Dynamic magnetostriction coefficient tester

Abstract

The application discloses a kind of dynamic magnetostrictive coefficient experimental apparatus, using laser interference principle measurement magnetostrictive material expansion and dynamic magnetostrictive coefficient, in traditional Michelson interferometer 1 / 2 lambda wave plate, 1 / 4 lambda wave plate, PBS polarization element is added to realize the accurate control of laser beam splitting ratio;Utilize 4f system to focus laser on the reflecting film on the surface of magnetostrictive material to avoid the scattering and spot distortion of the reflecting film on the surface of magnetostrictive material;Magnetostrictive material is clamped using sample support, uniform alternating magnetic field is provided and the temperature of magnetostrictive material is controlled;Photoelectric sensor based on TIA amplifying circuit and photodiode realizes the light intensity measurement of high-speed change.This experimental device can verify multiple dynamic characteristics of magnetostrictive material, the application has the advantages of low cost, wide frequency response and high precision, and has important value for exploring the frequency doubling effect of magnetostriction, studying the influence of magnetic field frequency, intensity and environmental temperature on the dynamic magnetostrictive coefficient of 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] Magnetostriction is a key property of some magnetic materials (such as ferrites and Terfenol-D alloys), and its research has a long history. K. Linnemann, Marcelo J. Dapino, and others have thoroughly explored theoretical models of magnetostrictive materials; Valadkhan S. and others compared and summarized theoretical models of magnetostriction, studying the relationship between the magnetic permeability and stress of magnetostrictive materials; and De Lacheisserie, E., and others pioneered the precise measurement of the magnetostriction coefficient. Magnetostriction also has important applications in displacement measurement, high-power sonar, and ultrasonic transmitters, and remains a hot research topic.

[0003] Furthermore, 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, and electronic equipment. However, under the influence of high-frequency alternating current, their magnetostrictive effect can cause heating and resonance, thereby affecting the performance and lifespan of the components. To minimize these negative effects, it is crucial to avoid resonance 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 the Curie point and dynamic magnetostriction coefficient has not yet been explored. 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] Currently, 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, achieving high-sensitivity and high-precision dynamic magnetostriction measurements and studying the related properties of dynamic magnetostriction still have certain challenges. Summary of the Invention

[0007] The purpose of the present invention is to provide a dynamic magnetostriction coefficient tester in response to 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; using the 4f system to focus the laser on the reflective film on the surface of the magnetostrictive material, avoiding 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 and temperature characteristics of the dynamic magnetostriction coefficient, and measure the Young's modulus of magnetostrictive materials. It can also measure high-frequency vibrations of tens of kilohertz with an ultimate accuracy of up to the angstrom level.

[0010] The present invention not only helps students establish a physical image of the relevant properties of 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 experiment instrument, characterized by comprising 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 He-Ne 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 optically connected to the third dielectric film reflector and the fourth dielectric film reflector in sequence;

[0017] The second 1 / 4λ wave plate is optically connected to the fifth dielectric film reflector and the sixth dielectric film reflector in sequence;

[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 ring 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, silicone heating ring, excitation coil, inner quartz tube and magnetostrictive material are arranged in a tubular shape from the outside to the inside, 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 port 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 wire is connected with a power supply port of the transimpedance TIA amplifier module, and the other end is connected with a direct current power supply.

[0032] Compared with the conventional technology, the application has the beneficial effects that:

[0033] The application directly measures the center light intensity of the zero-order fringe of the equal inclination interference fringe, thereby calculating the dynamic magnetostriction size, greatly improving the experimental measurement precision, and measuring the vibration amplitude of the magnetostriction material in high-frequency vibration. Through experiments, it is verified that the application can measure high-frequency vibration of tens of kilohertz, and the limit precision can reach the order of angstrom. The application focuses laser on the reflecting film on the surface of the magnetostriction material through the 4f system to avoid the scattering and spot distortion of the reflecting film on the surface of the magnetostriction material, and improves the measurement precision of the device; the laser beam splitting ratio is controlled by introducing the 1 / 2 lambda wave plate, the 1 / 4 lambda wave plate and the PBS, the loss of the reflecting film to the light intensity in the detection light path is balanced, and the interference contrast and the measurement precision of the instrument are improved.

[0034] Meanwhile, silica gel heating rings are added to the sample support, the temperature of the magnetostriction material can also be changed, the temperature characteristics of the dynamic magnetostriction coefficient can be studied, and multiple characteristics of the magnetostriction material can be studied.

