Laser differential confocal raman spectrum topography-vibration-stress synchronous measurement method and device

Abstract

This invention relates to a method and apparatus for simultaneous measurement of morphology, vibration, and stress using laser differential confocal Raman spectroscopy, belonging to the field of precision photoelectric measurement and microscopic spectral imaging. The apparatus includes a light source system, a beam splitter, an objective lens driver, a measuring objective lens, an XY scanning stage, filters, a Raman spectroscopy detection system, a differential confocal detection system, and a measurement and control system. This invention combines differential confocal detection with Raman spectroscopy detection, utilizing the differential confocal system to achieve morphology measurement and vibration demodulation. Based on this, it achieves focus closed-loop locking. The Raman spectroscopy system, in the locked state, acquires high signal-to-noise ratio spectra, eliminating spatial positioning errors and solving defocusing problems during dynamic measurements. This enables in-situ, synchronous, and high-precision measurement of the morphology, vibration, and stress of micro / nano devices. This invention offers advantages such as in-situ fusion, dynamic tracking, and high signal-to-noise ratio, and is applicable to fields such as microelectromechanical systems (MEMS), nanoelectromechanical systems (NMEMS) testing, and precision instrument manufacturing.

Description

Technical Field

[0001] This invention relates to a method and apparatus for simultaneous measurement of morphology, vibration and stress in laser differential confocal Raman spectroscopy, belonging to the field of precision optoelectronic measurement and microscopic spectral imaging technology. Background Technology

[0002] As microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS) evolve towards miniaturization and higher frequencies, the evaluation of their overall performance is no longer limited to the measurement of a single parameter. For example, in the failure analysis of microresonators, geometric processing errors (morphology) may cause resonant frequency drift (vibration), which in turn leads to localized residual stress concentration (stress). Therefore, simultaneously acquiring information from the three dimensions of morphology, vibration, and stress is crucial for the reliability analysis of devices.

[0003] In existing technologies, the above parameters are typically measured using discrete instruments: a white light interferometer or confocal microscope is used to measure the three-dimensional morphology; a laser Doppler vibrometer (LDV) is used to measure vibration characteristics; and a micro Raman spectrometer is used to measure stress distribution. However, this "discrete measurement" approach has the following three main technical bottlenecks:

[0004] 1) Non-in-situ error in spatial positioning: When transferring micron / nanoscale devices between different instruments, it is difficult to ensure the spatial correspondence of measurement points. This results in the inability to accurately register morphology, vibration, and stress data in space.

[0005] 2) Defocusing problem during dynamic measurement: Traditional Raman spectrometers lack axial focus tracking capability with high-frequency response. When the device under test is vibrating, the device surface will frequently deviate from the depth of focus range of the objective lens, causing drastic fluctuations in the Raman spectral signal intensity, making it impossible to obtain accurate stress inversion results.

[0006] 3) The contradiction between signal separation and signal-to-noise ratio: When trying to integrate multiple measurement techniques into the same optical path, the strong Rayleigh scattering light used for topography measurement often overwhelms the weak Raman spectral scattering light used for stress measurement, and it is difficult to achieve high-precision beam separation without losing spectral information. Summary of the Invention

[0007] To overcome the shortcomings of existing technologies, such as spatial mismatch, dynamic measurement defocusing, and crosstalk between multiple optical paths, the present invention aims to provide a method and device for synchronous measurement of morphology, vibration, and stress using laser differential confocal Raman spectroscopy. This method combines differential confocal microscopy with micro Raman spectroscopy, utilizing differential confocal Rayleigh scattering signals to acquire three-dimensional morphology and high-frequency vibration information of micro-regions, and using inelastic scattering signals from Raman spectroscopy to acquire local stress distribution information, thereby achieving in-situ synchronous measurement of multiple physical fields in micro / nano devices. This invention offers advantages such as in-situ fusion, dynamic tracking, and high signal-to-noise ratio, and is applicable to fields such as microelectromechanical systems (MEMS), nanoelectromechanical systems (NEMS) detection, and precision instrument manufacturing.

[0008] The objective of this invention is achieved through the following technical solution.

