grating modulation device, the MOEMS element of the reflected light collecting device are integrated into one single piece.
  • the probe light of the displacement sensor provided by the present invention can be provided by a long coherence distance semiconductor laser, unlike the existing dual beam displacement measurement system, and the probe light is provided by a He-Ne laser or the like.
  • the displacement sensor thus invented has the characteristics of miniaturization and easy integration.
  • the maximum range measured by the sensor is half the coherence distance of the semiconductor laser. With the continuous advancement of the long coherence distance semiconductor laser technology, the range of the invented displacement sensor can reach several meters or more.
  • the method of generating the coherent double beam is not realized by using different optical paths like the Michelson interferometer, but by using the semi-transverse property of the diffraction grating to achieve the splitting.
  • the direct reflection of the grating and the surface reflection of the object to be measured provide two coherent lights whose optical path difference contains the displacement information of the object to be measured.
  • the two beams that interfere with each other may be diffracted light of any one of the first diffracted light and the second diffracted light, such as 0th order, ⁇ 1 order, ⁇ 2 order, etc., and their spatial directions are different, so different levels of diffracted light are utilized.
  • the spatial position of the corresponding detector is also different.
  • a modulation system can be introduced to the diffraction grating. Periodic vibration is introduced into the diffraction grating, and then the interference intensity information detected by the detector is demodulated; this can effectively suppress and reduce noise and improve measurement accuracy.
  • the components of the displacement sensor and the interferometer provided by the present invention can utilize the MOEMS work.
  • the art production therefore, makes the displacement sensor and the interferometer provided by the invention have the characteristics of miniaturization and easy integration.
  • FIG. 1 is a schematic structural diagram of a displacement sensor according to an embodiment of the present invention.
  • FIG. 2 is a schematic flow chart of a method for using a displacement sensor according to an embodiment of the present invention
  • FIG. 3 is a schematic diagram of light propagation during operation of a displacement sensor according to an embodiment of the present invention.
  • FIG. 1 is a schematic structural diagram of a displacement sensor according to an embodiment of the present invention. As shown in FIG. 1 , the displacement sensor includes:
  • a diffraction grating 102 for directly diffracting and reflecting a part of the light of the laser beam to generate a first diffracted light; and simultaneously for passing the laser beam through itself, reaching an object to be measured, and reflecting by the object to be tested After that, a part of the light is again diffracted through itself to form a second diffracted light;
  • the detector 103 is located at the intersection of the diffracted lights of the first order of the first diffracted light and the second diffracted light, and is used for measuring the diffracted light of the first order of the first diffracted light and the second diffracted light. Change in interference intensity information;
  • the information processor 104 is connected to the detector for reading the interference intensity signal, and inverting the displacement information of the object to be tested according to the interference intensity change information detected by the detector;
  • the diffraction grating is located between the semiconductor laser and the object to be tested.
  • the semiconductor laser 101 may be a long coherence distance semiconductor laser, so that the displacement sensor can measure a large displacement, and the range of the displacement sensor is half of the coherence distance of the semiconductor laser, with long coherence
  • the range of the displacement sensor invented can reach several meters or more.
  • the diffraction grating 102 may be implemented as a grating that is transflective to the laser light.
  • the detector 103 may be a photodetector; the position of the detector 103 is the wavelength of the laser light emitted from the semiconductor laser 101, the period of the diffraction grating 102, and the diffracted light to be measured to interfere.
  • the position of the detector 103 is the wavelength of the laser light emitted from the semiconductor laser 101, the period of the diffraction grating 102, and the diffracted light to be measured to interfere.
  • the position of the detector is determined by the direction of the diffraction order to be measured and the distance between the detection surface and the diffraction grating. . Therefore, it is necessary to preset which level of diffracted light is specifically measured. In practical applications, it can be set to 0, ⁇ 1, ⁇ 2, etc. according to the specific situation, that is, the diffracted light of the same order of the above-mentioned preset can be It is a class 0, ⁇ 1 level, ⁇ 2 level diffracted light.
  • the information processor 104 may be in a practical application by a central processing unit (CPU), a microprocessor (MPU), a digital signal processor (DSP), or a field programmable gate array located in the displacement sensor. (FPGA) implementation.
  • CPU central processing unit
  • MPU microprocessor
  • DSP digital signal processor
  • FPGA field programmable gate array
  • the above displacement sensor may further include:
  • the diffraction grating modulation and demodulation device 105 is configured to introduce periodic vibration to the diffraction grating and demodulate the interference intensity information detected by the detector.
  • the diffraction grating modulation and demodulation device 105 can be implemented by a method such as piezoelectric modulation.
  • the purpose of the diffraction grating modulation and demodulation device is to suppress noise during measurement, and it can be implemented by means of phase lock amplification in a small signal processing. Improve the signal-to-noise ratio of the detection signal to improve the accuracy of the displacement measurement.
  • the above displacement sensor may further include:
  • the reflected light collecting device 106 is configured to collect the light reflected by the object to be tested, so that the detected second diffracted light has the same intensity as the diffracted light of the first order of the first diffracted light.
  • the reflected light collecting device 106 can be implemented by a lens or the like.
  • the purpose of the reflected light collecting device 106 is to cause more light reflected by the object to be measured to participate in coherence. Ideally, the intensity of the two beams participating in the coherence is equal.
  • the present invention also provides an interferometer comprising:
  • a diffraction grating for directly diffracting and reflecting a part of the light of the laser beam to generate a first diffracted light; and simultaneously for passing the laser beam through itself, reaching an object to be measured, and reflecting the object to be tested Diffracting a portion of the light again through itself to form a second diffracted light;
  • a detector located at the intersection of the diffracted lights of the first order of the first diffracted light and the second diffracted light, for measuring between the first diffracted light and the second diffracted light The change in the interference intensity information.
  • the interferometer further includes:
  • a diffraction grating modulation and demodulation device for introducing periodic vibration to the diffraction grating and demodulating the interference intensity information detected by the detector.
  • the interferometer further includes:
  • the reflected light collecting device is configured to collect the light reflected by the object to be measured, so that the detected second diffracted light has the same intensity as the diffracted light of the first order of the first diffracted light.
  • the semiconductor laser is a long coherence distance semiconductor laser.
  • FIG. 2 is a schematic flow chart of a method for using the above displacement sensor according to the present invention. As shown in FIG. 2, the method includes:
  • Step 201 the semiconductor laser generates a laser beam
  • Step 202 The diffraction grating directly diffracts and reflects a part of the light of the laser beam to generate a first diffracted light; and the diffraction grating passes the laser beam through itself, reaches an object to be tested, and is reflected by the object to be tested. Diffracting a portion of the light again through itself to form a second diffracted light;
  • the first diffracted light includes a series of diffraction orders.
