Raman testing apparatus and method for phase change materials

Abstract

This application provides a Raman testing apparatus and method for phase change materials, relating to the field of photonic neuromorphic computing technology. The Raman testing apparatus includes: a laser system for emitting excitation light at a first moment to induce a phase change in the phase change material, and for emitting excitation light at a second moment to excite the phase change material to generate a Raman signal, wherein the intensity of the excitation light is greater than the intensity of the excitation light; and a detection system for acquiring the Raman signal to determine the degree of phase change in the phase change material. The Raman testing apparatus provided in this application can provide real-time feedback of the phase change degree through the Raman signal during the phase change process, achieving in-situ material property detection without affecting laser direct writing.

Description

Technical Field

[0001] This application relates to the field of photonic neuromorphic computing technology, and more specifically, to a Raman testing device and method for phase change materials. Background Technology

[0002] Photonic neuromorphic computing is a technique for processing neuromorphic computational data in the optical domain. It fully leverages the advantages of high-speed photon transmission, low power consumption, and high parallelism while avoiding the additional time and power consumption overhead associated with photoelectric and electro-optical conversions, making it highly valuable for research and application. Within this field, phase-change materials (PCMs), as optical materials with high refractive index contrast and non-volatile properties, can have their refractive index continuously adjusted under optical, electrical, and thermal stimuli, providing a feasible solution for non-volatile photonic neuromorphic computing and becoming a current research hotspot.

[0003] The characteristic of phase change materials (PCMs) lies in their dynamically tunable optical, electrical, and magnetic physical properties. This is because PCMs can undergo changes in their lattice state under external stimuli, typically switching between an amorphous and a crystalline state. These two states possess completely different physical properties, thus providing logically distinguishable contrasting states. When PCMs are subjected to external electrical, optical, or thermal stimuli, their lattice structure can switch between two states: amorphous (completely disordered) and crystalline (completely ordered), exhibiting significant differences in external properties such as refractive index and resistivity. Taking GST as an example, when it is in the amorphous state, its lattice structure is completely disordered, with relatively low refractive index, extinction coefficient, and electrical conductivity. When it is in the crystalline state, its lattice structure is completely ordered, with relatively high refractive index, extinction coefficient, and electrical conductivity. Utilizing the differences between these two states, storage and computing applications can be designed and implemented.

[0004] Laser direct writing is a technique that focuses a laser beam into an extremely small spot to act on photosensitive or thermosensitive thin film materials, causing changes in their properties. It utilizes pulsed light to excite phase change materials, enabling reconfiguration between amorphous and crystalline states. When a crystalline phase change material is excited by a short, high-energy pulse, its internal structure is disrupted, and it transforms into an amorphous state during rapid cooling. When an amorphous phase change material is excited by a long, low-energy pulse, the material melts, and during slow cooling, its lattice rearranges to reform into a crystalline state.

[0005] There are two most common methods for characterizing the phase transition state of phase change materials: one is X-ray diffraction (XRD), which determines the degree of phase transition by examining X-rays of the material. When a crystal sample is irradiated with X-rays, strong diffraction occurs in the crystal planes that satisfy the Bragg equation because the wavelength of the X-rays is on the same order of magnitude as the interatomic spacing. By analyzing the distribution of diffraction intensity, the characteristics of the internal lattice structure of the crystal can be reflected. The other method is to obtain the optical constants under different phase transition states. The optical constants of thin film materials can usually be obtained in two ways: one is to use an elliptic spectrometer to calculate the optical constants by measuring the change in polarization state when polarized light is reflected or transmitted on the thin film; the other is to measure the reflectance and transmittance. If the thickness of the thin film is known, the optical constants can be calculated by fitting the reflection or transmission spectrum.

[0006] However, the above two methods are complex to operate, requiring multiple data processing steps to obtain results, making them difficult to operate and difficult to determine the degree of phase change in a timely manner during the phase change process of phase change materials. Summary of the Invention

[0007] To address at least one of the aforementioned problems, this application proposes a Raman testing apparatus and method for phase change materials.

