Electrostriction coefficient measuring device based on loyd's mirror interferometry

Abstract

The utility model belongs to the technical field of material characteristic parameter measurement, and relates to an electrostriction coefficient measuring device based on a loyd mirror interference method, which comprises a light source used for emitting laser and enabling the laser to be incident to a reflecting mirror at a grazing incidence angle; the power supply is used for applying voltage to the to-be-tested sample to change the deformation quantity of the to-be-tested sample; the supporting block and the to-be-detected sample are positioned on the same horizontal plane; the reflector is placed on the surfaces of the to-be-tested sample and the supporting block, one end is in contact with the to-be-tested sample, and the other end is in contact with the supporting block; the laser reflector is used for reflecting the laser, outputting a first reflected light beam before the deformation quantity of the to-be-detected sample is changed, and outputting a second reflected light beam after the deformation quantity is changed; the optical screen is used for generating first interference fringes and second interference fringes based on interference light of the first reflection light beam, the second reflection light beam and the laser; the image processing module is used for amplifying the first interference fringes and the second interference fringes; and the upper computer is used for obtaining an electrostriction coefficient based on the first interference fringes and the second interference fringes.

Description

Technical Field

[0001] This utility model relates to the field of material property parameter measurement technology, and in particular to an electrostriction coefficient measuring device based on Loewe mirror interferometry. Background Technology

[0002] Electrostriction coefficient is a physical quantity used to describe the degree of strain produced by a material under the influence of an electric field. When a material is placed in an electric field, the charged particles inside it will be displaced under the influence of the electric field force, causing changes in the material's crystal structure, thereby causing changes in the material's shape and size. The electrostriction coefficient can quantitatively represent the relationship between electric field strength and material strain. By measuring the electrostriction coefficient of a material, we can accurately understand the sensitivity of the material to deformation induced by an electric field, thus providing a basis for the selection and application of materials in different application scenarios. For example, in the manufacture of high-precision sensors, it is necessary to find materials with stable and moderate electrostriction coefficients. If the electrostriction coefficient of the material is too large, it will cause the sensor to be overly sensitive to weak electric field signals, generating noise interference. If the electrostriction coefficient is too small, it will not be able to effectively sense changes in the electric field, affecting the sensor's sensitivity.

[0003] Existing devices for measuring the electrostriction coefficient include those based on capacitance, those based on periodic pressure, and those based on vertical loading. For example... Figure 1 The diagram shows a schematic of an electrostriction coefficient measurement device based on the capacitance method. It converts the electrostriction coefficient and strain of the sample into a change in microcapacitance, and measures the electrostriction coefficient by measuring this change in microcapacitance. Combined with the driving force of the drive coil, it measures the electrostriction coefficient and driving force of the material under load. Specifically, it includes an adjustable high-voltage source, a fixed base, a three-dimensional micro-displacement stage, high-voltage positive and negative plates, the sample to be tested, an excitation coil, a micro-displacement sensing capacitor, and its measurement and control circuit. During measurement, the high-voltage power supply applies a strong electric field to the sample, causing deformation. The micro-displacement sensing capacitor measures the corresponding micro-displacement. Simultaneously, a force load is generated by driving the excitation coil to counteract the strong electric field. The entire testing device is placed on an anti-vibration platform to eliminate the influence of vibration on the test results. The electrostriction coefficient of the sample is measured. The specific calculation formula is as follows: ,in, The dielectric constant is The area of ​​the electrode plate is... , These represent the capacitance values ​​of the sample before and after deformation, respectively. While this device can measure the electrostriction coefficient of a sample, it suffers from high output impedance, and the parasitic capacitance between components reduces the device's sensitivity to sample deformation, affecting the accuracy of the measurement results. Figure 2The diagram shows a measurement device based on the periodic pressure method. A piezoelectric transducer with a metal rod attached is placed in close contact with the surface of the sample to be tested. The piezoelectric transducer is connected to a silicon substrate. The piezoelectric transducer converts the step pulse generated by the pulse generator into a longitudinal audio pulse, which is then propagated to the coupling liquid through the metal rod. The audio pulse generates a mechanical load on the sample to be tested. Simultaneously, the mechanical deformation of the sample to be tested is converted into an electrical signal and output from the electrodes. Assuming the collected charge is... The sample to be tested was replaced with a reference piezoelectric element with a known electrostriction coefficient, and the above operation was repeated. The collected charge was... The electrostriction coefficient of the sample to be tested is... , The electrostriction coefficient of the reference piezoelectric element is used as a reference. When measuring the electrostriction coefficient of a sample using this device, the sample and the reference piezoelectric element need to undergo identical measurement operations to ensure accuracy. However, the sample and the reference piezoelectric element have different wettability to the coupling liquid, making this requirement difficult to meet. Furthermore, resonance occurs when the pulse frequency generated by the pulse generator is lower than the frequency of free electrons in the sample film or higher than the fundamental mode frequency, affecting the measurement results. In addition, the bending effect of the substrate during the measurement process also affects the accuracy of the results. The measurement device based on the vertical loading method applies a mechanical load F to the upper and lower surfaces of the sample to generate a certain charge Q on the electrodes. A standard capacitor with a capacitance much larger than that of the sample is connected in series with the sample. The voltage across the standard capacitor is measured using an electrometer to calculate the electrostriction coefficient of the sample. The specific calculation formula is as follows: ,in, This is the capacitance value of a standard capacitor. The voltage across the standard capacitor is used to measure the mechanical load applied to the sample through one or more specific points. This results in uneven stress on the sample, causing it to tilt or deform locally, which in turn affects the accuracy of the measurement results.