[0009] The laser differential confocal Raman spectroscopy method for simultaneous measurement of morphology, vibration, and stress, disclosed in this invention, is based on a shared optical path architecture. It utilizes a differential confocal detection system to construct a morphology scanning and vibration demodulation benchmark, and employs a Raman spectroscopy acquisition system to invert stress data, thereby achieving a holographic characterization of the geometric, dynamic, and mechanical properties of the device under test. Specifically, it includes the following steps:

[0010] Step 1: Control the light source system to emit a highly coherent continuous probe beam, which is expanded and collimated before entering the measuring objective lens through a beam splitter and focusing on the surface of the device under test.

[0011] Step 2: Control the XY scanning stage to move the device under test to the test point, collect the backscattered light reflected back from the device under test, return through the original optical path and pass through the beam splitter, and use a filter to separate the optical path into reflected elastic Rayleigh scattering light and transmitted inelastic Raman spectral scattering light.

[0012] Step 3: Drive the measuring objective lens to perform a linear scan along the optical axis, use the differential confocal detection system to simultaneously acquire the light intensity signals before and after focus, and perform normalized differential calculations to construct the differential confocal axial intensity response curve.

[0013] Step 4: Fit the linear region of the differential confocal axial strength response curve, calculate the linear zero-crossing point as the absolute morphological height of the device under test, and establish a sensing model of differential voltage and axial displacement.

[0014] Step 5: Based on the absolute topographic height calculated in Step 4, drive the measurement objective lens to lock in the absolute focal plane position of the device under test, turn on the time domain measurement mode, and collect the light intensity fluctuation signal output by the differential confocal detection system.

[0015] Step 6: Perform frequency domain transformation on the light intensity fluctuation signal, and combine it with the sensing model to convert the voltage amplitude into physical displacement, and demodulate the micro-amplitude vibration frequency and amplitude of the measured point.

[0016] Step 7: While keeping the measuring objective lens in focus-locked state, synchronously trigger the Raman spectroscopy acquisition system, filter out Rayleigh scattering light, and then acquire high signal-to-noise ratio Raman spectral data of the measured point.

[0017] Step 8: Fit the characteristic peaks of the Raman spectrum, extract the Raman spectral frequency shift, and calculate the local stress value by combining the Raman spectral stress coefficient of the material.

[0018] Step 9: Control the XY scanning stage to scan the area to be tested point by point along the predetermined path. Repeat steps 3 to 8 for each pixel point to simultaneously acquire the topography, height, vibration parameters and stress value of that point.

[0019] Step 10: Perform matrix fusion on the acquired three-dimensional topography data, vibration mode data, and stress distribution data to generate a multi-parameter in-situ fused image containing three-dimensional geometric information, vibration information, and stress information.

[0020] Furthermore, the linear scan range in step three covers the entire linear interval of the differential confocal response curve.

[0021] Furthermore, the closed-loop locking in step five is achieved by adjusting the drive voltage of the objective lens driver through a PID control algorithm to maintain the differential signal at zero.

[0022] Furthermore, the frequency domain transformation in step six employs Fast Fourier Transform (FFT) to extract the resonant frequency of the device under test.

[0023] This invention discloses a laser differential confocal Raman spectroscopy morphology-vibration-stress synchronous measurement device, used to realize the aforementioned laser differential confocal Raman spectroscopy morphology-vibration-stress synchronous measurement method. The device includes a light source system, a beam splitter, an objective lens driver, a measuring objective lens, a device under test, an XY scanning stage, a filter, a Raman spectroscopy detection system, a differential confocal detection system, and a measurement and control system. The light source system generates a highly coherent detection beam; the objective lens driver drives the measuring objective lens to perform axial scanning and locking; the filter achieves spectral separation of Rayleigh scattered light and Raman spectral scattered light; the differential confocal detection system receives reflected Rayleigh scattered light and generates a differential signal; the Raman spectroscopy detection system receives transmitted Raman spectral scattered light and acquires the spectrum; the measurement and control system drives the hardware, performs data acquisition, signal demodulation, and multi-parameter fusion processing.

[0024] The light beam emitted by the light source system is converged onto the device under test (DUT) by a measuring objective driven by an objective lens driver. Backscattered light reflected from the DUT is collected by the measuring objective and returns along the original optical path, passing through a beam splitter and reaching a filter. The filter separates the optical path, reflecting Rayleigh scattered light and transmitting Raman scattered light. The transmitted Raman scattered light is focused by a Raman spectral converging lens, passes through a Raman spectral pinhole, and enters the Raman spectrometer for stress spectral detection. The reflected Rayleigh scattered light enters a differential beam splitter and is split into two paths: one path is focused by a front focal converging lens, passes through a front focal pinhole, and is received by a front focal detector; the other path is focused by a rear focal converging lens, passes through a rear focal pinhole, and is received by a rear focal detector for differential confocal detection.