[0008] According to a first aspect of this application, at least one embodiment of this application provides a Raman testing apparatus for phase change materials, comprising: a laser system for emitting excitation light at a first moment to induce a phase change in the phase change material, and for emitting excitation light at a second moment to excite the phase change material to generate a Raman signal, wherein the intensity of the excitation light is greater than the intensity of the excitation light; and a detection system for acquiring the Raman signal to determine the degree of phase change in the phase change material.

[0009] For example, in some embodiments of this application, the laser system includes: a laser direct writing unit for emitting the excitation light at a first moment and emitting the excitation light at a second moment; a first beam splitter for reflecting the excitation light and the excitation light; and an objective lens for receiving the excitation light and the excitation light and incident them perpendicularly onto the phase change material to cause the phase change material to undergo a phase change and to excite the phase change material to generate a Raman signal.

[0010] For example, in some embodiments of this application, the laser system includes: a laser direct writing unit for emitting the excitation light at a first moment; a laser for emitting the excitation light at a second moment; a laser collimator for modulating the excitation light into parallel light; a second beam splitter for reflecting the parallel light; a first beam splitter for reflecting the excitation light and the parallel light reflected by the second beam splitter; and an objective lens for receiving the excitation light and the parallel light reflected by the first beam splitter, so as to be incident perpendicularly onto the phase change material, causing the phase change material to undergo a phase change and exciting the phase change material to generate a Raman signal, wherein the excitation light and the excitation light coincide on the phase change material.

[0011] For example, in some embodiments of this application, the detection system includes: a filter for filtering the excitation light and the excitation light reflected by the phase change material, so that the Raman signal can pass through; and a spectrometer for acquiring the Raman spectrum of the Raman signal to determine the degree of phase change of the phase change material.

[0012] For example, in some embodiments of this application, the detection system further includes: a first lens for focusing the Raman signal filtered by the filter and projecting it to the spectrometer.

[0013] For example, in some embodiments of this application, the detection system further includes: a spatial filter for detecting the Raman signal focused by the first lens and filtering out optical noise, the spatial filter including: a pinhole aperture; and a second lens for receiving the Raman signal passed through the spatial filter and outputting it to the spectrometer.

[0014] For example, in some embodiments of this application, the detection system further includes: an optical fiber coupler for coupling the Raman signal filtered by the filter and transmitting the Raman signal to the spectrometer.

[0015] For example, in some embodiments of this application, a sample stage is further included, for placing the phase change material and moving it according to a set time so that the excitation light and the excitation beam irradiate different positions of the phase change material.

[0016] For example, in some embodiments of this application, it further includes: a galvanometer system, comprising: an X-axis galvanometer for receiving adjustment commands to change the X-axis position of the excitation light and the excitation beam emitted; a Y-axis galvanometer for receiving adjustment commands to change the Y-axis position of the excitation light and the excitation beam emitted; and an objective lens for receiving the excitation light and the excitation beam after the X-axis and Y-axis positions have been changed, so that they are incident perpendicularly onto the phase change material, causing the excitation light and the excitation beam to irradiate different positions of the phase change material.

[0017] According to a second aspect of this application, at least one embodiment of this application provides a Raman testing method for phase change materials, performed by a Raman testing apparatus as described in any one of the first aspects, the Raman testing method comprising: emitting excitation light at a first moment to induce a phase change in the phase change material; emitting excitation light at a second moment to excite the phase change material to generate a Raman signal; and acquiring the Raman signal to determine the degree of phase change in the phase change material.

[0018] For example, in some embodiments of this application, the method further includes: moving the position of the phase change material, or using a galvanometer system to move the excitation light and the excitation beam, so that the excitation light and the excitation beam irradiate different positions of the phase change material.

[0019] Through the above example embodiments, the Raman testing device and method for phase change materials provided in this application can provide real-time feedback on the phase change degree through Raman signals during the phase change process, realize in-situ material property detection without affecting laser direct writing, detect the phase change degree in real time during the phase change excitation of the phase change material, is simple to operate, provides real-time feedback, and can intuitively provide feedback results through spectral comparison. It is highly operable, a fast and non-destructive material characterization method with high spectral and spatial resolution.

[0020] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description

[0021] The above and other objects, features, and advantages of this application will become more apparent from the detailed description of exemplary embodiments with reference to the accompanying drawings. The drawings described below are merely some embodiments of this application and are not intended to limit the scope of this application.