[0004] To address the problems with the aforementioned measuring devices, a new electrostriction coefficient measuring device based on the Michelson interferometry has been proposed in the prior art, such as... Figure 3As shown, M1 and M2 are plane mirrors, and G is a semi-transparent, semi-reflective beam splitter used to split the light projected from the light source into two beams of equal intensity, which are then projected onto M1 and M2 respectively. M1 and M2 reflect the beams to G1, where they interfere after reflection or transmission, producing interference fringes on the receiving screen. By applying DC voltages to both ends of the sample under test along its polarization direction (direction 2) and perpendicular to its polarization direction (direction 1), deformation is generated in directions 1 and 2. The interference fringes generated on the receiving screen before and after the deformation of the sample are obtained using a microscope. The electrostriction coefficient of the sample is then calculated using a host computer based on the number of fringe shifts in the interference fringes before and after deformation. The specific calculation formula is as follows: ,in, The dimension of the sample to be tested perpendicular to the polarization direction. The dimension of the sample under test is the polarization direction. The magnitude of the DC voltage applied across the polarization direction of the sample under test. The deformation of the sample under test in the direction perpendicular to polarization. To determine the number of fringe shifts in the interference fringes generated before and after deformation of the sample, this device directly applies a voltage to the sample and uses optical principles to obtain the interference fringes before and after deformation. By comparing the changes in the interference fringes, the device reflects the deformation of the sample under different voltages, thus accurately obtaining the electrostriction coefficient of the sample. However, this device requires a large number of optical components, has a complex structure, and is costly. Summary of the Invention

[0005] Therefore, the technical problem to be solved by this utility model is to overcome the problems of existing electrostriction coefficient measuring devices having a large number of optical elements, complex structure and high cost.

[0006] To solve the above-mentioned technical problems, this utility model provides an electrostriction coefficient measuring device based on the Loewe mirror interferometry, comprising:

[0007] A light source for emitting laser light, such that the laser light is incident on the reflector at a grazing angle of incidence;

[0008] A power supply, connected to the sample under test, is used to apply voltage to the sample under test, thereby changing the deformation of the sample under test;

[0009] The support block is located on the same horizontal plane as the sample to be tested;

[0010] A reflector is placed on the surface of the sample to be tested and the support block, with one end in contact with the sample to be tested and the other end in contact with the support block; it is used to reflect the laser and output a first reflected beam before the deformation of the sample to be tested changes, and output a second reflected beam after the deformation of the sample to be tested changes.

[0011] A light screen is used to generate a first interference fringe based on the interference light of the first reflected beam and the laser, and to generate a second interference fringe based on the interference light of the second reflected beam and the laser.