[0025] Preferably, the light source system includes a laser and a beam expander for generating a collimated, highly coherent probe beam.

[0026] Preferably, the Raman spectroscopy detection system includes a Raman spectroscopy focusing mirror, a Raman spectroscopy pinhole, and a Raman spectrometer; the Raman spectroscopy focusing mirror is used to focus the Raman spectral scattered light onto the Raman spectroscopy pinhole, and the Raman spectroscopy pinhole is used to filter out defocused stray light to achieve high signal-to-noise ratio detection.

[0027] Preferably, the differential confocal detection system includes a differential beam splitter, a front focal converging lens, a front focal pinhole, a front focal detector, a reflector, a rear focal converging lens, a rear focal pinhole, and a rear focal detector; the front focal pinhole is located in front of the focal plane of the front focal converging lens, and the rear focal pinhole is located behind the focal plane of the rear focal converging lens.

[0028] Preferably, the filter is a notch filter, used to achieve efficient separation of Raman spectral signals and Rayleigh signals.

[0029] Preferably, the objective actuator includes a piezoelectric ceramic micro-displacement platform for achieving nanoscale axial scanning and locking.

[0030] Beneficial effects:

[0031] 1. The laser differential confocal Raman spectroscopy morphology-vibration-stress synchronous measurement method and device disclosed in this invention combines differential confocal detection with Raman spectroscopy detection. It uses a differential confocal system to realize morphology measurement and vibration demodulation, and uses this as a reference to realize focus closed-loop locking. It uses the Raman spectroscopy system to obtain high signal-to-noise ratio spectrum in the locked state, eliminates spatial positioning error, solves the defocusing problem during dynamic measurement, and realizes in-situ synchronous high-precision measurement of morphology, vibration and stress of micro and nano devices.

[0032] 2. The laser differential confocal Raman spectroscopy method and apparatus for synchronous measurement of morphology, vibration, and stress disclosed in this invention are based on a shared optical path architecture. Utilizing the high axial sensitivity and linear response characteristics of the differential confocal detection system, a measurement benchmark for morphology scanning, vibration demodulation, and focus tracking is constructed. Furthermore, common-path Raman spectroscopy detection is integrated, and stress data is inverted using the Raman spectroscopy acquisition system, thereby achieving a holographic characterization of the geometric, dynamic, and mechanical properties of the device under test. This invention combines differential confocal detection technology with micro-Raman spectroscopy technology. It utilizes the linear mapping characteristics between signal intensity and axial position in the linear interval of the differential confocal axial response curve to construct a sensing model and perform absolute focal plane closed-loop locking. Combined with fast Fourier transform to extract vibration parameters and Raman characteristic peak fitting to invert and calculate micro-region stress, it achieves in-situ synchronous extraction of the geometric morphology, vibration characteristics, and stress information of the device under test. With the XY scanning stage for point-by-point scanning and data matrix fusion, a multi-parameter in-situ high-resolution fused image can be generated. This invention enables simultaneous measurement of the three-dimensional geometry, high-frequency dynamic vibration, and dynamic stress distribution of micro / nano devices without moving the device under test.

[0033] 3. The laser differential confocal Raman spectroscopy morphology-vibration-stress synchronous measurement method and apparatus disclosed in this invention uses a Raman spectroscopy converging lens to focus the scattered Raman spectral light onto a Raman spectral pinhole. This pinhole filters out defocused stray light, achieving high signal-to-noise ratio detection. The filter is a notch filter, used to achieve efficient separation of the Raman spectral signal and the Rayleigh signal. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of a laser differential confocal Raman spectroscopy morphology-vibration-stress synchronous measurement method according to the present invention;

[0035] Figure 2 This is a schematic diagram of a laser differential confocal Raman spectroscopy morphology-vibration-stress synchronous measurement device according to the present invention;

[0036] Figure 3 This is a schematic diagram of the demodulation of a synchronous measurement signal of laser differential confocal Raman spectroscopy morphology-vibration-stress.