  • a part of the laser beam passes through the diffraction grating to reach the object to be measured, is reflected by the object to be measured, and then diffracted into the second diffracted light through the diffraction grating through the reflected light collecting device.
  • the second diffracted light also contains a series of diffraction orders, such as 0, ⁇ 1, ⁇ 2, and the like.
  • Step 203 The detector measures a change in interference intensity information between the first diffracted light and the diffracted light of the second order of the second diffracted light.
  • the diffraction grating is adjusted such that the reflection surface of the object to be measured is parallel to the reflection surface of the grating, as shown in FIG. 3, and the space of the diffracted light of the same diffraction order preset in the first diffracted light and the second diffracted light at this time The directions are the same and they will interfere.
  • the detector is adjusted such that the detector is located at the intersection of the same diffraction orders preset in the first diffracted light and the second diffracted light, as shown in FIG. In this way, the detector can measure the change information of the interference intensity between the first diffracted light and the second diffracted light.
  • the predetermined same diffraction order means that the order of the first diffracted light and the second diffracted light is 0, the same as ⁇ 1, and the same as ⁇ 2.
  • the diffraction grating can be introduced into the diffraction grating by the diffraction grating modulation and demodulation device, and the interference intensity change information detected by the detector can be demodulated to suppress noise during the measurement process.
  • Step 204 The information processor reads the interference intensity signal, and inverts the displacement information of the object to be tested according to the interference intensity change information detected by the detector;
  • the optical path difference between the first diffracted light and the second diffracted light that interferes at this time is determined by the distance between the reflective surface of the diffraction grating and the reflective surface of the object to be measured, and thus The method of measuring the displacement information by the Michelson interferometer is the same.
  • the information processor can reverse the displacement information of the moving object after passing through the existing processing circuit and executing the existing processing algorithm.
  • the invention also provides a method for manufacturing the above displacement sensor, the method comprising:
  • All or part of the semiconductor laser, the diffraction grating, the photodetector, the information processor, and the grating modulation device, the MOEMS element of the reflected light collecting device are integrated into one single piece.
  • a separate semiconductor laser, a diffraction grating, a grating modulation device, a reflected light collecting device, a photodetector, an information processor, and the like are assembled with reference to FIG. 1 to constitute the inventive displacement sensor; or
  • MOEMS component of the reflected light collecting device into a single chip, to make a fully integrated Or semi-integrated MOEMS displacement sensor.
  • the probe light of the displacement sensor provided by the present invention can be provided by a long coherence distance semiconductor laser, unlike the existing dual beam displacement measurement system, and the probe light is provided by a He-Ne laser or the like.
  • the displacement sensor thus invented has the characteristics of miniaturization and easy integration.
  • the maximum range measured by the sensor is half the coherence distance of the semiconductor laser. With the continuous advancement of the long coherence distance semiconductor laser technology, the range of the invented displacement sensor can reach several meters or more.
  • the method of generating the coherent double beam is not realized by using different optical paths like the Michelson interferometer, but by using the semi-transverse property of the diffraction grating to achieve the splitting.
  • the direct reflection of the grating and the surface reflection of the object to be measured provide two coherent lights whose optical path difference contains the displacement information of the object to be measured.
  • the two beams that interfere with each other may be diffracted light of any one of the first diffracted light and the second diffracted light, such as 0th order, ⁇ 1 order, ⁇ 2 order, etc., and their spatial directions are different, so different levels of diffracted light are utilized.
  • the spatial position of the corresponding detector is also different.
  • a modulation system can be introduced to the diffraction grating. Periodic vibration is introduced into the diffraction grating, and then the interference intensity information detected by the detector is demodulated; this can effectively suppress and reduce noise and improve measurement accuracy.
  • the invented displacement sensor In terms of manufacturing method, it can be built by separate component patches or integrated. When the separated component patches are constructed, separate semiconductor lasers, diffraction gratings, grating modulation devices, reflected light collecting devices, photodetectors, information processors, and the like are assembled with reference to FIG. 1 to constitute the inventive displacement sensor. Since the components of the invented displacement sensor are manufactured to be compatible with existing MOEMS processes, a single integrated displacement sensor can be fabricated using all MOEMS processes.

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Abstract

Provided is a displacement sensor, comprising: a semiconductor laser (101) for generating a laser beam; a diffraction grating (102) for directly diffracting and then reflecting a portion of light in the laser beam to generate a first diffracted light, and for diffracting a portion of light in the laser beam passing through the diffraction grating, reaching an object to be measured, and passing through the diffraction grating again after being reflected by the object, so as to form a second diffracted light; a detector (103), located at an intersection of diffracted lights having a preset same order in the first diffracted light and the second diffracted light to be measured, and being for measuring an interference intensity information variation between the diffracted lights; and an information processor (104), connected to the detector (103), and being for reading an interference intensity signal, and for inverting, according to the interference intensity variation information measured by the detector (103), displacement information of the object, wherein the diffraction grating (102) is located between the semiconductor laser (101) and the object. Further disclosed are methods of use and manufacture of the displacement sensor, and an interferometer.

Description

一种位移传感器及其使用、制作方法和一种干涉仪Displacement sensor and use thereof, manufacturing method and interferometer 技术领域Technical field
本发明涉及微光机电系统(Micro Optic Electro Mechanical System，MOEMS)技术领域，尤其涉及一种位移传感器。The present invention relates to the field of Micro Optic Electro Mechanical System (MOEMS) technology, and more particularly to a displacement sensor.
背景技术Background technique
位移是指物体位置相对参考点产生的偏移量，在众多的物理量中位移与其它量相比是既容易检测又容易获得高精度的检测结果，所以测量中常将被测对象的机械量转换成位移量来检测。例如将加速度转换成质量块的位移、将膨胀转换成物体表面的位移等。小位移测量是压力、加速度、流量、温度、振动等测量技术的基础，大位移测量是自动化生产线(如机械手的移动)、工业检测(如膨胀)、在线监控(如振动)等的根基。Displacement refers to the offset of the position of the object relative to the reference point. In many physical quantities, the displacement is easy to detect and easy to obtain high-precision detection results compared with other quantities. Therefore, the mechanical quantity of the measured object is often converted into The amount of displacement is detected. For example, the acceleration is converted into a displacement of the mass, the expansion is converted into a displacement of the surface of the object, and the like. Small displacement measurement is the basis of measurement techniques such as pressure, acceleration, flow, temperature, and vibration. Large displacement measurement is the basis of automated production lines (such as robot movement), industrial inspection (such as expansion), and online monitoring (such as vibration).
