Dynamic magnetostriction coefficient experimental instrument

Abstract

The invention discloses a dynamic magnetostriction coefficient experimental instrument which adopts a laser interference principle to measure the expansion and contraction amount and the dynamic magnetostriction coefficient of a magnetostriction material, and polarization elements such as a 1 / 2 lambda wave plate, a 1 / 4 lambda wave plate and PBS are added into a traditional Michelson interferometer to realize accurate regulation and control of a laser beam splitting ratio; a 4f system is used for focusing laser on a reflecting film on the surface of the magnetostrictive material to avoid scattering and light spot distortion of the reflecting film on the surface of the magnetostrictive material; the method comprises the following steps: clamping a magnetostrictive material by adopting a sample bracket, providing a uniform alternating magnetic field and controlling the temperature of the magnetostrictive material; the photoelectric sensor built based on a TIA amplification circuit and a photodiode realizes high-speed changing light intensity measurement. The experimental device can verify a plurality of dynamic characteristics of the magnetostriction material, has the advantages of low cost, wide frequency response and high precision, and has important value for exploring the frequency-doubled effect of magnetostriction and researching the influence of magnetic field frequency, intensity and environment temperature on the dynamic magnetostriction coefficient of a sample.

Description

Technical Field

[0001] The invention relates to a physical experiment device, in particular to a dynamic magnetostriction coefficient experiment instrument. Background Art

[0002] In the prior art, magnetostriction is an important property of some magnetic materials (such as ferrite, Terfenol-D alloy, etc.), and its research history is long. K.Linnemann, Marcelo J.Dapino and others have deeply explored the theoretical model of magnetostrictive materials; Valadkhan S and others compared and summarized the theoretical model of magnetostriction and studied the relationship between the magnetic permeability and stress of magnetostrictive materials; De Lacheisserie, E. and others took the lead in accurately measuring the magnetostriction coefficient. At the same time, magnetostrictive properties have important applications in displacement measurement, high-power sonar, ultrasonic transmitters, etc. and are a hot research direction.

[0003] In addition, magnetostriction also limits the use of magnetic components to a certain extent. Magnetic components such as toroidal inductors and transformers are widely used in communications, power transmission, electronic equipment and other fields. However, under the action of high-frequency alternating current, their magnetostriction effect may cause heating problems and resonance, thus affecting the performance and life of the components. In order to reduce these negative effects, it is very important to avoid the resonance phenomenon between magnetic components and external magnetic fields.

[0004] At the same time, in the current undergraduate "University Physics Experiment" course, although there have been experiments on measuring the hysteresis loop of magnetic materials, experimental exploration of other important properties of magnetic materials such as Curie point and dynamic magnetostriction coefficient has not yet been involved. This is not conducive to students' understanding of these abstract concepts, and is not conducive to students establishing a clear physical image of common effects of magnetostrictive materials such as the Joule effect and Villari effect.

[0005] Since the magnetostriction of general magnetic materials is relatively small (at the ppm level), a high-precision measurement device is required to achieve it.

[0006] There are many teaching instruments for studying the properties of magnetostrictive materials. Existing experimental devices measure the magnetostriction of materials based on the principles of equal-thickness interferometers and Michelson interferometers. Under an alternating magnetic field, magnetostrictive materials will vibrate with the magnetic field. However, the above-mentioned devices mainly observe the magnitude of magnetostriction by directly observing the throughput of interference fringes. When the magnetostrictive material is in an alternating magnetic field, the material vibrates, and the interference fringes change extremely quickly, exceeding the response frequency of the human eye. Therefore, it is still challenging to achieve high-sensitivity and high-precision dynamic magnetostriction measurements and study the related characteristics of dynamic magnetostriction. Summary of the invention