[0037] The components are as follows: 1-Laser, 2-Beam expander, 3-Light source system, 4-Beam splitter; 5-Objective driver, 6-Measuring objective, 7-Device under test, 8-XY scanning stage, 9-Filter; 10-Raman spectroscopy converging mirror; 11-Raman spectroscopy pinhole, 12-Raman spectrometer, 13-Raman spectroscopy detection system; 14-Differential beam splitter, 15-Front focal converging mirror, 16-Front focal pinhole; 17-Front focal detector; 18-Reflecting mirror, 19-Back focal converging mirror; 20-Back focal pinhole; 21-Back focal detector; 22-Differential confocal detection system; 23-Measurement and control system. Detailed Implementation

[0038] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation steps.

[0039] Example

[0040] like Figure 2 As shown, the laser differential confocal Raman spectroscopy morphology-vibration-stress synchronous measurement device disclosed in this invention mainly consists of a light source system 3, a main optical path assembly, a Raman spectroscopy detection system 13, a differential confocal detection system 22, and a measurement and control system 23.

[0041] The light source system 3 consists of a laser 1 and a beam expander 2. The linearly polarized beam emitted by the laser 1 is collimated and expanded by the beam expander 2 before being incident on the beam splitter 4. The beam splitter 4 reflects the beam into the measurement optical path, and after passing through the measurement objective lens 6 driven by the objective lens driver 5 (e.g., a piezoelectric ceramic driver), it is converged onto the surface of the device under test 7, which is mounted on the XY scanning stage 8. The backscattered light signal reflected from the surface of the device under test 7 (including Rayleigh scattering and Raman spectral scattering) is collected by the measurement objective lens 6, passes through the beam splitter 4, and reaches the filter 9. Here, the filter 9 is a notch filter, used to achieve high-precision spectral separation.

[0042] Raman spectroscopy detection system: The Raman spectral scattered light transmitted through filter 9 enters the Raman spectroscopy detection system 13. The beam is focused sequentially by the Raman spectroscopy converging lens 10, passes through the Raman spectroscopy pinhole 11, and finally enters the Raman spectrometer 12. The Raman spectroscopy pinhole 11 is located at the focal point of the Raman spectroscopy converging lens 10 and is used to filter out defocused stray light to achieve confocal Raman spectroscopy detection.

[0043] Differential confocal detection system: Rayleigh scattered light reflected by filter 9 enters the differential confocal detection system 22. The beam first enters the differential beam splitter 14 and is split into two beams of equal intensity. The reflected beam is focused by the front focal converging lens 15, passes through the front focal pinhole 16 located in front of the focal point, and is received by the front focal detector 17; the transmitted beam is reflected by the differential beam splitter 14, the light path is deflected by the reflecting mirror 18, focused by the rear focal converging lens 19, passes through the rear focal pinhole 20 located behind the focal point, and is received by the rear focal detector 21.

[0044] The measurement and control system 23 is electrically connected to the laser 1, objective lens driver 5, XY scanning stage 8, Raman spectrometer 12, front focus detector 17 and back focus detector 21 respectively, to realize synchronous triggering, data acquisition, calculation and processing and closed-loop control.

[0045] This embodiment discloses a method for simultaneous measurement of morphology, vibration, and stress in laser differential confocal Raman spectroscopy. The specific implementation steps are as follows:

[0046] Step 1: Turn on laser 1 to output excitation light with a stable wavelength. Start the measurement and control system 23 and send a reset command to the objective lens driver 5. After the beam is expanded by the beam expander 2, it fills the entrance pupil of the measuring objective lens 6, ensuring optimal optical resolution.

[0047] Step 2: The measurement and control system 23 sends a pulse signal to drive the XY scanning stage 8, which moves the device under test 7 to the test point. The backscattered light collected by the measuring objective lens 6 is separated when it passes through the filter 9: the elastic Rayleigh scattered light with unchanged wavelength is reflected into the differential confocal detection system 22, while the inelastic Raman spectral scattered light with a frequency shifted wavelength is transmitted into the Raman spectral detection system 13.

[0048] Step 3: The measurement and control system 23 outputs a triangular wave voltage to control the objective lens driver 5, driving the measuring objective lens 6 to perform a linear scan along the optical axis (Z-axis) (e.g., a stroke of 10 μm). During this process, the measurement and control system 23 simultaneously acquires the light intensity signal from the front focus detector 17. and the light intensity signal of the back focus detector 21 And calculate the normalized differential signal.