[0022] Figure 1 A schematic diagram of a Raman testing apparatus for phase change materials is shown in an exemplary embodiment.

[0023] Figure 2 A schematic diagram of the direct writing point of a phase change material sample is shown in an exemplary embodiment;

[0024] Figure 3 Another embodiment of an exemplary Raman testing apparatus is shown;

[0025] Figure 4 Another embodiment of an exemplary Raman testing apparatus is shown;

[0026] Figure 5 Another embodiment of an exemplary Raman testing apparatus is shown;

[0027] Figure 6 A schematic diagram illustrating a Raman testing method of an exemplary embodiment is shown;

[0028] Figure 7 A schematic diagram showing the timing of the output excitation light and the excitation light of an exemplary Raman testing apparatus is provided.

[0029] Figure 8 A flowchart illustrating a phase transition testing process of an exemplary embodiment is shown. Detailed Implementation

[0030] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this application will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted.

[0031] The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a full understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced without one or more of these specific details, or other methods, components, materials, devices, etc. In these cases, well-known structures, methods, devices, implementations, materials, or operations will not be shown or described in detail.

[0032] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0033] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0034] Those skilled in the art will understand that the accompanying drawings are merely schematic diagrams of exemplary embodiments, and the modules or processes in the drawings are not necessarily necessary for implementing this application, and therefore cannot be used to limit the scope of protection of this application.

[0035] Figure 1A schematic diagram of a Raman testing apparatus for phase change materials is shown in an exemplary embodiment.

[0036] like Figure 1 As shown, the Raman testing device includes a laser system 10 and a detection system 20.

[0037] The laser system 10 emits excitation light at a first moment to induce a phase transition in the phase change material, and emits excitation light at a second moment to excite the phase change material to generate a Raman signal. The intensity of the excitation light is much greater than that of the excitation light.

[0038] The detection system 20 is used to acquire Raman signals to determine the degree of phase change of the phase change material.

[0039] According to an example embodiment, the laser system 10 includes a laser direct writing unit 101, a first beam splitter 102, and an objective lens 103.

[0040] The laser direct writing unit 101 is used to emit excitation light at a first moment and excitation light at a second moment. The first beam splitter 102 is used to reflect the excitation light and excitation light. The objective lens 103 is used to receive the excitation light and excitation light, so as to incident perpendicularly on the phase change material, so as to cause the phase change material to undergo a phase change and to excite the phase change material to generate a Raman signal.

[0041] According to some embodiments, the first beam splitter 102 is used to realize the function of splitting the beam into reflection and transmission, including but not limited to beam splitters of various ratios, polarization and non-polarization, such as beam splitters, half-reflective mirrors, dichroic mirrors, Wollaston prisms and so on.

[0042] According to some embodiments, objective lens 103 is selected as an objective lens with an infinity conjugate design, that is, after the light reflected by the sample enters objective lens 103, it does not converge but remains a parallel beam, which allows the required optical elements to be inserted arbitrarily on the detection system side.

[0043] According to some embodiments, the objective lens 103 can also be a field lens. This application only uses this as an example, but is not limited thereto.

[0044] The detection system 20 includes a filter 201 and a spectrometer 202.

[0045] The filter 201 is used to filter the excitation light and excitation light reflected by the phase change material, allowing the Raman signal to pass through. The spectrometer 202 is used to acquire the Raman spectrum of the Raman signal to determine the degree of phase change of the phase change material.

[0046] Raman spectroscopy is a rapid, non-destructive method with high spatiotemporal resolution for characterizing and probing material properties. It can provide information on material structure, electronic structure, lattice vibrations, etc., and can be used for component identification, microstructure determination, phase transition research, parameter measurement, selective imaging, etc., and has been widely applied in physics, chemistry, biology, medicine, materials science, microelectronics, and other disciplines. The paper "A New Family of Ultralow Loss Reversible Phase-Change Materials for Photonic Integrated Circuits: Sb₂S₃ and Sb₂Se₃" demonstrates that the positions and full width at half maximum (FWHM) of Raman peaks in phase change materials differ significantly in different phase transition states, and the phase transition state can be determined through Raman spectroscopy. This invention provides a method for laser-direct-writing in-situ Raman testing and characterization of phase change materials, which allows for real-time feedback of the phase transition degree through Raman light during the phase transition process.