光电位移传感器将位移信息转化为光学信息，并通过光电二极管探测到的光强体现出来。光电位移传感器具有非接触测量、测试速度快、精度高、测试点小等优点被广泛研究和应用。现有的光电位移测试主要有激光三角测量法、莫尔条纹法、双光束干涉法、基于多普勒效应的双频激光干涉法等，它们大都用于大位移的测量，其光路系统也都比较复杂，无法满足现代工业发展中小体积、易集成、高可靠性、低功耗要求。The photoelectric displacement sensor converts the displacement information into optical information and is reflected by the light intensity detected by the photodiode. Photoelectric displacement sensors have been widely studied and applied for their non-contact measurement, fast test speed, high precision and small test points. The existing photoelectric displacement tests mainly include laser triangulation, Moire fringe method, double beam interferometry, dual-frequency laser interferometry based on Doppler effect, etc., which are mostly used for measurement of large displacement, and their optical path systems are also It is more complicated and cannot meet the requirements of small size, easy integration, high reliability and low power consumption in modern industrial development.
双光束干涉测量法基于迈克尔逊干涉仪、用双光束干涉强度的变化来反映位移量的信息。由干涉强度反演被测对象的位移信息已被广泛地研究，利用正弦相位调制法可使位移测量精度达到检测光波长的百分之一以上。在双光束干涉测量系统中，光源的相干长度决定了可测量的最大量程。现有的大量程的双光束干涉测量系统中光源大都由He-Ne激光器提供，但He-Ne激光器本身的体 积较大，这从根本上影响大位移双光束干涉测量系统的体积。The two-beam interferometry is based on a Michelson interferometer, which uses information about the change in the interference intensity of the two beams to reflect the amount of displacement. The displacement information of the object to be measured is inferred from the interference intensity. The sinusoidal phase modulation method can make the displacement measurement accuracy reach more than one percent of the wavelength of the detection light. In a two-beam interferometry system, the coherence length of the source determines the maximum measurable range. In the existing large-range dual-beam interferometry system, the light source is mostly provided by a He-Ne laser, but the body of the He-Ne laser itself. The larger the product, which fundamentally affects the volume of the large displacement two-beam interferometry system.
发明内容Summary of the invention
为解决现有存在的技术问题，本发明实施例期望提供一种具有微型化、易集成、高可靠性和低功耗等特点的位移传感器和干涉仪。In order to solve the existing technical problems, embodiments of the present invention are expected to provide a displacement sensor and an interferometer that are characterized by miniaturization, ease of integration, high reliability, and low power consumption.
本发明实施例的技术方案是这样实现的：The technical solution of the embodiment of the present invention is implemented as follows:
本发明实施例提供一种位移传感器，该位移传感器包括：The embodiment of the invention provides a displacement sensor, and the displacement sensor comprises:
半导体激光器，用于产生激光光束；a semiconductor laser for generating a laser beam;
衍射光栅，用于将所述激光光束中的一部分光直接衍射再反射，产生第一衍射光；同时用于将所述激光光束中穿过自身、到达待测物体，并经待测物体反射后再次穿过自身的一部分光衍射，形成第二衍射光；a diffraction grating for directly diffracting and reflecting a part of the light of the laser beam to generate a first diffracted light; and simultaneously for passing the laser beam through itself, reaching an object to be measured, and reflecting the object to be tested Diffracting a portion of the light again through itself to form a second diffracted light;
探测器，位于待测第一衍射光和第二衍射光中预设相同级次的衍射光交汇处，用于测量第一衍射光与第二衍射光中预设相同级次的衍射光之间的干涉强度信息的变化；a detector, located at the intersection of the diffracted lights of the first order of the first diffracted light and the second diffracted light, for measuring between the first diffracted light and the second diffracted light The change in the interference intensity information;
信息处理器，与所述探测器相连，用于读取干涉强度信号，根据探测器探测的干涉强度变化信息，反演出待测物体的位移信息；An information processor, connected to the detector, for reading an interference intensity signal, and inverting displacement information of the object to be tested according to the interference intensity change information detected by the detector;
所述衍射光栅位于半导体激光器与待测物体之间。The diffraction grating is located between the semiconductor laser and the object to be tested.
上述方案中，所述位移传感器还包括：In the above solution, the displacement sensor further includes:
衍射光栅调制解调装置，用于对衍射光栅引入周期性的振动，以及对探测器探测到的干涉强度信息进行解调。A diffraction grating modulation and demodulation device for introducing periodic vibration to the diffraction grating and demodulating the interference intensity information detected by the detector.
上述方案中，所述位移传感器还包括：In the above solution, the displacement sensor further includes:
反射光收集装置，用于收集经待测物体反射的光，使得所探测第二衍射光与第一衍射光中预设相同级次的衍射光的强度相当。The reflected light collecting device is configured to collect the light reflected by the object to be measured, so that the detected second diffracted light has the same intensity as the diffracted light of the first order of the first diffracted light.
上述方案中，所述半导体激光器为长相干距离半导体激光器。 In the above solution, the semiconductor laser is a long coherence distance semiconductor laser.
本发明还提供一种干涉仪，该干涉仪包括：The invention also provides an interferometer comprising:
半导体激光器，用于产生激光光束；a semiconductor laser for generating a laser beam;
衍射光栅，用于将所述激光光束中的一部分光直接衍射再反射，产生第一衍射光；同时用于将所述激光光束中穿过自身、到达待测物体，并经待测物体反射后再次穿过自身的一部分光衍射，形成第二衍射光；a diffraction grating for directly diffracting and reflecting a part of the light of the laser beam to generate a first diffracted light; and simultaneously for passing the laser beam through itself, reaching an object to be measured, and reflecting the object to be tested Diffracting a portion of the light again through itself to form a second diffracted light;
探测器，位于待测第一衍射光和第二衍射光中预设相同级次的衍射光交汇处，用于测量第一衍射光与第二衍射光中预设相同级次的衍射光之间的干涉强度信息的变化。a detector, located at the intersection of the diffracted lights of the first order of the first diffracted light and the second diffracted light, for measuring between the first diffracted light and the second diffracted light The change in the interference intensity information.
上述方案中，所述干涉仪还包括：In the above solution, the interferometer further includes:
衍射光栅调制解调装置，用于对衍射光栅引入周期性的振动，以及对探测器探测到的干涉强度信息进行解调。A diffraction grating modulation and demodulation device for introducing periodic vibration to the diffraction grating and demodulating the interference intensity information detected by the detector.