[0012] An image processing module, connected to a host computer, is used to acquire and amplify the first interference fringe and the second interference fringe, and send the first interference fringe and the second interference fringe to the host computer.

[0013] The host computer is used to obtain the electrostriction coefficient of the sample under test based on the first interference fringe and the second interference fringe.

[0014] Preferably, the host computer is connected to the power supply and is used to send control signals to the power supply to control the voltage of the power supply to change, thereby changing the deformation of the sample to be tested.

[0015] Preferably, it further includes:

[0016] A support platform for placing the sample to be tested and the support block;

[0017] Multiple iron frames are used to fix the light source, the light screen and the image processing module, respectively.

[0018] Preferably, both the support platform and the support block are 3D printed parts.

[0019] Preferably, the height of the support block is equal to the height of the sample under test when the deformation is 0, so that the reflector can be placed horizontally on the surface of the sample under test and the support block.

[0020] Preferably, the size of the contact area between the reflector and the sample under test is smaller than the size of the surface of the sample under test that contacts the reflector.

[0021] Preferably, when the sample to be tested is a piezoelectric ceramic tube,

[0022] The positive terminal of the power supply is connected to the inner wall of the piezoelectric ceramic tube, and the negative terminal of the power supply is connected to the outer wall of the piezoelectric ceramic tube.

[0023] The size of the contact area between the reflector and the piezoelectric ceramic tube is smaller than the wall thickness of the piezoelectric ceramic tube.

[0024] Preferably, the piezoelectric ceramic tube has an outer diameter of 24 mm, an inner diameter of 20 mm, and a height of 23 mm.

[0025] The reflector is 50mm long and 40mm wide;

[0026] The diameter of the contact area between the reflector and the sample under test is less than 2 mm.

[0027] Preferably, the image processing module is a digital microscope, a CCD camera, or a high-speed camera.

[0028] Preferably, the power supply is a DC regulated power supply.

[0029] This invention provides an electrostriction measurement device based on the Loewe mirror interferometry method. A laser beam is emitted from a light source and incident on a reflecting mirror at a grazing angle. The mirror reflects the laser beam, and because the reflected beam from the mirror overlaps and interferes with the laser emitted from the light source, interference fringes are generated on a screen. Based on the Loewe mirror interferometry principle, this application only requires one reflecting mirror to generate interference fringes, eliminating the need for a beam splitter and multiple reflecting mirrors, thus reducing the number of optical components. A voltage is applied to the sample under test to change its deformation. By placing the reflecting mirror on the surface of the sample and the support block, the deformation of the sample under voltage causes the reflecting mirror to be raised or lowered. By changing the reflection angle of the reflector to the light source, different reflected beams are output, altering the overlap range between the reflected beams and the laser. This causes the screen to generate different interference fringes based on the interference phenomena of different reflected beams and the laser, thereby obtaining the interference fringes corresponding to the deformation changes of the sample under test. The interference fringes are then magnified using an image processing module, and finally, the electrostriction coefficient of the sample under test can be obtained by the host computer based on the interference fringes before and after the deformation changes. The interference fringes corresponding to different deformations of the sample under test can be obtained using only one reflector. The structure is simple, easy to disassemble and assemble, convenient to carry and operate, and inexpensive. It can be applied to samples of various sizes and has wide applicability. Attached Figure Description

[0030] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein:

[0031] Figure 1 A schematic diagram of the electrostriction coefficient measuring device based on the capacitance method provided in this application;

[0032] Figure 2 A schematic diagram of the electrostriction coefficient measuring device based on the periodic pressure method provided in this application;

[0033] Figure 3 A schematic diagram of the electrostriction coefficient measuring device based on Michelson interferometry provided in this application;

[0034] Figure 4 This application provides a schematic diagram of the Loehr mirror interference principle.

[0035] Figure 5 This application provides a schematic diagram of the structure of a sample to be tested.

[0036] Figure 6 A schematic diagram showing the axial height increment of the sample under test provided in this application under voltage.