[0035] Compared with the conventional technology, the application has the beneficial effects that: BRIEF DESCRIPTION OF DRAWINGS

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

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

[0038] Figure 3 It is a structural schematic diagram of the sample support. DETAILED DESCRIPTION

[0039] The application will be further described in detail in combination with the following specific embodiments and drawings. The process, condition, experimental method and the like for implementing the application are the general knowledge and common sense in the art, and the application does not have special limitations.

[0040] The present application comprises a polarized helium-neon laser 1, an attenuator 2, a first dielectric film mirror 3, a first convex lens 4, a second convex lens 5, a second dielectric film mirror 6, a 1 / 2 lambda wave plate 7, a first 1 / 4 lambda wave plate 8, a third dielectric film mirror 9, a fourth dielectric film mirror 10, a polarized light splitting beam splitter 11, a second 1 / 4 lambda wave plate 12, a fifth dielectric film mirror 13, a sixth dielectric film mirror 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 diaphragm 22, a photoelectric sensor 23 and a direct current power supply 24.

[0041] Embodiment

[0042] Referring to Figure 1 , Figure 2 and Figure 3 , the outer quartz tube 35, the silica gel heating ring 36, the excitation coil 37, the inner quartz tube 38 and the magnetostrictive material 39 are sequentially arranged in a tubular shape from the outside to the inside; the tubular ends are arranged on the aluminum support front end 33 and the aluminum support rear end 34, respectively; the light path of the reflective film is connected to the sixth dielectric film mirror 14 by adjustment; 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 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] Referring to Figure 1 , Figure 2 , turn on the polarized helium-neon laser 1 and the direct current power supply 24; the voltage signal between the two ends of the metal film resistor 18 is input into the CH3 port of the digital oscilloscope 19, and the two-way signal of the photoelectric sensor 23 is input into the CH1 and CH2 interfaces of the digital oscilloscope 19, respectively; the CH1 channel adopts a direct current coupling mode, and the CH2 channel adopts an alternating current coupling mode.

[0044] Referring to Figure 1 , rotate the attenuator 2 to attenuate the light intensity, and adjust the horizontal displacement table below the second convex lens 5 to change the focal length of the 4f system, so that the laser focal point accurately falls on the sample reflective film.

[0045] Referring to Figure 1 , Figure 2 , then, place a light screen in front of the fourth dielectric film mirror 10 to block the light signal, observe the light intensity signal detected by the photoelectric sensor 23, rotate the second 1 / 4 lambda wave plate 12 to make the light intensity signal maximum, remove the light screen in front of the fourth dielectric film mirror 10, place a light screen in front of the sample holder 15 to block the light signal, and observe the light intensity signal detected by the photoelectric sensor 23, rotate the first 1 / 4 lambda wave plate 8 to make the light intensity signal maximum, and remove the light screen.

[0046] See Figure 1 Then, rotate the main axis of the 1 / 2λ wave plate 7 and use an optical power meter to measure 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, so that the output light intensity of the two optical paths is basically consistent.

[0047] See 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 function signal generator 16 and power amplifier 17. Function signal generator 16 outputs a sinusoidal AC signal with a frequency approximately twice the sample's resonant frequency. Slowly turn the output knob of power amplifier 17 to appropriately amplify the signal and ensure that the output signal is within the rated operating voltage range of metal film resistor 18 and 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 current applied by the 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 obtained by 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 Figure 1 、 Figure 3In order to make the magnetostrictive material 39 reflect laser, the surface of the magnetostrictive material 39 of the present application is coated with a reflecting film, and the reflecting film is connected with the optical path of the sixth dielectric film mirror 14 by adjustment, so as to be added into the interference optical path.

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

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

[0061] Referring to Figure 1 The polarized helium-neon laser 1 emits linearly polarized laser with a wavelength of 632.8nm and a stable power, the laser is attenuated by the attenuator 2, then enters the 4f system composed of the first convex lens 4 and the second convex lens 5, and the horizontal displacement table is arranged below the second convex lens 5, and the focal length of the laser in the 4f system is adjusted by adjusting the horizontal displacement table.

[0062] Referring to Figure 1 Since the polarizer 21, the aperture diaphragm 22 and the photoelectric sensor are coaxially arranged, the polarizer 21 is used for causing the reference light in the horizontal polarization state to interfere with the detection light in the vertical polarization state, and the aperture diaphragm 22 is used for shielding high-order interference orders of the tilt interference fringes, and only leaving zero-order interference fringes.