上述方案中，所述干涉仪还包括：In the above solution, the interferometer further includes:
反射光收集装置，用于收集经待测物体反射的光，使得所探测第二衍射光与第一衍射光中预设相同级次的衍射光的强度相当。The reflected light collecting device is configured to collect the light reflected by the object to be measured, so that the detected second diffracted light has the same intensity as the diffracted light of the first order of the first diffracted light.
上述方案中，所述半导体激光器为长相干距离半导体激光器。In the above solution, the semiconductor laser is a long coherence distance semiconductor laser.
本发明还提供一种位移传感器的使用方法，该方法包括：The invention also provides a method of using a displacement sensor, the method comprising:
半导体激光器产生激光光束；a semiconductor laser generates a laser beam;
衍射光栅将所述激光光束中的一部分光直接衍射再反射，产生第一衍射光；同时衍射光栅将所述激光光束中穿过自身、到达待测物体，并经待测物体反射后再次穿过自身的一部分光，衍射为第二衍射光；The diffraction grating directly diffracts and reflects a part of the light of the laser beam to generate a first diffracted light; at the same time, the diffraction grating passes the laser beam through itself, reaches an object to be measured, and passes through the object to be measured to pass through again. a part of the light of itself, diffracted into the second diffracted light;
探测器测量第一衍射光与第二衍射光中预设相同级次的衍射光之间的干涉强度信息的变化； The detector measures a change in interference intensity information between the first diffracted light and the diffracted light of the second order of the second diffracted light;
信息处理器读取干涉强度信号，根据探测器探测的干涉强度变化信息，反演出待测物体的位移信息。The information processor reads the interference intensity signal and inverts the displacement information of the object to be tested according to the interference intensity change information detected by the detector.
本发明还提供一种位移传感器的制作方法，该方法包括：The invention also provides a method for manufacturing a displacement sensor, the method comprising:
使用微光机电系统MOEMS工艺生产半导体激光器、衍射光栅、探测器、信息处理器，以及光栅调制装置、反射光收集装置的MOEMS元件；Production of semiconductor lasers, diffraction gratings, detectors, information processors, and MOEMS components of grating modulation devices and reflected light collection devices using a micro-optical electromechanical system MOEMS process;
将分离的半导体激光器、衍射光栅、光电探测器、信息处理器，以及光栅调制装置、反射光收集装置的MOEMS元件按照根据上述任意一种位移传感器结构组装；或者Separating the semiconductor laser, the diffraction grating, the photodetector, the information processor, and the MOEMS element of the grating modulation device and the reflected light collecting device according to any one of the above displacement sensor structures; or
将半导体激光器、衍射光栅、光电探测器、信息处理器，以及光栅调制装置、反射光收集装置的MOEMS元件中的全部或部分元件集成于一个单片中。All or part of the semiconductor laser, the diffraction grating, the photodetector, the information processor, and the grating modulation device, the MOEMS element of the reflected light collecting device are integrated into one single piece.
上述的技术方案的特点是：本发明提供的位移传感器的探测光可由长相干距离半导体激光器提供，并不像现有的双光束位移测量系统，探测光由He-Ne激光器等提供。这样所发明的位移传感器具有微型化、易集成等特点。传感器所测量的最大量程是半导体激光器相干距离的一半，随着长相干距离半导体激光器技术的不断进步，所发明的位移传感器的量程可以达到数米甚至更远。The above technical solution is characterized in that the probe light of the displacement sensor provided by the present invention can be provided by a long coherence distance semiconductor laser, unlike the existing dual beam displacement measurement system, and the probe light is provided by a He-Ne laser or the like. The displacement sensor thus invented has the characteristics of miniaturization and easy integration. The maximum range measured by the sensor is half the coherence distance of the semiconductor laser. With the continuous advancement of the long coherence distance semiconductor laser technology, the range of the invented displacement sensor can reach several meters or more.
上述技术方案的另外一个特点是：产生相干双光束的方法并不是像迈克尔逊干涉仪那样利用不同的光路来实现，而是利用衍射光栅的半反半透性质来实现分光的。光栅的直接反射和待测物体的表面反射提供了两束相干光，它们的光程差包含了待测物体的位移信息。相互干涉的两束光可以是第一衍射光与第二衍射光中任何一级的衍射光，如0级，±1级，±2级等，它们的空间方向不同，因此利用不同级别衍射光相干信息测量时，相应探测器的空间位置也不同。Another feature of the above technical solution is that the method of generating the coherent double beam is not realized by using different optical paths like the Michelson interferometer, but by using the semi-transverse property of the diffraction grating to achieve the splitting. The direct reflection of the grating and the surface reflection of the object to be measured provide two coherent lights whose optical path difference contains the displacement information of the object to be measured. The two beams that interfere with each other may be diffracted light of any one of the first diffracted light and the second diffracted light, such as 0th order, ±1 order, ±2 order, etc., and their spatial directions are different, so different levels of diffracted light are utilized. When the coherent information is measured, the spatial position of the corresponding detector is also different.
上述的技术方案的另外一个特点是：可以对衍射光栅引入调制系统。对衍射光栅引入周期性的振动，而后对探测器探测到的干涉强度信息进行解调；这样可以有效地抑制和降低噪声，提高测量精度。Another feature of the above technical solution is that a modulation system can be introduced to the diffraction grating. Periodic vibration is introduced into the diffraction grating, and then the interference intensity information detected by the detector is demodulated; this can effectively suppress and reduce noise and improve measurement accuracy.
此外，本发明提供的位移传感器和干涉仪的各个组件都可利用MOEMS工 艺生产，因此，使得本发明提供的位移传感器和干涉仪具有微型化、易集成的特点。In addition, the components of the displacement sensor and the interferometer provided by the present invention can utilize the MOEMS work. The art production, therefore, makes the displacement sensor and the interferometer provided by the invention have the characteristics of miniaturization and easy integration.
附图说明DRAWINGS
图1为本发明实施例提供的位移传感器的组成结构示意图；1 is a schematic structural diagram of a displacement sensor according to an embodiment of the present invention;
图2为本发明实施例提供的位移传感器的使用方法的流程示意图；2 is a schematic flow chart of a method for using a displacement sensor according to an embodiment of the present invention;
图3为本发明实施例提供的位移传感器工作过程中光线传播的示意图。FIG. 3 is a schematic diagram of light propagation during operation of a displacement sensor according to an embodiment of the present invention.
具体实施方式detailed description
为了更清楚地说明本发明实施例和技术方案，下面将结合附图及实施例对本发明的技术方案进行更详细的说明，显然，所描述的实施例是本发明的一部分实施例，而不是全部实施例。基于本发明的实施例，本领域普通技术人员在不付出创造性劳动的前提下所获得的所有其他实施例，都属于本发明保护的范围。In order to explain the embodiments and technical solutions of the present invention more clearly, the technical solutions of the present invention will be described in more detail below with reference to the accompanying drawings and embodiments. It is obvious that the described embodiments are a part of the embodiments of the present invention, and not all Example. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without departing from the inventive scope are the scope of the present invention.