[0037] Figure 7 A schematic diagram showing the relationship between the deformation of the sample to be tested and the resulting interference fringes provided in this application;

[0038] Figure 8 A schematic diagram of the electrostriction coefficient measuring device based on the Loehn mirror interferometry provided in this application;

[0039] Figure 9 A physical image of the electrostriction measuring device based on the Loeux mirror interferometry provided for this application;

[0040] Explanation of the reference numerals in the instruction manual: 1. Light source; 2. Power supply; 3. Sample to be tested; 4. Support block; 5. Reflector; 6. Screen; 7. Image processing module; 8. Host computer; 9. Support platform; 10. Iron frame. Detailed Implementation

[0041] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.

[0042] This application designs an electrostriction coefficient measuring device based on the Loewe mirror interferometry principle and the inverse piezoelectric effect principle, such as... Figure 4 The diagram shows the principle of Loewe mirror interference. In the diagram, M is a horizontally placed mirror, S1 is a slit, S2 is the virtual image of S1 formed by the mirror M, P is the observation screen, a represents the distance between the light source and M, l represents the length of M, D represents the perpendicular distance between S1 and P, and A represents the distance between S1 and P.

[0043] When the incident light enters the mirror at a grazing angle of incidence from S1, the reflected light (equivalent to the beam emitted from S2) and the beam emitted directly from S1 come from the same wavefront, thus exhibiting the characteristics of coherent light. At the same time, since the range of the reflected beam output by the mirror overlaps with the beam emitted directly from S1, the two beams interfere in the overlapping area, forming interference fringes. Specifically, the interference fringes are approximately parallel straight fringes with equal spacing.

[0044] When the height of the reflector M changes, its reflection angle changes accordingly, and the overlap area between the output reflected beam and the beam emitted directly from S1 changes, thus changing the interference fringes formed. Based on this principle, this application places the reflector M on the surface of the sample to be tested. When the sample to be tested deforms under the action of voltage, the height of the reflector M changes accordingly, and the overlap area between the output reflected beam and the light source changes, thereby generating different interference fringes on the screen. By measuring the displacement of the interference fringes, the deformation of the sample to be tested can be accurately calculated, thereby obtaining its electrostriction coefficient.

[0045] When the sample to be tested is Figure 5 The tubular structure shown, with a height of L and a wall thickness of d, is tested by applying voltages to the inner and outer walls of the sample. This allows the sample to deform under the influence of an electric field E, which is expressed as:

[0046] ,

[0047] Under the piezoelectric effect, the deformation of the sample under test The linear relationship between the electric field and the electric field is:

[0048] ,

[0049] in, This is the electrostriction coefficient of the sample under test. The axial deformation of the sample under test under voltage;

[0050] Then the electrostriction coefficient of the sample to be tested It can be represented as:

[0051] ,

[0052] Due to the axial deformation of the sample under voltage Since these are minute quantities, they are difficult to measure accurately; therefore, it is necessary to construct different deformation methods. With interference fringe displacement The relationship between these factors is used to obtain the electrostriction coefficient of the sample under test.

[0053] Furthermore, such as Figure 6 As shown, the axial deformation of the sample under test under voltage. and It conforms to the principle of triangle similarity:

[0054] ,

[0055] From the above formula, we can obtain and Satisfying the relation:

[0056] ,

[0057] Furthermore, such as Figure 7 As shown, according to the principle of similar triangles, we can obtain:

[0058] ,

[0059] in, The coordinates of the interference fringes;

[0060] Transforming the above formula yields:

[0061] ,

[0062] ,

[0063] Furthermore, it can be seen that, and Satisfying the relation:

[0064] ,

[0065] Substituting this relationship into the electrostriction coefficient of the sample to be tested... The calculation formula can be obtained as follows:

[0066] ,

[0067] like If there is a linear relationship between U and U, then its linear correlation coefficient satisfies:

[0068] ,

[0069] Furthermore, the electrostriction coefficient of the sample under test can be expressed as:

[0070] .

[0071] Based on the above principles, this application provides an electrostriction coefficient measuring device based on the Loewe mirror interferometry method. Please refer to the following: Figure 8 and Figure 9 , Figure 8 The figure shown is a schematic diagram of the electrostriction measurement device based on the Loehn mirror interferometry provided in this application. Figure 9 This is a physical image of the device. The device specifically includes a light source 1, a power supply 2, a sample to be tested 3, a support block 4, a reflector 5, a light screen 6, an image processing module 7, and a host computer 8.