[0007] The purpose of the present invention is to provide a dynamic magnetostriction coefficient tester in view of the deficiencies of the prior art. The present invention is an experimental device for measuring the expansion and contraction amount and dynamic magnetostriction coefficient of magnetostrictive materials using the principle of laser interference. The present invention adds polarization elements such as 1 / 2λ wave plate, 1 / 4λ wave plate, PBS, etc. to the traditional Michelson interferometer to achieve precise control of the laser beam splitting ratio, greatly improving the interference contrast; the 4f system is used to focus the laser on the reflective film on the surface of the magnetostrictive material to avoid scattering and spot distortion of the reflective film on the surface of the magnetostrictive material, thereby accurately obtaining the expansion and contraction amount and dynamic magnetostriction coefficient of the magnetostrictive material;

[0008] The setting of the sample holder can stably clamp the magnetostrictive material, provide a uniform alternating magnetic field for the magnetostrictive material, and control the temperature of the magnetostrictive material; based on the construction of the TIA amplifier circuit and the photodiode in the photoelectric sensor, high-speed light intensity measurement can be achieved.

[0009] The present invention can verify multiple dynamic characteristics of magnetostrictive materials, such as: the frequency doubling effect of magnetostriction, the frequency characteristics and temperature characteristics of the dynamic magnetostriction coefficient, and measure the Young's modulus of magnetostrictive materials; it can measure high-frequency vibrations of tens of kilohertz, and the ultimate accuracy can reach the angstrom level.

[0010] The present invention not only helps students to establish physical images about the properties related to magnetic materials, but also improves students' ability to integrate various experimental techniques.

[0011] The specific technical solution for achieving the purpose of the present invention is:

[0012] A dynamic magnetostriction coefficient experimental instrument, which features include a polarized helium-neon laser, an attenuation plate, a first dielectric film reflector, a first convex lens, a second convex lens, a second dielectric film reflector, a 1 / 2λ wave plate, a first 1 / 4λ wave plate, a third dielectric film reflector, a fourth dielectric film reflector, a polarization beam splitter, a second 1 / 4λ wave plate, a fifth dielectric film reflector, a sixth dielectric film reflector, a sample holder, a function signal generator, a power amplifier, a metal film resistor, a digital oscilloscope, a temperature controller, a polarizer, an aperture stop, a photoelectric sensor and a DC power supply;

[0013] The polarized helium-neon laser is provided with an attenuation plate, a first dielectric film reflector, a first convex lens, a second convex lens, and a second dielectric film reflector in sequence along the direction of the laser emission light path;

[0014] The 1 / 2λ wave plate, the first 1 / 4λ wave plate, the second 1 / 4λ wave plate and the polarizer are respectively arranged along the optical path orthogonal to the four sides of the polarization beam splitter;

[0015] The 1 / 2λ wave plate is optically connected to the second dielectric film reflector;

[0016] The first 1 / 4λ wave plate is sequentially connected to the third dielectric film reflector and the fourth dielectric film reflector optically;

[0017] The second 1 / 4λ wave plate is sequentially connected to the optical paths of the fifth dielectric film reflector and the sixth dielectric film reflector;

[0018] The polarizer is connected to the aperture stop optical path;

[0019] The DC power supply is electrically connected to the photoelectric sensor, and the photoelectric sensor is connected to the aperture stop optical path;

[0020] The photoelectric sensor is electrically connected to the digital oscilloscope;

[0021] The sample holder is provided with an excitation coil, a silicone heating ring and a magnetostrictive material;

[0022] The surface of the magnetostrictive material is coated with a reflective film, and the reflective film is optically connected to the sixth dielectric film reflector;

[0023] The temperature controller is electrically connected to the silicone heating coil on the sample holder;

[0024] The function signal generator is electrically connected to the power amplifier, and the power amplifier is electrically connected to the excitation coil and the digital oscilloscope on the sample holder respectively;

[0025] The metal film resistor, the power amplifier and the excitation coil are connected in series.

[0026] The metal film resistor is connected in parallel with the digital oscilloscope.

[0027] The first convex lens and the second convex lens form a 4f system.