图1为本发明实施例提供的位移传感器的结构示意图，如图1所示，该位移传感器包括：FIG. 1 is a schematic structural diagram of a displacement sensor according to an embodiment of the present invention. As shown in FIG. 1 , the displacement sensor includes:
半导体激光器101，用于产生激光光束；a semiconductor laser 101 for generating a laser beam;
衍射光栅102，用于将所述激光光束中的一部分光直接衍射再反射，产生第一衍射光；同时用于将所述激光光束中穿过自身、到达待测物体，并经待测物体反射后再次穿过自身的一部分光衍射，形成第二衍射光；a diffraction grating 102 for directly diffracting and reflecting a part of the light of the laser beam to generate a first diffracted light; and simultaneously for passing the laser beam through itself, reaching an object to be measured, and reflecting by the object to be tested After that, a part of the light is again diffracted through itself to form a second diffracted light;
探测器103，位于待测第一衍射光和第二衍射光中预设相同级次的衍射光交汇处，用于测量第一衍射光与第二衍射光中预设相同级次的衍射光之间的干涉强度信息的变化；The detector 103 is located at the intersection of the diffracted lights of the first order of the first diffracted light and the second diffracted light, and is used for measuring the diffracted light of the first order of the first diffracted light and the second diffracted light. Change in interference intensity information;
信息处理器104，与所述探测器相连，用于读取干涉强度信号，根据探测器探测的干涉强度变化信息，反演出待测物体的位移信息；The information processor 104 is connected to the detector for reading the interference intensity signal, and inverting the displacement information of the object to be tested according to the interference intensity change information detected by the detector;
所述衍射光栅位于半导体激光器与待测物体之间。 The diffraction grating is located between the semiconductor laser and the object to be tested.
具体的，上述位移传感器中，所述半导体激光器101可以是长相干距离半导体激光器，使得所述位移传感器可以测量较大的位移，该位移传感器的量程是半导体激光器相干距离的一半，随着长相干距离半导体激光器技术的不断进步，所发明的位移传感器的量程可以达到数米甚至更远。Specifically, in the above displacement sensor, the semiconductor laser 101 may be a long coherence distance semiconductor laser, so that the displacement sensor can measure a large displacement, and the range of the displacement sensor is half of the coherence distance of the semiconductor laser, with long coherence Along with the advancement of semiconductor laser technology, the range of the displacement sensor invented can reach several meters or more.
此外，上述位移传感器中，衍射光栅102可以是对激光半反半透的光栅来实现。Further, in the above displacement sensor, the diffraction grating 102 may be implemented as a grating that is transflective to the laser light.
进一步的，上述位移传感器中，所述探测器103可以是光电探测器；该探测器103的位置是与半导体激光器101发射的激光波长、衍射光栅102的周期，以及要测量发生干涉的衍射光的级次有关的，当衍射光栅的周期和激光波长确定后，衍射光中各衍射级次的方向就确定，探测器的位置由待测衍射级次的方向和探测面与衍射光栅的距离来确定。因而，需预先设定具体测量哪一级衍射光，在实际应用中，可根据具体情况设定为测定0级，±1级，±2级等，即上述预设相同级次的衍射光可以是0级，±1级，±2级等级次的衍射光。Further, in the above displacement sensor, the detector 103 may be a photodetector; the position of the detector 103 is the wavelength of the laser light emitted from the semiconductor laser 101, the period of the diffraction grating 102, and the diffracted light to be measured to interfere. Related to the order, when the period of the diffraction grating and the laser wavelength are determined, the direction of each diffraction order in the diffracted light is determined, and the position of the detector is determined by the direction of the diffraction order to be measured and the distance between the detection surface and the diffraction grating. . Therefore, it is necessary to preset which level of diffracted light is specifically measured. In practical applications, it can be set to 0, ±1, ±2, etc. according to the specific situation, that is, the diffracted light of the same order of the above-mentioned preset can be It is a class 0, ±1 level, ±2 level diffracted light.
此外，上述位移传感器中，信息处理器104在实际应用中，可由位于位移传感器中的中央处理器(CPU)、微处理器(MPU)、数字信号处理器(DSP)、或现场可编程门阵列(FPGA)实现。In addition, in the above displacement sensor, the information processor 104 may be in a practical application by a central processing unit (CPU), a microprocessor (MPU), a digital signal processor (DSP), or a field programmable gate array located in the displacement sensor. (FPGA) implementation.
进一步的，上述位移传感器还可包括：Further, the above displacement sensor may further include:
衍射光栅调制解调装置105，用于对衍射光栅引入周期性的振动，以及对探测器探测到的干涉强度信息进行解调。The diffraction grating modulation and demodulation device 105 is configured to introduce periodic vibration to the diffraction grating and demodulate the interference intensity information detected by the detector.
具体的，衍射光栅调制解调装置105可以通过压电调制等方法实现，衍射光栅调制解调装置的目的在于抑制测量过程中的噪声，它可以借助于微小信号处理中的锁相放大等方法来提高探测信号的信噪比，从而提高位移测量精度。 Specifically, the diffraction grating modulation and demodulation device 105 can be implemented by a method such as piezoelectric modulation. The purpose of the diffraction grating modulation and demodulation device is to suppress noise during measurement, and it can be implemented by means of phase lock amplification in a small signal processing. Improve the signal-to-noise ratio of the detection signal to improve the accuracy of the displacement measurement.
进一步的，上述位移传感器还可包括：Further, the above displacement sensor may further include:
反射光收集装置106，用于收集经待测物体反射的光，使得所探测第二衍射光与第一衍射光中预设相同级次的衍射光的强度相当。The reflected light collecting device 106 is configured to collect the light reflected by the object to be tested, so that the detected second diffracted light has the same intensity as the diffracted light of the first order of the first diffracted light.
具体的，反射光收集装置106可以通过透镜等方法实现，反射光收集装置106的目的在于使更多的待测物体反射的光参与相干，理想的情况是参与相干的两束光的强度等同。Specifically, the reflected light collecting device 106 can be implemented by a lens or the like. The purpose of the reflected light collecting device 106 is to cause more light reflected by the object to be measured to participate in coherence. Ideally, the intensity of the two beams participating in the coherence is equal.