[0072] Light source 1 is a laser source used to emit laser light, so that the laser light is incident on the reflector 5 at a grazing incidence angle.

[0073] Power supply 2 is connected to the sample 3 under test and is used to apply voltage to the sample 3 under test, thereby changing the deformation of the sample 3 under test. Specifically, power supply 2 is a DC regulated power supply.

[0074] Support block 4 and sample 3 to be tested are located on the same horizontal plane.

[0075] The reflector 5 is placed on the support block 4 and the surface of the sample 3 to be tested, with one end in contact with the support block 4 and the other end in contact with the sample 3 to be tested. It is used to reflect the laser emitted by the light source 1, outputting a first reflected beam before the deformation of the sample 3 to be tested changes, and outputting a second reflected beam after the deformation of the sample 3 to be tested changes.

[0076] Specifically, by adjusting the height of the reflector 5 and the light source 1, the reflected beam output by the reflector 5 after reflecting the laser can overlap with the laser beam, thus producing interference and generating interference fringes on the screen 6. For example, before measurement, the positions and angles of the light source 1, reflector 5, and screen 6 are adjusted so that the light source 1 is nearly parallel to the reflector 5, until alternating bright and dark interference fringes appear on the screen 6, indicating that the reflected beam output by the reflector 5 interferes with the laser emitted by the light source 1.

[0077] Specifically, the sample 3 under test will elongate or shorten under the action of voltage, thereby raising or lowering the height of the side of the reflector 5 in contact with the sample 3. This changes the reflection angle of the reflector 5 for the laser, causing a change in the overlap range between the reflected beam and the laser, and consequently changing the interference fringes generated by the screen 6. Therefore, when the reflector 5 reflects the laser based on the reflection angle before the deformation of the sample 3 changes, it outputs a first reflected beam; when it reflects the laser based on the reflection angle after the deformation of the sample 3 changes, it outputs a second reflected beam.

[0078] The light screen 6 generates a first interference fringe based on the overlapping area of ​​the first reflected beam output from the reflector 5 and the laser emitted by the light source 1, and generates a second interference fringe based on the overlapping area of ​​the second reflected beam output from the reflector 5 and the laser emitted by the light source 1.

[0079] The image processing module 7 is connected to the host computer 8 and is used to amplify the first interference fringe and the second interference fringe, and send the first interference fringe and the second interference fringe to the host computer 8.

[0080] Optionally, the image processing module 7 can be a device such as a digital microscope, CCD camera, or high-speed camera that can capture and magnify the interference fringes generated by the screen 6.

[0081] The host computer 8 is used to obtain the electrostriction coefficient of the sample 3 under test based on the first interference fringe and the second interference fringe.

[0082] Specifically, after receiving the first and second interference fringes, the host computer 8 can calculate the electrostriction coefficient of the sample 3 under test using existing electrostriction coefficient calculation formulas. For example, the formula for measuring the electrostriction coefficient using the Michelson interferometry method can be used. , This represents the electrostriction coefficient of sample 3. This indicates the number of times the second interference fringe has shifted relative to the first interference fringe when observed at a fixed point. Indicates wavelength. This indicates the voltage level of power supply 2. This represents the length of sample 3 perpendicular to the polarization direction. This indicates the length of the polarization direction of the sample under test.

[0083] Furthermore, in some embodiments of this application, the host computer 8 is also connected to the power supply 2, and the host computer 8 is also used to send control signals to the power supply 2 to control the voltage of the power supply 2 to change, thereby changing the deformation of the sample 3 to be tested.

[0084] When the deformation of the sample 3 under test changes, the reflection angle of the laser by the reflector 5 also changes. Therefore, the reflector 5 reflects the laser based on the reflection angle corresponding to different deformations of the sample 3 under test, thereby outputting the reflected beam corresponding to different deformations. The screen 6 generates multiple interference fringes based on the interference of the reflected beams corresponding to different deformations and the laser. The image processing module 7 amplifies the multiple interference fringes and sends them to the host computer 8, so that the host computer 8 can obtain the electrostriction coefficient of the sample 3 under test based on the multiple interference fringes.