[0028] The sample holder also includes an aluminum holder front end, an aluminum holder rear end, an outer quartz tube and an inner quartz tube; the outer quartz tube, the silicone heating ring, the excitation coil, the inner quartz tube and the magnetostrictive material are arranged in sequence from the outside to the inside in a tubular shape, and the two ends of the tubular shape are respectively arranged on the aluminum holder front end and the aluminum holder rear end.

[0029] The photoelectric sensor is composed of a transimpedance TIA amplifier module, a base, a silicon photodiode, a BNC-J / SMA-J male jumper and a DuPont line; the transimpedance TIA amplifier module is arranged on the base; the transimpedance TIA amplifier module is provided with a power supply port, an input terminal and an SMA interface,

[0030] The silicon photodiode and one end of the BNC-J / SMA-J male jumper are connected to the input end and the SMA interface on the transimpedance TIA amplifier module in sequence, and the other end of the BNC-J / SMA-J male jumper is connected to the digital oscilloscope;

[0031] One end of the DuPont line is connected to the power supply port of the transimpedance TIA amplifier module, and the other end is connected to a DC power supply.

[0032] Compared with the traditional technology, the beneficial effects of the present invention are:

[0033] The present invention directly measures the central light intensity of the zero-order fringe of the equal-inclination interference fringe to calculate the magnitude of the dynamic magnetostriction, which can greatly improve the experimental measurement accuracy and measure the vibration amplitude of the magnetostrictive material during high-frequency vibration. Experimental verification shows that the present invention can measure high-frequency vibrations of tens of kilohertz, with a limit accuracy of angstroms. The present invention uses a 4f system to focus the laser on the reflective film on the surface of the magnetostrictive material to avoid scattering and spot distortion of the reflective film on the surface of the magnetostrictive material, thereby improving the measurement accuracy of the device; by introducing a 1 / 2λ wave plate, a 1 / 4λ wave plate, and a PBS to adjust the laser beam splitting ratio, balance the loss of light intensity caused by the reflective film in the detection optical path, thereby improving the interference contrast and the measurement accuracy of the instrument.

[0034] At the same time, a silicone heating ring is added to the sample holder, which can also change the temperature of the magnetostrictive material and study the temperature characteristics of the dynamic magnetostriction coefficient, so as to study multiple characteristics of the magnetostrictive material.

[0035] Compared with the traditional method of measuring magnetostriction coefficient using the interference principle, the present invention has the advantages of low cost, wide frequency response and high precision. It can be used to explore the frequency doubling effect of magnetostriction and study the influence of magnetic field frequency, intensity and ambient temperature on the dynamic magnetostriction coefficient of the sample. It has important value in the research, teaching and industrial production of magnetic materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a structural schematic diagram of the present invention;

[0037] Figure 2 It is a schematic diagram of the structure of the photoelectric sensor;

[0038] Figure 3 Schematic diagram of the sample holder structure. DETAILED DESCRIPTION

[0039] The present invention is further described in detail with reference to the following specific examples and drawings. The process, conditions, experimental methods, etc. for implementing the present invention, except for the contents specifically mentioned below, are all common knowledge and common common sense in the art and are not particularly limited by the present invention.

[0040] The present invention comprises a polarized helium-neon laser 1, an attenuation plate 2, a first dielectric film reflector 3, a first convex lens 4, a second convex lens 5, a second dielectric film reflector 6, a 1 / 2λ wave plate 7, a first 1 / 4λ wave plate 8, a third dielectric film reflector 9, a fourth dielectric film reflector 10, a polarization beam splitter 11, a second 1 / 4λ wave plate 12, a fifth dielectric film reflector 13, a sixth dielectric film reflector 14, a sample holder 15, a function signal generator 16, a power amplifier 17, a metal film resistor 18, a digital oscilloscope 19, a temperature controller 20, a polarizer 21, an aperture stop 22, a photoelectric sensor 23 and a DC power supply 24.