本发明提供的上述位移传感器，若除去信息处理器104，剩下的部分本身是一种干涉仪，因此，本发明还提供一种干涉仪，其包括：The above displacement sensor provided by the present invention, if the information processor 104 is removed, the remaining portion itself is an interferometer. Therefore, the present invention also provides an interferometer comprising:
半导体激光器，用于产生激光光束；a semiconductor laser for generating a laser beam;
衍射光栅，用于将所述激光光束中的一部分光直接衍射再反射，产生第一衍射光；同时用于将所述激光光束中穿过自身、到达待测物体，并经待测物体反射后再次穿过自身的一部分光衍射，形成第二衍射光；a diffraction grating for directly diffracting and reflecting a part of the light of the laser beam to generate a first diffracted light; and simultaneously for passing the laser beam through itself, reaching an object to be measured, and reflecting the object to be tested Diffracting a portion of the light again through itself to form a second diffracted light;
探测器，位于待测第一衍射光和第二衍射光中预设相同级次的衍射光交汇处，用于测量第一衍射光与第二衍射光中预设相同级次的衍射光之间的干涉强度信息的变化。a detector, located at the intersection of the diffracted lights of the first order of the first diffracted light and the second diffracted light, for measuring between the first diffracted light and the second diffracted light The change in the interference intensity information.
进一步的，上述干涉仪还包括：Further, the interferometer further includes:
衍射光栅调制解调装置，用于对衍射光栅引入周期性的振动，以及对探测器探测到的干涉强度信息进行解调。A diffraction grating modulation and demodulation device for introducing periodic vibration to the diffraction grating and demodulating the interference intensity information detected by the detector.
进一步的，上述干涉仪还包括：Further, the interferometer further includes:
反射光收集装置，用于收集经待测物体反射的光，使得所探测第二衍射光与第一衍射光中预设相同级次的衍射光的强度相当。The reflected light collecting device is configured to collect the light reflected by the object to be measured, so that the detected second diffracted light has the same intensity as the diffracted light of the first order of the first diffracted light.
进一步的，上述干涉仪中，所述半导体激光器为长相干距离半导体激光器。 Further, in the above interferometer, the semiconductor laser is a long coherence distance semiconductor laser.
图2为本发明提供的上述位移传感器的使用方法的流程示意图，如图2所示，该方法包括：2 is a schematic flow chart of a method for using the above displacement sensor according to the present invention. As shown in FIG. 2, the method includes:
步骤201，半导体激光器产生激光光束； Step 201, the semiconductor laser generates a laser beam;
步骤202，衍射光栅将所述激光光束中的一部分光直接衍射再反射，产生第一衍射光；同时衍射光栅将所述激光光束中穿过自身、到达待测物体，并经待测物体反射后再次穿过自身的一部分光衍射，形成第二衍射光；Step 202: The diffraction grating directly diffracts and reflects a part of the light of the laser beam to generate a first diffracted light; and the diffraction grating passes the laser beam through itself, reaches an object to be tested, and is reflected by the object to be tested. Diffracting a portion of the light again through itself to form a second diffracted light;
具体的，如图3所示，半导体激光器发出的激光光束入射到衍射光栅表面时，一部分激光光束直接被衍射光栅衍射再反射产生第一衍射光，第一衍射光中包含一系列衍射级次，如0级，±1级，±2级等；同时一部分激光光束穿过衍射光栅到达待测物体，被待测物体反射后经反射光收集装置后再次穿过衍射光栅衍射为第二衍射光，第二衍射光中也包含一系列衍射级次，如0级，±1级，±2级等。Specifically, as shown in FIG. 3, when a laser beam emitted by the semiconductor laser is incident on the surface of the diffraction grating, a part of the laser beam is directly diffracted by the diffraction grating to reflect the first diffracted light, and the first diffracted light includes a series of diffraction orders. Such as 0 level, ±1 level, ±2 level, etc.; at the same time, a part of the laser beam passes through the diffraction grating to reach the object to be measured, is reflected by the object to be measured, and then diffracted into the second diffracted light through the diffraction grating through the reflected light collecting device. The second diffracted light also contains a series of diffraction orders, such as 0, ±1, ±2, and the like.
步骤203，探测器测量第一衍射光与第二衍射光中预设相同级次的衍射光之间的干涉强度信息的变化；Step 203: The detector measures a change in interference intensity information between the first diffracted light and the diffracted light of the second order of the second diffracted light.
具体的，调节衍射光栅使待测物体的反射面与光栅的反射面平行，如图3所示，这时第一衍射光与第二衍射光中预设的相同衍射级次的衍射光的空间方向一致，它们将发生干涉。调节探测器使探测器位于第一衍射光和第二衍射光中预设的相同衍射级次交汇处，如图3所示。这样，探测器就能测量到第一衍射光与第二衍射光干涉强度的变化信息。Specifically, the diffraction grating is adjusted such that the reflection surface of the object to be measured is parallel to the reflection surface of the grating, as shown in FIG. 3, and the space of the diffracted light of the same diffraction order preset in the first diffracted light and the second diffracted light at this time The directions are the same and they will interfere. The detector is adjusted such that the detector is located at the intersection of the same diffraction orders preset in the first diffracted light and the second diffracted light, as shown in FIG. In this way, the detector can measure the change information of the interference intensity between the first diffracted light and the second diffracted light.
这里，所述的预设的相同衍射级次，是指预设第一衍射光与第二衍射光的级次同为0级，同为±1级，同为±2级等。Here, the predetermined same diffraction order means that the order of the first diffracted light and the second diffracted light is 0, the same as ±1, and the same as ±2.
进一步的，可以通过衍射光栅调制解调装置对衍射光栅引入周期性的振动，并对探测器探测到的干涉强度变化信息进行解调，抑制测量过程中的噪声。 Further, the diffraction grating can be introduced into the diffraction grating by the diffraction grating modulation and demodulation device, and the interference intensity change information detected by the detector can be demodulated to suppress noise during the measurement process.
步骤204，信息处理器读取干涉强度信号，根据探测器探测的干涉强度变化信息，反演出待测物体的位移信息；Step 204: The information processor reads the interference intensity signal, and inverts the displacement information of the object to be tested according to the interference intensity change information detected by the detector;
具体的，如图3所示，此时发生干涉的第一衍射光与第二衍射光的光程差是由衍射光栅反射面与待测物体反射面之间的距离决定的，这样和传统的迈克尔逊干涉仪测量位移信息的方法一样，信息处理器根据所述干涉强度变化信息，经过已有的处理电路和执行已有的处理算法后就可以反演出运动物体的位移信息。Specifically, as shown in FIG. 3, the optical path difference between the first diffracted light and the second diffracted light that interferes at this time is determined by the distance between the reflective surface of the diffraction grating and the reflective surface of the object to be measured, and thus The method of measuring the displacement information by the Michelson interferometer is the same. According to the interference intensity change information, the information processor can reverse the displacement information of the moving object after passing through the existing processing circuit and executing the existing processing algorithm.