[0047] According to some embodiments, the filter 201 is used to achieve transmission in a specific wavelength band, and different types of components can be selected according to the actual application.

[0048] In Embodiment 1, the detection system 20 further includes a first lens 203. The first lens 203 is used to focus the Raman signal filtered by the filter 201 and output it to the spectrometer 202.

[0049] In the second embodiment, the detection system 20 further includes: a first lens 203, a spatial filter 204, and a second lens 205.

[0050] The first lens 203 is used to focus the Raman signal filtered by the focusing filter 201. The spatial filter 204 is used to detect the Raman signal focused by the first lens 203 and filter out optical noise. The second lens 205 is used to receive the Raman signal after passing through the spatial filter 204 and output it to the spectrometer 202.

[0051] A spatial filter is placed in front of the spectrometer. This spatial filter is conjugate to the laser focus of the Raman excitation light on the sample. Therefore, light from the laser focus can be detected by the detector through the pinhole of the spatial filter 204, while scattered light from other locations is blocked by the pinhole. This effectively suppresses background light noise, improves the signal-to-noise ratio, and is beneficial for detecting relatively weak Raman signals.

[0052] According to some embodiments, the spatial filter 204 can be a pinhole aperture. This application uses this as an example only, but is not limited thereto.

[0053] In embodiment three, the detection system 20 further includes an optical fiber coupler. The optical fiber coupler is used to couple the Raman signal filtered by the filter 201 and transmit the Raman signal to the spectrometer 202.

[0054] According to an example embodiment, the Raman testing apparatus further includes a sample stage 30.

[0055] The sample stage 30 is used to place the phase change material and moves according to a set time so that the excitation light and the excitation light irradiate different positions of the phase change material.

[0056] The direct-write pattern of phase change materials consists of a lattice, such as... Figure 2 As shown, after the excitation light finishes illuminating the direct writing point on the sample, the Raman excitation light begins illuminating that point. The detection system collects the Raman signal, which is then sent to the spectrometer to obtain Raman spectral information, thereby determining the degree of phase transition at that writing point. Furthermore, this result of the phase transition degree can be fed back to the laser system for parameter adjustment.

[0057] According to an example embodiment, the laser system 10 includes a galvanometer system 107, such as Figure 3 As shown.

[0058] The galvanometer system 107 includes: an X-axis galvanometer 108 and a Y-axis galvanometer 109, such as Figure 4 As shown.

[0059] X-axis galvanometer 108 is used to receive adjustment commands to change the X-axis position of the emitted excitation light and excitation beam. Y-axis galvanometer 109 is used to receive adjustment commands to change the Y-axis position of the emitted excitation light and excitation beam. Objective lens 103 is used to receive the excitation light and excitation beam after the X-axis and Y-axis positions have been changed, so that they are incident perpendicularly onto the phase change material, causing the excitation light and excitation beam to irradiate different positions of the phase change material.

[0060] Figure 5 Another embodiment of an exemplary Raman testing apparatus is shown.

[0061] Figure 5 Raman testing device and Figure 1 The Raman testing devices are basically similar in structure, with the only difference being that... Figure 5 The laser system of the Raman testing apparatus shown also includes: laser 104.

[0062] According to the example embodiment, the laser direct writing unit 101 is used to emit excitation light at a first moment. The laser 104 is used to emit excitation light at a second moment. The excitation light and the excitation light coincide on the phase change material. Furthermore, the intensity of the excitation light is much greater than the intensity of the excitation light.

[0063] According to some embodiments, since two light sources are incident on the sample through one objective lens, based on the theoretical Rayleigh resolution of 0.61*λ / NA, it is known that the size of the focused spot of the objective lens is related to the incident wavelength. Therefore, a shorter wavelength light can be selected as the Raman excitation light, thereby ensuring that the excitation region of the Raman excitation light is smaller than the excitation region of the laser direct writing, that is, the Raman signal comes entirely from the phase transition region.