[0041] Example

[0042] See also Figure 1 , Figure 2 and Figure 3 , the outer quartz tube 35, the silicone heating ring 36, the excitation coil 37, the inner quartz tube 38 and the magnetostrictive material 39 are arranged in sequence from the outside to the inside in a tubular shape; the two ends of the tubular shape are respectively arranged on the front end 33 of the aluminum bracket and the rear end 34 of the aluminum bracket; the reflective film is connected to the optical path of the sixth dielectric film reflector 14 by adjustment; the temperature controller 20 is electrically connected to the silicone heating ring 36 on the sample holder 15; the function signal generator 16 is electrically connected to the power amplifier 17, the power amplifier 17 is connected in series with the excitation coil 37 and the metal film resistor 18 on the sample holder 15, and the metal film resistor 18 is connected in parallel with the digital oscilloscope 19.

[0043] See also Figure 1 , Figure 2 , turn on the polarized helium-neon laser 1, turn on the DC power supply 24; the voltage signal at both ends of the metal film resistor 18 is passed into the CH3 port of the digital oscilloscope 19, and the two signals of the photoelectric sensor 23 are respectively passed into the CH1 and CH2 interfaces of the digital oscilloscope 19, the CH1 channel adopts DC coupling, and the CH2 channel adopts AC coupling.

[0044] See also Figure 1 , rotate the attenuation plate 2 to attenuate the light intensity, and adjust the horizontal translation stage under the second convex lens 5 to change the focal length of the 4f system so that the laser focus falls accurately on the sample reflective film.

[0045] See also Figure 1 , Figure 2 Then, place the light screen in front of the fourth dielectric film reflector 10 to block the light signal, observe the light intensity signal detected by the photoelectric sensor 23, and rotate the second 1 / 4λ wave plate 12 to maximize the light intensity signal. Then remove the light screen in front of the fourth dielectric film reflector 10, place the light screen in front of the sample holder 15 to block the light signal, observe the light intensity signal detected by the photoelectric sensor 23, rotate the first 1 / 4λ wave plate 8 to maximize the light intensity signal, and remove the light screen.

[0046] See also Figure 1 Then, the main axis of the 1 / 2λ wave plate 7 is rotated, and the output light intensity of the optical path where the fourth dielectric film reflector 10 is located and the optical path where the sample holder 15 is located are measured with an optical power meter, so that the output light intensity of the two optical paths is basically consistent.

[0047] See also Figure 1 , Figure 2 , Figure 3 , fine-tune the horizontal displacement stage below the fourth dielectric film reflector 10 to slightly change the optical path of the optical path, and use the horizontal cursor of the digital oscilloscope 19 to measure the interference maximum signal I displayed on the CH1 channel max and the interference minimum signal I min The interference light intensity I satisfies:

[0048]

[0049] Where A and B are unknown coefficients, Δl is the sample expansion, λ is the wavelength of the laser, and φ0 is the initial phase. max with I min Calculate the coefficients in the expression:

[0050]

[0051] Next, turn on the function signal generator 16 and the power amplifier 17. The function signal generator 16 outputs a sinusoidal AC signal with a frequency of about twice the sample resonant frequency. Slowly rotate the output knob of the power amplifier 17 to appropriately amplify the signal and ensure that the output signal is within the rated operating voltage range of the metal film resistor 18 and the excitation coil 37.

[0052] Finally, the CH2 signal I in the digital oscilloscope 19 is derived.

[0053]

[0054] The magnetostriction Δl of the sample is calculated. By calibrating the relationship between the magnetic field of the excitation coil 37 and the input current with a Gauss meter, the alternating driving magnetic field H in the excitation coil 37 under experimental conditions can be obtained. AC The size of the sample is then obtained to obtain the dynamic magnetostriction coefficient d, which satisfies

[0055]

[0056] where ε AC is the alternating strain of the sample.