本发明还提供上述位移传感器的制作方法，该方法包括：The invention also provides a method for manufacturing the above displacement sensor, the method comprising:
使用微光机电系统MOEMS工艺生产半导体激光器、衍射光栅、探测器、信息处理器，以及光栅调制装置、反射光收集装置的MOEMS元件；Production of semiconductor lasers, diffraction gratings, detectors, information processors, and MOEMS components of grating modulation devices and reflected light collection devices using a micro-optical electromechanical system MOEMS process;
将分离的半导体激光器、衍射光栅、光电探测器、信息处理器，以及光栅调制装置、反射光收集装置的MOEMS元件按照根据上述任意一种位移传感器结构组装；或者Separating the semiconductor laser, the diffraction grating, the photodetector, the information processor, and the MOEMS element of the grating modulation device and the reflected light collecting device according to any one of the above displacement sensor structures; or
将半导体激光器、衍射光栅、光电探测器、信息处理器，以及光栅调制装置、反射光收集装置的MOEMS元件中的全部或部分元件集成于一个单片中。All or part of the semiconductor laser, the diffraction grating, the photodetector, the information processor, and the grating modulation device, the MOEMS element of the reflected light collecting device are integrated into one single piece.
具体的，将分离的半导体激光器、衍射光栅、光栅调制装置、反射光收集装置、光电探测器、信息处理器等参考图1组装起来，构成所发明的位移传感器；或者Specifically, a separate semiconductor laser, a diffraction grating, a grating modulation device, a reflected light collecting device, a photodetector, an information processor, and the like are assembled with reference to FIG. 1 to constitute the inventive displacement sensor; or
利用现有的MOEMS工艺将半导体激光器、衍射光栅、光电探测器、信息处理器，以及光栅调制装置、反射光收集装置的MOEMS元件中的全部或部分元件集成于一个单片中，制作出全集成或半集成的MOEMS位移传感器。Using the existing MOEMS process to integrate all or part of the semiconductor laser, diffraction grating, photodetector, information processor, and grating modulation device, MOEMS component of the reflected light collecting device into a single chip, to make a fully integrated Or semi-integrated MOEMS displacement sensor.
上述的技术方案的特点是：本发明提供的位移传感器的探测光可以是由长相干距离半导体激光器提供，并不像现有的双光束位移测量系统，探测光由He-Ne激光器等提供。这样所发明的位移传感器具有微型化、易集成等特点。 传感器所测量的最大量程是半导体激光器相干距离的一半，随着长相干距离半导体激光器技术的不断进步，所发明的位移传感器的量程可以达到数米甚至更远。The above technical solution is characterized in that the probe light of the displacement sensor provided by the present invention can be provided by a long coherence distance semiconductor laser, unlike the existing dual beam displacement measurement system, and the probe light is provided by a He-Ne laser or the like. The displacement sensor thus invented has the characteristics of miniaturization and easy integration. The maximum range measured by the sensor is half the coherence distance of the semiconductor laser. With the continuous advancement of the long coherence distance semiconductor laser technology, the range of the invented displacement sensor can reach several meters or more.
上述技术方案的另外一个特点是：产生相干双光束的方法并不是像迈克尔逊干涉仪那样利用不同的光路来实现，而是利用衍射光栅的半反半透性质来实现分光的。光栅的直接反射和待测物体的表面反射提供了两束相干光，它们的光程差包含了待测物体的位移信息。相互干涉的两束光可以是第一衍射光与第二衍射光中任何一级的衍射光，如0级，±1级，±2级等，它们的空间方向不同，因此利用不同级别衍射光相干信息测量时，相应探测器的空间位置也不同。Another feature of the above technical solution is that the method of generating the coherent double beam is not realized by using different optical paths like the Michelson interferometer, but by using the semi-transverse property of the diffraction grating to achieve the splitting. The direct reflection of the grating and the surface reflection of the object to be measured provide two coherent lights whose optical path difference contains the displacement information of the object to be measured. The two beams that interfere with each other may be diffracted light of any one of the first diffracted light and the second diffracted light, such as 0th order, ±1 order, ±2 order, etc., and their spatial directions are different, so different levels of diffracted light are utilized. When the coherent information is measured, the spatial position of the corresponding detector is also different.
上述的技术方案的另外一个特点是：可以对衍射光栅引入调制系统。对衍射光栅引入周期性的振动，而后对探测器探测到的干涉强度信息进行解调；这样可以有效地抑制和降低噪声，提高测量精度。Another feature of the above technical solution is that a modulation system can be introduced to the diffraction grating. Periodic vibration is introduced into the diffraction grating, and then the interference intensity information detected by the detector is demodulated; this can effectively suppress and reduce noise and improve measurement accuracy.
在制造方式上，可以通过分离的元件贴片搭建而成，也可以是集成的。通过分离的元件贴片搭建时，将分离的半导体激光器、衍射光栅、光栅调制装置、反射光收集装置、光电探测器、信息处理器等参考图1组装起来，构成所发明的位移传感器。由于所发明的位移传感器中各个元件的制作都与现有的MOEMS工艺兼容，因此也可以利用所有的MOEMS工艺制作出单片集成的位移传感器。In terms of manufacturing method, it can be built by separate component patches or integrated. When the separated component patches are constructed, separate semiconductor lasers, diffraction gratings, grating modulation devices, reflected light collecting devices, photodetectors, information processors, and the like are assembled with reference to FIG. 1 to constitute the inventive displacement sensor. Since the components of the invented displacement sensor are manufactured to be compatible with existing MOEMS processes, a single integrated displacement sensor can be fabricated using all MOEMS processes.
以上所述，仅为本发明的较佳实施例而已，并非用于限定本发明的保护范围。 The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Claims (10)

  1. 一种位移传感器，其特征在于，所述位移传感器包括：A displacement sensor, characterized in that the displacement sensor comprises:
    半导体激光器，用于产生激光光束；a semiconductor laser for generating a laser beam;
    衍射光栅，用于将所述激光光束中的一部分光直接衍射再反射，产生第一衍射光；同时用于将所述激光光束中穿过自身、到达待测物体，并经待测物体反射后再次穿过自身的一部分光衍射，形成第二衍射光；a diffraction grating for directly diffracting and reflecting a part of the light of the laser beam to generate a first diffracted light; and simultaneously for passing the laser beam through itself, reaching an object to be measured, and reflecting the object to be tested Diffracting a portion of the light again through itself to form a second diffracted light;
    探测器，位于待测第一衍射光和第二衍射光中预设相同级次的衍射光交汇处，用于测量第一衍射光与第二衍射光中预设相同级次的衍射光之间的干涉强度变化信息；a detector, located at the intersection of the diffracted lights of the first order of the first diffracted light and the second diffracted light, for measuring between the first diffracted light and the second diffracted light Interference intensity change information;
    信息处理器，与所述探测器相连，用于读取干涉强度信号，根据探测器探测的干涉强度信息的变化，反演出待测物体的位移信息；An information processor is connected to the detector for reading the interference intensity signal, and inverting the displacement information of the object to be tested according to the change of the interference intensity information detected by the detector;
    所述衍射光栅位于半导体激光器与待测物体之间。The diffraction grating is located between the semiconductor laser and the object to be tested.