[0064] Figure 5 The laser system of the Raman testing apparatus shown also includes a laser collimator 105 and a second beam splitter 106.

[0065] The laser collimator 105 is used to modulate the excitation light into parallel light. The second beam splitter 106 is used to reflect the parallel light back to the first beam splitter 102 so that the objective lens 103 can receive it and incident perpendicularly onto the phase change material.

[0066] This application also proposes a Raman testing method for phase change materials, performed by the Raman testing apparatus as described above.

[0067] like Figure 6 As shown, the Raman testing method includes: emitting excitation light at a first moment to induce a phase change in the phase change material; emitting excitation light at a second moment to excite the phase change material to generate a Raman signal; and acquiring the Raman signal to determine the degree of phase change in the phase change material.

[0068] Furthermore, after completing the direct writing excitation and Raman spectroscopy test at one direct writing point, the position of the phase change material is moved, or the excitation light and excitation beam are moved, so that the excitation light and excitation beam irradiate the next direct writing point of the phase change material, and the above method is repeated.

[0069] According to some embodiments, the following can be used: Figure 4 The galvanometer system shown can be used to move the excitation beam and the excitation beam, but other methods can also be used to move the excitation beam and the excitation beam.

[0070] This application provides a Raman testing device and method for phase change materials, which can provide real-time feedback on the phase change degree through Raman signals during the phase change process. It enables in-situ material property detection without affecting laser direct writing. It can detect the phase change degree in real time during the phase change excitation of the phase change material. It is simple to operate, provides real-time feedback, and can intuitively provide feedback results through spectral comparison. It is highly operable, a fast and non-destructive material characterization method with high spectral and spatial resolution.

[0071] like Figure 7 As shown, at times t1-t2, the excitation light is emitted with an intensity of I1. At times t2-t3, the excitation light is emitted with an intensity of I2. I1 is much greater than I2. After completing the direct writing excitation and Raman spectroscopy test at one direct writing point, the sample stage is moved to repeat the above operation for the next direct writing point.

[0072] The samples consisted of two 23 nm thick Sb₂Se₃ phase transition material thin films on SiO₂ substrates. The initial states of the samples were: sample A was amorphous, and sample B was crystalline. The Raman spectra of both samples were measured at this stage, with the Raman excitation light intensity set to 190 μW, yielding Raman spectra A and B, respectively, for comparison of the subsequent phase transition degree. The phase transition between crystalline and amorphous states was controlled using a laser system. The laser source was a tunable continuous-wave laser with a wavelength of 638 nm; in this application, a 532 nm continuous-wave laser was selected as the excitation source. A 640 nm long-pass filter was used.

[0073] Figure 8 The specific operational procedure of the Raman test method is as follows: Figure 5 Taking the Raman testing device shown as an example: the operation procedures for sample A and sample B are similar.

[0074] For sample A:

[0075] Set the pulse mode of the laser system light source to 50ms and 19mW, and adjust the system focus so that the light spot of the 532nm laser on the sample coincides with the light spot of the 638nm laser on the sample.

[0076] After turning on the laser system and outputting an excitation light pulse, turn on the Raman excitation light with an intensity of 190uW and test the Raman spectrum to complete the test of one laser direct writing point. Continue testing according to the laser system. Perform a Raman test after each laser direct writing pulse and compare the obtained Raman spectrum with Raman spectrum A to confirm that each laser direct writing point is crystalline.

[0077] For sample B:

[0078] Set the laser system's light source pulse mode to 400ns and 35mW, and adjust the system focus so that the 532nm laser spot on the sample coincides with the 638nm laser spot on the sample.

[0079] After turning on the laser system and outputting an excitation pulse, the Raman excitation light is turned on with an intensity of 190 μW. The Raman spectrum is then tested to complete the test of one laser direct writing point. Subsequent tests are continued based on the laser system. A Raman test is performed after each laser direct writing pulse. The Raman spectrum obtained is compared with Raman spectrum B to confirm that each point of laser direct writing is amorphous.

[0080] According to some embodiments, the switching control of the laser system in this application for the purpose of controlling the light entering the objective lens includes, but is not limited to, controlling the laser switch or an external optical switch.