[0057] Further description of the embodiments of the present invention

[0058] See also Figure 1 , Figure 3In order to make the magnetostrictive material 39 reflect laser light, the surface of the magnetostrictive material 39 of the present invention is coated with a reflective film, and the reflective film is connected to the optical path of the sixth dielectric film reflector 14 by adjustment to add it to the interference optical path.

[0059] See also Figure 1 , Figure 3 , the temperature controller 20 is electrically connected to the silicone heating ring 36 on the sample holder 15; the function signal generator 16 is electrically connected to the power amplifier 17, and the power amplifier 17 is electrically connected to the excitation coil 37 and the digital oscilloscope 19 on the sample holder 15 respectively.

[0060] See also Figure 1 , Figure 3 The function signal generator 16 outputs a sinusoidal AC signal, which is amplified by the power amplifier 17 and applied to both ends of the excitation coil 37 and the metal film resistor 18. The voltage signal at both ends of the metal film resistor 18 is passed to the digital oscilloscope 19 through a coaxial cable to monitor the sinusoidal AC signal applied to both ends of the excitation coil 37 in real time.

[0061] See also Figure 1 A linearly polarized laser with a stable power and a wavelength of 632.8 nm is emitted by a polarized helium-neon laser 1. The laser light intensity is attenuated by an attenuation plate 2. Subsequently, the laser enters a 4f system composed of a first convex lens 4 and a second convex lens 5. A horizontal displacement stage is installed under the second convex lens 5. The focal length of the laser in the 4f system can be adjusted by adjusting the horizontal displacement stage.

[0062] See also Figure 1 , because the polarizer 21, aperture diaphragm 22 and photoelectric sensor of the present invention are coaxially arranged; wherein the polarizer 21 is used to allow the reference light in the horizontal polarization state to interfere with the detection light in the vertical polarization state; the aperture diaphragm 22 is used to block the high-order interference orders of the equal-inclination interference fringes, leaving only the zero-order interference fringes.

[0063] See also Figure 1 The present invention uses a polarization beam splitter prism of a polarizer 21 to separate the laser light emitted by the polarized helium-neon laser 1 into a detection light path and a reference light path of polarization states, and uses polarization to adjust the light intensity of the two light paths to improve the interference contrast;

[0064] See also Figure 1 , Figure 3 In addition, the reflectivity of the dielectric film reflector selected in this embodiment is 99%, and the reflectivity of the reflective film is 78%. Since the reference light is reflected by the fourth dielectric film reflector 10, and the detection light is reflected by the reflective film on the magnetostrictive material 39, the light intensity between the reference light and the detection light is not equal. The splitting ratio of the reference light and the detection light is adjusted by controlling the 1 / 2λ wave plate 7 and the polarization beam splitter 11 to control the light intensity of the two light paths to be equal.

[0065] See also Figure 1 Since the polarization beam splitter 11 transmits horizontally polarized light and reflects vertically polarized light, when a beam of linearly polarized light is incident on the polarization beam splitter 11, its horizontal polarization component and vertical polarization component are effectively separated. Therefore, it is only necessary to rotate the main axis of the 1 / 2λ wave plate 7 to rotate the laser polarization plane. By adjusting the polarization degree of the linearly polarized light, the splitting ratio of the laser is adjusted, thereby improving the interference contrast.

[0066] See also Figure 1 The polarization beam splitter prism also plays the role of beam combining. After the laser beam is split, it will be reflected by the sample or the reflector and will re-enter the polarization beam splitter prism.

[0067] See also Figure 1 , a first 1 / 4λ wave plate 8 and a second 1 / 4λ wave plate 12 are placed on the detection light path and the reference light path, so that each laser beam will pass through the 1 / 4λ wave plate twice, which is equivalent to passing through the 1 / 2λ wave plate once. The main axis of the 1 / 4λ wave plate is adjusted so that the original horizontal polarized light becomes vertical polarized light, and the original vertical polarized light becomes horizontal polarized light. Therefore, the transmission and reflection properties of the polarization beam splitter prism for the detection light and the reference light are exchanged, so that the two laser beams can converge in front of the photoelectric sensor 23 to interfere.