[0063] Referring to Figure 1 The present application divides the laser emitted by the polarized helium-neon laser 1 into a detection light path and a reference light path through the polarization beam splitter of the polarizer 21, adjusts the light intensity of the two light paths by polarization, and improves the interference contrast;

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

[0065] See 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 laser beam splitting ratio is controlled, thereby improving the interference contrast.

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

[0067] See Figure 1 A first 1 / 4λ wave plate 8 and a second 1 / 4λ wave plate 12 are placed in the detection and reference light paths, respectively. This allows each laser beam to pass through the 1 / 4λ plate twice, equivalent to passing through the 1 / 2λ plate once. The 1 / 4λ wave plate's principal axis is adjusted to convert the originally horizontally polarized light into vertically polarized light, and vice versa. This causes the polarization beam splitter to swap the transmission and reflection properties of the detection and reference beams, allowing the two laser beams to converge in front of the photosensor 23 and interfere with each other.

[0068] See Figure 1 A horizontal translation stage is installed below the fourth dielectric film reflector 10 to facilitate fine-tuning of the optical path of the reference light path.

[0069] See 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. The dynamic magnetostriction of the magnetostrictive material 39 is obtained by interfering with the change in the light intensity signal of the zero-order fringe.

[0070] See 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° to the laser, and are used to adjust the laser pitch angle and position so that they can coincide with the detection light when the beam is combined; at the same time, a certain interval is set 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 on 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 Figure 1 In this embodiment, the 1 / 2λ wave plate 7 is a 633nm half-wave plate, which is used to change the polarization direction of the laser light emitted by the polarized He-Ne laser 1, thereby changing the ratio of the intensity of the horizontal polarization component to the vertical polarization component of the laser light; 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 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 Figure 1 The first 1 / 4λ wave plate 8 and the second 1 / 4λ wave plate 12 of the present invention use 633nm 1 / 4λ wave plates to change the polarization state of the laser and realize the mutual conversion between linearly polarized light and circularly 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 Figure 1 、 Figure 2 The photoelectric sensor 23 is used to measure the light intensity of the zero-order interference fringe, thereby inferring the magnitude of the magnetostriction 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] Applications of function signal generators and power amplifiers:

[0078] See Figure 1 The function signal generator 16 and power amplifier 17 together form the 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 signals, causing the excitation coil to generate an AC magnetic field of the order of 10 kHz and 5 mT, causing the magnetostrictive material to vibrate at a high frequency.

[0079] Application of digital oscilloscope and temperature controller:

[0080] See 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. By adjusting the temperature controller 20, the temperature of the magnetostrictive material 39 is changed to study the temperature characteristics of the dynamic magnetostriction coefficient.

[0082] Applications of Metal Film Resistors:

[0083] See Figure 1 The metal film resistor 18 is provided 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 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 in operation, 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 enhancing the measurement accuracy of the device.

[0086] Applications of photoelectric sensors:

[0087] See 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 to facilitate 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 Figure 1 、 Figure 2 The photoelectric sensor uses a transimpedance TIA amplifier module 25 to improve the sensor's sensitivity and signal-to-noise ratio. The TIA amplifier circuit is a universal broadband amplifier circuit that takes a current in the nanoamp range and outputs a voltage of several volts, achieving a gain of 100,000 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 vibrations. A silicon photodiode 27 is directly mounted on the input terminal 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 ranging from 400 to 800nm, which meets the requirements for measuring the light intensity of helium-neon lasers. A DC power supply 24 is connected to the power supply port 31 of the photoelectric sensor to power the sensor. The signal is extracted from the SMA interface 28 via a BNC-J / SMA-J male jumper cable 29 and divided into two signals that are fed into different channels of a digital oscilloscope 19. The two signals are respectively DC-coupled and AC-coupled to measure the low-frequency and high-frequency components of 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 appended 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; The four sides of the polarization beam splitter (11) are orthogonally provided with a 1 / 2λ wave plate (7), a first 1 / 4λ wave plate (8), a second 1 / 4λ wave plate (12) and a polarizer (21) along the optical path; 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 polarizer (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 reflective mirror (14); 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). 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 holder (15) further comprises an aluminum holder front end (33), an aluminum holder rear end (34), an outer quartz tube (35) and an inner quartz tube (38); 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, and the two ends of the tubular shape are respectively arranged on the aluminum holder front end (33) and the aluminum holder 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 DC power supply (24).

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