[0081] It should be clearly understood that this application describes how specific examples are formed and used, but this application is not limited to any details of these examples. Rather, based on the teachings of the disclosure of this application, these principles can be applied to many other embodiments.

[0082] Furthermore, it should be noted that the above figures are merely illustrative representations of the processes included in the method according to exemplary embodiments of this application, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0083] Exemplary embodiments of this application have been specifically shown and described above. It should be understood that this application is not limited to the detailed structures, arrangements, or implementation methods described herein; rather, this application is intended to cover various modifications and equivalent arrangements that fall within the objectives and scope of the appended claims.

Claims

1. A Raman testing device for phase change material, characterized by, The laser system comprises: a laser direct writing unit for emitting the excitation light at the first time and emitting the excitation light at the second time; or the laser direct writing unit is used for emitting the excitation light at the first time; a laser for emitting the excitation light at the second time; a detection system for acquiring the Raman signal to determine the phase change degree of the phase change material, and for feeding back the result of the phase change degree to the laser system to make the laser system adjust parameters. The laser system further comprises:

2. The Raman testing apparatus of claim 1, wherein, a first beam splitter for reflecting the excitation light and the excitation light; an objective lens for receiving the excitation light and the excitation light to be perpendicular to the phase change material to make the phase change material produce phase change and excite the phase change material to produce Raman signal. The laser system further comprises:

3. The Raman testing apparatus of claim 1, wherein, a laser collimator for modulating the excitation light into parallel light; a second beam splitter for reflecting the parallel light; a first beam splitter for reflecting the excitation light and the parallel light reflected by the second beam splitter; an objective lens for receiving the excitation light and the parallel light reflected by the first beam splitter to be perpendicular to the phase change material to make the phase change material produce phase change and excite the phase change material to produce Raman signal, wherein the excitation light and the excitation light coincide on the phase change material. The detection system comprises:

4. The Raman testing apparatus of claim 1, wherein, a filter for filtering the excitation light and the excitation light reflected by the phase change material so that the Raman signal can pass through; a spectrometer for acquiring the Raman spectrum of the Raman signal to determine the phase change degree of the phase change material. The detection system further comprises:

5. The Raman testing apparatus of claim 4, wherein, a first lens for focusing the Raman signal filtered by the filter and emitting to the spectrometer. The detection system further comprises:

6. The Raman testing apparatus of claim 5, wherein, a spatial filter for detecting the Raman signal focused by the first lens and filtering out optical noise, the spatial filter comprising: a pinhole diaphragm; a second lens for receiving the Raman signal passing through the spatial filter and emitting to the spectrometer.

7. The Raman testing apparatus of claim 4, wherein, The detection system further comprises: an optical fiber coupler for coupling the Raman signal filtered by the filter and transmitting the Raman signal to the spectrometer.

8. The Raman testing apparatus of claim 1, wherein, Further comprising: a sample stage for placing the phase change material and moving according to the set time to make the excitation light and the excitation light irradiate different positions of the phase change material.

9. The Raman testing apparatus of claim 2, wherein, The laser system further comprises: a galvanometer system comprising: an X-axis galvanometer for receiving adjustment instructions to change the position of the X-axis of the emission of the excitation light and the excitation light; a Y-axis galvanometer for receiving adjustment instructions to change the position of the Y-axis of the emission of the excitation light and the excitation light; The objective lens is used to receive the excitation light and the excitation light after the X-axis and Y-axis positions are changed, to make the excitation light and the excitation light perpendicularly incident on the phase change material, so that the excitation light and the excitation light irradiate different positions of the phase change material.

10. A method for Raman testing of a phase change material, characterized by, The Raman testing method is executed by the Raman testing device as claimed in any one of claims 1-9, and the Raman testing method comprises: Emitting excitation light at a first time to make the phase change material produce phase change; Emitting excitation light at a second time to excite the phase change material to produce Raman signal; Acquiring the Raman signal to determine the phase change degree of the phase change material.

11. The Raman testing method of claim 10, wherein, Further comprising: Moving the position of the phase change material, or moving the excitation light and the excitation light by using a galvanometer system, so that the excitation light and the excitation light irradiate different positions of the phase change material.

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