[0068] See also Figure 1 A horizontal displacement stage is installed below the fourth dielectric film reflector 10 to facilitate fine adjustment of the optical path of the reference optical path.

[0069] See also Figure 1 , Figure 3 Since the surface of the magnetostrictive material 39 is coated with a reflective film, the detection light path is reflected by the surface of the magnetostrictive material 39, loaded with the phase signal of the sample vibration, and interferes with the reference light path. By interfering with the change of the light intensity signal of the zero-order fringe, the dynamic magnetostriction of the magnetostrictive material 39 is obtained.

[0070] See also Figure 1 , Figure 3, since an attenuation plate 2, a first dielectric film reflector 3, a first convex lens 4, a second convex lens 5 and a second dielectric film reflector 6 are sequentially arranged along the laser emission direction of the polarized helium-neon laser 1; wherein: the attenuation plate 2 is used to continuously adjust the light intensity of the output laser; the first dielectric film reflector 3 and the second dielectric film reflector 6 are symmetrically arranged at an angle of 45° with the laser, and are used to adjust the laser pitch angle and position so that it can overlap with the detection light when the beam is combined; at the same time, a certain interval is arranged between the first dielectric film reflector 3 and the second dielectric film reflector 6 to provide A certain optical delay makes the optical path difference between the detection light and the reference light basically consistent, thereby improving the interference contrast; the first convex lens 4 and the second convex lens 5 form a 4f system to adjust the focal length of the laser in the optical path. In order to improve the distortion and speckle of the reflected light spot caused by the uneven surface of the reflective film, the 4f system composed of the first convex lens 4 and the second convex lens 5 is required. By adjusting the focal length of the 4f system, the laser is converged at a point of the reflective film of the magnetostrictive material 39 to obtain a better reflection effect; at the same time, the 4f system also acts as a beam expander to produce equal-inclination interference fringes;

[0071] See also Figure 1 In this embodiment, the 1 / 2λ wave plate 7 uses a 633nm half-wave plate to change the polarization direction of the laser emitted by the polarized helium-neon laser 1, thereby changing the ratio of the intensity of the horizontal polarization component and the vertical polarization component of the laser; the 1 / 2λ wave plate 7 is combined with the polarization beam splitter 11 to achieve continuous regulation of the laser beam splitting ratio, thereby achieving precise regulation of the intensity of the detection light and the reference light.

[0072] See also Figure 1 , Figure 3 The fifth dielectric film reflector 13 and the sixth dielectric film reflector 14 in the detection light path are used to adjust the pitch angle and position of the detection light so that the detection light is vertically incident on the magnetostrictive material 39, and the incident light source is reflected by the magnetostrictive material 39 and returns to the original path, and is combined with the reference light at the polarization beam splitter 11.

[0073] See also Figure 1 The first 1 / 4λ wave plate 8 and the second 1 / 4λ wave plate 12 of the present invention are selected as 633nm 1 / 4λ wave plates, which are used to change the polarization state of the laser and realize the mutual conversion between linear polarized light and circular polarized light, thereby assisting the polarization beam splitter 11 to perform laser beam combining.

[0074] Application of photoelectric sensors and DC power supplies:

[0075] See also Figure 1 , Figure 2 The photoelectric sensor 23 is used to measure the light intensity of the zero-order interference fringes, thereby inferring the magnitude of the magnetostriction amount and realizing the measurement of dynamic magnetostriction;

[0076] The DC power supply 24 is used to supply power to the photoelectric sensor 23 , and the supply voltage is between 12V and 15V.

[0077] Application of function signal generator and power amplifier:

[0078] See also Figure 1 The function signal generator 16 and the power amplifier 17 together form a power supply device for the excitation coil in the sample holder 15. The function signal generator can provide AC signals of different frequencies and waveforms; the power amplifier amplifies the AC signal, so that the excitation coil generates an AC magnetic field of 10kHz and 5mT, causing the magnetostrictive material to vibrate at a high frequency.