  2. 根据权利要求1所述的位移传感器，其特征在于，所述位移传感器还包括：The displacement sensor of claim 1 wherein the displacement sensor further comprises:
    衍射光栅调制解调装置，用于对衍射光栅引入周期性的振动，以及对探测器探测到的干涉强度信息进行解调。A diffraction grating modulation and demodulation device for introducing periodic vibration to the diffraction grating and demodulating the interference intensity information detected by the detector.
  3. 根据权利要求1或2所述的位移传感器，其特征在于，所述位移传感器还包括：The displacement sensor according to claim 1 or 2, wherein the displacement sensor further comprises:
    反射光收集装置，用于收集经待测物体反射的光，使得所探测第二衍射光与第一衍射光中预设相同级次的衍射光的强度相当。The reflected light collecting device is configured to collect the light reflected by the object to be measured, so that the detected second diffracted light has the same intensity as the diffracted light of the first order of the first diffracted light.
  4. 根据权利要求1至3任一项所述的位移传感器，其特征在于，所述半导体激光器为长相干距离半导体激光器。 The displacement sensor according to any one of claims 1 to 3, wherein the semiconductor laser is a long coherence distance semiconductor laser.
  5. 一种干涉仪，其特征在于，所述干涉仪包括：An interferometer, characterized in that the interferometer comprises:
    半导体激光器，用于产生激光光束；a semiconductor laser for generating a laser beam;
    衍射光栅，用于将所述激光光束中的一部分光直接衍射再反射，产生第一衍射光；同时用于将所述激光光束中穿过自身、到达待测物体，并经待测物体反射后再次穿过自身的一部分光衍射，形成第二衍射光；a diffraction grating for directly diffracting and reflecting a part of the light of the laser beam to generate a first diffracted light; and simultaneously for passing the laser beam through itself, reaching an object to be measured, and reflecting the object to be tested Diffracting a portion of the light again through itself to form a second diffracted light;
    探测器，位于待测第一衍射光和第二衍射光中预设相同级次的衍射光交汇处，用于测量第一衍射光与第二衍射光中预设相同级次的衍射光之间的干涉强度信息的变化。a detector, located at the intersection of the diffracted lights of the first order of the first diffracted light and the second diffracted light, for measuring between the first diffracted light and the second diffracted light The change in the interference intensity information.
  6. 根据权利要求5所述的干涉仪，其特征在于，所述干涉仪还包括：The interferometer of claim 5, wherein the interferometer further comprises:
    衍射光栅调制解调装置，用于对衍射光栅引入周期性的振动，以及对探测器探测到的干涉强度信息进行解调。A diffraction grating modulation and demodulation device for introducing periodic vibration to the diffraction grating and demodulating the interference intensity information detected by the detector.
  7. 根据权利要求5所述的干涉仪，其特征在于，所述干涉仪还包括：The interferometer of claim 5, wherein the interferometer further comprises:
    反射光收集装置，用于收集经待测物体反射的光，使得所探测第二衍射光与第一衍射光中预设相同级次的衍射光的强度相当。The reflected light collecting device is configured to collect the light reflected by the object to be measured, so that the detected second diffracted light has the same intensity as the diffracted light of the first order of the first diffracted light.
  8. 根据权利要求5至7任一项所述的干涉仪，其特征在于，所述半导体激光器为长相干距离半导体激光器。The interferometer according to any one of claims 5 to 7, wherein the semiconductor laser is a long coherence distance semiconductor laser.
  9. 一种位移传感器的使用方法，其特征在于，该方法包括：A method of using a displacement sensor, the method comprising:
    半导体激光器产生激光光束；a semiconductor laser generates a laser beam;
    衍射光栅将所述激光光束中的一部分光直接衍射再反射，产生第一衍射光；同时衍射光栅将所述激光光束中穿过自身、到达待测物体，并经待测物体反射后再次穿过自身的一部分光，衍射为第二衍射光；The diffraction grating directly diffracts and reflects a part of the light of the laser beam to generate a first diffracted light; at the same time, the diffraction grating passes the laser beam through itself, reaches an object to be measured, and passes through the object to be measured to pass through again. a part of the light of itself, diffracted into the second diffracted light;
    探测器测量第一衍射光与第二衍射光中预设相同级次的衍射光之间的干涉强度信息的变化； The detector measures a change in interference intensity information between the first diffracted light and the diffracted light of the second order of the second diffracted light;
    信息处理器读取干涉强度信号，根据探测器探测的干涉强度变化信息，反演出待测物体的位移信息。The information processor reads the interference intensity signal and inverts the displacement information of the object to be tested according to the interference intensity change information detected by the detector.
  10. 一种位移传感器的制作方法，其特征在于，该方法包括：A method for manufacturing a displacement sensor, the method comprising:
    使用微光机电系统MOEMS工艺生产半导体激光器、衍射光栅、探测器、信息处理器，以及光栅调制装置、反射光收集装置的MOEMS元件；Production of semiconductor lasers, diffraction gratings, detectors, information processors, and MOEMS components of grating modulation devices and reflected light collection devices using a micro-optical electromechanical system MOEMS process;
    将分离的半导体激光器、衍射光栅、光电探测器、信息处理器，以及光栅调制装置、反射光收集装置的MOEMS元件按照根据权利要求1至4任一项所述的位移传感器结构组装；或者Separating the semiconductor laser, the diffraction grating, the photodetector, the information processor, and the MOEMS element of the grating modulation device, the reflected light collecting device, according to the displacement sensor structure according to any one of claims 1 to 4; or
    将半导体激光器、衍射光栅、光电探测器、信息处理器，以及光栅调制装置、反射光收集装置的MOEMS元件中的全部或部分元件集成于一个单片中。 All or part of the semiconductor laser, the diffraction grating, the photodetector, the information processor, and the grating modulation device, the MOEMS element of the reflected light collecting device are integrated into one single piece.
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