[0085] Optionally, in some embodiments of this application, the voltage of the power supply 2 can be controlled by the host computer 8 to increase or decrease linearly, thereby causing the deformation of the sample 3 to increase or decrease linearly.

[0086] For example, the host computer 8 can control the output voltage of the power supply 2 to gradually increase by 10V, thereby causing a change in the deformation of the sample 3 under test every 10V interval, and acquiring the interference fringes corresponding to the current deformation. Furthermore, based on multiple interference fringes, the host computer 8 obtains the electrostriction coefficient of the sample 3 under test using the existing electrostriction coefficient calculation formula. For example, it can arbitrarily select the interference fringes generated when the deformation of the sample 3 under test changes for the i-th and j-th times, and then obtain the electrostriction coefficient of the sample 3 under test.

[0087] In some embodiments of this application, the host computer 8 can also input multiple interference fringes into MATLAB software to generate brightness curves, and then use Origin software to fit multiple brightness curves to obtain the linear correlation coefficient between the coordinate displacement of different interference fringes and the voltage value. Thus, the electrostriction coefficient of the sample 3 under test can be obtained using the electrostriction coefficient calculation formula provided in the above embodiments. Compared with only using two interference fringes before and after the deformation of the sample 3 under test, using multiple interference fringes corresponding to different deformations can more accurately obtain the electrostriction coefficient of the sample 3 under test.

[0088] Furthermore, such as Figure 9 As shown, the device also includes a support platform 9 and an iron frame platform 10.

[0089] The support platform 9 is used to place the sample to be tested 3 and the support block 4.

[0090] Multiple iron stands 10 are used to fix the light source 1, the light screen 6 and the image processing module 7 respectively.

[0091] Optionally, the height of the iron stand 10 is adjustable, and the height of the light source 1, the light screen 6, and the image processing module 7 can be adjusted by adjusting the height of the iron stand 10.

[0092] Furthermore, both the support platform 9 and the support block 4 are 3D printed parts.

[0093] Preferably, the height of the support block 4 is equal to the height of the sample 3 under test when the deformation is 0, so that the reflector 5 can be placed horizontally on the surface of the sample 3 under test and the support block 4.

[0094] Furthermore, the size of the contact area between the reflector 5 and the sample 3 is smaller than the size of the surface of the sample 3 on the side in contact with the reflector 5.

[0095] It is worth noting that the size of the contact area between the reflector 5 and the sample 3 is the length of the contact area along the direction connecting the center point of the sample 3 and the center point of the support block 4. For example, when the contact area between the reflector 5 and the sample 3 is circular, the size of the contact area is the diameter of the contact area; when the contact area between the reflector 5 and the sample 3 is square, the size of the contact area is the side length of the contact area.

[0096] For example, such as Figure 8 and Figure 9As shown, the reflector 5 is gently placed on the edge of the sample 3 to be tested. This avoids the problem that the uneven electrostriction coefficient of the sample 3 to be tested causes different deformations at different positions under voltage excitation, which would lead to inaccurate measurement results. During measurement, by changing the contact area between the sample 3 to be tested and the reflector 5, the electrostriction coefficient at different positions of the sample 3 to be tested can be accurately measured.

[0097] Furthermore, when the sample 3 to be tested is a piezoelectric ceramic tube, the positive terminal of the power supply 2 is connected to the inner wall of the piezoelectric ceramic tube, and the negative terminal of the power supply 2 is connected to the outer wall of the piezoelectric ceramic tube.

[0098] The size of the contact area between the reflector 5 and the piezoelectric ceramic tube is smaller than the wall thickness of the piezoelectric ceramic tube.

[0099] In a specific example of this application, the sample to be tested 3 is a piezoelectric ceramic tube with an outer diameter of 24 mm, an inner diameter of 20 mm, and a height of 23 mm. The reflector 5 has a length of 50 mm and a width of 40 mm. The diameter of the contact area between the reflector 5 and the sample to be tested 3 is less than 2 mm.