[0079] Application of digital oscilloscope and temperature controller:

[0080] See also Figure 1 , Figure 3 The digital oscilloscope 19 is used to receive the photoelectric signals measured by the photoelectric sensor 23 and the metal film resistor 18, and to store and export the experimental data for subsequent data analysis.

[0081] The temperature controller 20 is used to measure and control the temperature of the silicone heating coil 36 on the sample holder 15. The temperature range of the silicone heating coil is 30 to 100 degrees Celsius. The temperature of the magnetostrictive material 39 is changed by adjusting the temperature controller 20 to study the temperature characteristics of the dynamic magnetostriction coefficient.

[0082] Applications of Metal Film Resistors:

[0083] See also Figure 1 The metal film resistor 18 is disposed between the power amplifier 17 and the excitation coil 37 , and the resistance of the metal film resistor 18 is set to 1Ω to achieve indirect measurement of the current in the excitation coil 37 , thereby obtaining the magnitude of the AC magnetic induction intensity in the excitation coil 37 .

[0084] Focus adjustment of 4f system:

[0085] See also Figure 1 , Figure 3 Since the first convex lens 4 and the second convex lens 5 of the present invention form a 4f system, when working, the focus of the 4f system is adjusted to the reflective film on the surface of the magnetostrictive material 39 in the sample holder 15, thereby effectively reducing the spot distortion and light intensity loss caused by the uneven and rough surface of the reflective film, thereby improving the interference contrast of the interference fringes and improving the measurement accuracy of the device.

[0086] Applications of photoelectric sensors:

[0087] See also Figure 1 , Figure 2The photoelectric sensor 23 is used to output the amplified photoelectric signal. At the same time, the amplified photoelectric signal is divided into an AC signal and a DC signal by a BNC-J / SMA-J male jumper 29, and enters the digital oscilloscope 19 respectively, which is convenient for subsequent data processing; one end of the DuPont line 31 on the photoelectric sensor 23 is connected to the power supply port 30 of the transimpedance TIA amplifier module 25, and the other end is connected to the DC power supply 24 to realize power supply to the photoelectric sensor 23.

[0088] See also Figure 1 , Figure 2 , the photoelectric sensor adopts a transimpedance TIA amplifier module 25 to improve the sensitivity and signal-to-noise ratio of the sensor; the TIA amplifier circuit is a universal broadband amplifier circuit, which inputs a current of nA and outputs a voltage of several volts to achieve a gain of one hundred thousand times; the transimpedance TIA amplifier module 25 used in this embodiment has a response bandwidth of 0-500kHz, which can basically meet the measurement requirements of high-frequency vibration. The silicon photodiode 27 is directly installed at the input end 32 of the transimpedance TIA amplifier module 25 to detect the light intensity signal; the silicon photodiode 27 used in this embodiment has a good response to lasers of 400 to 800nm, which meets the light intensity measurement of helium-neon lasers; the DC power supply 24 is connected to the power supply port 31 of the photoelectric sensor to power the photoelectric sensor; the signal is led out from the SMA interface 28 through the BNC-J / SMA-J male jumper 29, and is divided into two signals that are passed into different channels of the digital oscilloscope 19; the two signals are respectively DC coupled and AC coupled to measure the low-frequency and high-frequency components in the collected light intensity signal.

[0089] The protection content of the present invention is not limited to the above embodiments. Without departing from the spirit and scope of the inventive concept, changes and advantages that can be thought of by those skilled in the art are included in the present invention and are protected by the attached claims.

Claims

1. A dynamic magnetostriction coefficient tester, characterized in that: It comprises a polarized helium-neon laser (1), an attenuation plate (2), a first dielectric film reflector (3), a first convex lens (4), a second convex lens (5), a second dielectric film reflector (6), a 1 / 2λ wave plate (7), a first 1 / 4λ wave plate (8), a third dielectric film reflector (9), a fourth dielectric film reflector (10), a polarization beam splitter (11), a second 1 / 4λ wave plate (12), a fifth dielectric film reflector (13), a sixth dielectric film reflector (14), a sample holder (15), a function signal generator (16), a power amplifier (17), a metal film resistor (18), a digital oscilloscope (19), a temperature controller (20), a polarizer (21), an aperture stop (22), a photoelectric sensor (23) and a DC power supply (24); The polarized helium-neon laser (1) is provided with an attenuation plate (2), a first dielectric film reflector (3), a first convex lens (4), a second convex lens (5) and a second dielectric film reflector (6) in sequence along the direction of the laser emission light path; A 1 / 2λ wave plate (7), a first 1 / 4λ wave plate (8), a second 1 / 4λ wave plate (12) and a polarizing plate (21) are respectively arranged along the optical path orthogonally to the four sides of the polarization beam splitter (11); The 1 / 2λ wave plate (7) is optically connected to the second dielectric film reflector (6); The first 1 / 4λ wave plate (8) is optically connected to the third dielectric film reflector (9) and the fourth dielectric film reflector (10) in sequence; The second 1 / 4λ wave plate (12) is optically connected to the fifth dielectric film reflector (13) and the sixth dielectric film reflector (14) in sequence; The polarizing plate (21) is optically connected to the aperture stop (22); The DC power supply (24) is electrically connected to the photoelectric sensor (23), and the photoelectric sensor (23) is optically connected to the aperture stop (22); The photoelectric sensor (23) is electrically connected to the digital oscilloscope (19); The sample holder (15) is provided with an excitation coil (37), a silicone heating ring (36) and a magnetostrictive material (39); The surface of the magnetostrictive material (39) is coated with a reflective film, and the reflective film is optically connected to the sixth dielectric film reflector (14); The temperature controller (20) is electrically connected to the silica gel heating ring (36) on the sample holder (15); The function signal generator (16) is electrically connected to a power amplifier (17), and the power amplifier (17) is electrically connected to an excitation coil (37) and a digital oscilloscope (19) respectively on the sample holder (15); The metal film resistor (18), the power amplifier (17) and the excitation coil (37) are connected in series; The metal film resistor (18) is connected in parallel with the digital oscilloscope (19).

2. A dynamic magnetostriction coefficient tester according to claim 1, characterized in that: The first convex lens (4) and the second convex lens (5) form a 4f system.

3. A dynamic magnetostriction coefficient tester according to claim 1, characterized in that: The sample support (15) further comprises an aluminum support front end (33), an aluminum support rear end (34), an outer quartz tube (35) and an inner quartz tube (38); the outer quartz tube (35), a silicone heating ring (36), an excitation coil (37), an inner quartz tube (38) and a magnetostrictive material (39) are arranged in sequence from the outside to the inside in a tubular shape, and the two ends of the tubular shape are respectively arranged on the aluminum support front end (33) and the aluminum support rear end (34).

4. A dynamic magnetostriction coefficient tester according to claim 1, characterized in that: The photoelectric sensor (23) is composed of a transimpedance TIA amplifier module (25), a base (26), a silicon photodiode (27), a BNC-J / SMA-J male jumper (29) and a DuPont line (31); the transimpedance TIA amplifier module (25) is arranged on the base (26); the transimpedance TIA amplifier module (25) is provided with a power supply port (30), an input end (32) and an SMA interface (28); one end of the silicon photodiode (27) and the BNC-J / SMA-J male jumper (29) are connected to the input end (32) and the SMA interface (28) on the transimpedance TIA amplifier module (25) in sequence, and the other end of the BNC-J / SMA-J male jumper (29) is connected to a digital oscilloscope (19); one end of the DuPont line (31) is connected to the power supply port (30) of the transimpedance TIA amplifier module (25), and the other end is connected to a direct current power supply (24).

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