[0100] The electrostriction coefficient measuring device based on Loewe mirror interferometry provided in this application is simple in structure, easy to assemble, and low in cost. It can effectively acquire the interference fringes generated by the deformation of the sample under different voltages, allowing the determination of its electrostriction coefficient. The device is also characterized by its simple operation and repeatable results, promoting practical teaching. It is portable, easy to disassemble and assemble, and suitable for demonstration in popular science lectures on physics and optics. Furthermore, this device can be applied to industrial inspection. By accurately measuring the electrostriction coefficient of the material under test, problems in the product manufacturing process can be detected in a timely manner, improving product reliability and durability, ensuring consistency in product quality and performance, enabling rapid inspection on the production line, and significantly improving industrial production efficiency and competitiveness.

[0101] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. An electrostrictive coefficient measuring apparatus based on the Lohoe mirror interference method, characterized by comprising: include: A light source for emitting laser light, such that the laser light is incident on the reflector at a grazing angle of incidence; A power supply, connected to the sample under test, is used to apply voltage to the sample under test, thereby changing the deformation of the sample under test; The support block is located on the same horizontal plane as the sample to be tested; A reflector is placed on the surface of the sample to be tested and the support block, with one end in contact with the sample to be tested and the other end in contact with the support block; Used to reflect the laser, and output a first reflected beam before the deformation of the sample under test changes, and output a second reflected beam after the deformation of the sample under test changes; A light screen is used to generate a first interference fringe based on the interference light of the first reflected beam and the laser, and to generate a second interference fringe based on the interference light of the second reflected beam and the laser. An image processing module, connected to a host computer, is used to acquire and amplify the first interference fringe and the second interference fringe, and send the first interference fringe and the second interference fringe to the host computer; The host computer is used to obtain the electrostriction coefficient of the sample under test based on the first interference fringe and the second interference fringe.

2. The electrostrictive coefficient measuring apparatus based on the Linnik interferometry method according to claim 1, characterized in that, The host computer is connected to the power supply and is used to send control signals to the power supply to control the voltage of the power supply to change, thereby changing the deformation of the sample to be tested.

3. The electrostrictive coefficient measuring apparatus based on the Linnik interferometry method according to claim 1, wherein Also includes: A support platform for placing the sample to be tested and the support block; Multiple iron frames are used to fix the light source, the light screen and the image processing module, respectively.

4. The electrostrictive coefficient measuring apparatus based on the Linnik interferometry method according to claim 3, characterized in that, Both the support platform and the support block are 3D printed parts.

5. The electrostrictive coefficient measuring apparatus based on the Linnik interferometry method according to claim 1, wherein The height of the support block is equal to the height of the sample under test when the deformation is 0, so that the reflector can be placed horizontally on the surface of the sample under test and the support block.

6. The electrostrictive coefficient measurement apparatus based on the Linnik interferometry method according to claim 1, characterized in that, The size of the area where the reflector contacts the sample under test is smaller than the size of the surface of the sample under test that contacts the reflector.

7. The electrostrictive coefficient measuring apparatus based on the Linnik interferometry method according to claim 1, wherein When the sample to be tested is a piezoelectric ceramic tube The positive terminal of the power supply is connected to the inner wall of the piezoelectric ceramic tube, and the negative terminal of the power supply is connected to the outer wall of the piezoelectric ceramic tube. The size of the contact area between the reflector and the piezoelectric ceramic tube is smaller than the wall thickness of the piezoelectric ceramic tube.

8. The electrostrictive coefficient measuring apparatus based on the Linnik interferometry method according to claim 7, characterized in that, The piezoelectric ceramic tube has an outer diameter of 24 mm, an inner diameter of 20 mm, and a height of 23 mm. The reflector is 50mm long and 40mm wide; The diameter of the contact area between the reflector and the sample under test is less than 2 mm.

9. The electrostrictive coefficient measuring apparatus based on the Linnik interferometry method according to claim 1, characterized in that, The image processing module is a digital microscope, a CCD camera, or a high-speed camera.

10. The electrostrictive coefficient measuring apparatus based on the Linnik interferometry method according to claim 1, characterized in that, The power supply is a DC regulated power supply.

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