[0049]

[0050] Step Four: As Figure 3 As shown, the measurement and control system has 23 pairs of... Fit the curve to the linear region and extract the linear sensitivity (slope). and zero-crossing position Because the differential confocal zero-crossing point precisely corresponds to the focal point, the measurement and control system records 23. driving voltage at time The absolute morphological height of the device under test 7 is calculated based on the piezoelectric constant of the objective lens actuator 5. .

[0051] Step 5: The measurement and control system 23 switches to closed-loop servo mode, transmitting the real-time acquired differential signal. As an error input, the voltage output to the objective lens driver 5 is adjusted via a PID algorithm, forcibly locking the measuring objective lens 6 to the specified position. The absolute focal plane position is determined. At this time, the time-domain measurement mode is activated, and the measurement and control system 23 reads the light intensity fluctuation signals output by the front focal detector 17 and the rear focal detector 21 at a high sampling rate (e.g., 2MHz). .

[0052] Step Six: If the device under test 7 experiences slight vibrations, it will cause fluctuations in light intensity. The measurement and control system 23 uses the sensing model established in Step Four to convert the voltage fluctuations into physical displacement. Vibration data such as the main peak frequency and amplitude of the measured point are obtained by demodulation using Fast Fourier Transform. .

[0053] Step 7: With the objective lens driver 5 in focus-locked state (where the excitation spot energy is most concentrated and the signal-to-noise ratio is highest), the measurement and control system 23 sends a trigger signal to the Raman spectrometer 12. The Raman spectroscopy detection system 13 acquires high signal-to-noise ratio Raman spectral data after Rayleigh light has been filtered out by the filter 9.

[0054] Step 8: The measurement and control system 23 performs Lorentz or Gaussian fitting on the spectral data to extract the center wavenumber of the Raman spectral characteristic peaks. Based on the preset material Raman spectral stress coefficient Inverse calculation of the stress at this point :

[0055]

[0056] in This is the calibration wavenumber under stress-free conditions.

[0057] Step 9: The measurement and control system 23 drives the XY scanning stage 8 to move to the next pixel point, repeating steps 3 to 8, and simultaneously acquiring the topography height, vibration parameters and stress value of that point.

[0058] Step 10: After scanning the predetermined area, the measurement and control system 23 will collect the topographic data of all coordinate points. Vibration data and stress data Matrix fusion is performed to generate a multi-parameter in-situ fused image containing three-dimensional geometric information, vibration information, and stress information.

[0059] The specific embodiments of the present invention have been described above with reference to the accompanying drawings. However, these descriptions should not be construed as limiting the scope of the present invention. The scope of protection of the present invention is defined by the appended claims. Any modifications based on the claims of the present invention are within the scope of protection of the present invention.

Claims

1. A laser differential confocal Raman spectroscopy topography-vibration-stress synchronous measurement method, characterized in that: By utilizing the linear mapping characteristics between signal intensity and axial position in the linear interval of the differential confocal axial response curve, the device under test is axially scanned and focused, and Raman spectroscopy detection optical path is synchronously fused based on this. By separating and synchronously processing Rayleigh scattering light and Raman spectral scattering light, geometric morphology, vibration characteristics and stress information are extracted simultaneously in a single measurement, realizing in-situ synchronous high-resolution imaging of multi-physics fields of micro and nano devices.

2. The laser differential confocal Raman spectrography topography-vibration-stress synchronous measurement method according to claim 1, characterized in that: Includes the following steps, Step 1: The light source system (3) generates a highly coherent probe beam. After the probe beam is collimated by the beam expander (2), it is reflected by the beam splitter (4) and enters the measuring objective lens (6) to be focused on the surface of the device under test (7). Step 2: The measurement and control system (23) controls the XY scanning stage (8) to drive the device under test (7) to locate the measurement point along the XY direction. The reflected light from the device under test (7) is collected by the measuring objective lens (6) and returns along the original optical path. After passing through the beam splitter (4), it reaches the filter (9). The filter (9) separates the optical path. The transmitted light enters the Raman spectroscopy detection system (13), and the reflected light enters the differential confocal detection system (22). Step 3: The measurement and control system (23) controls the objective lens driver (5) to drive the measuring objective lens (6) to perform linear axial scanning along the Z direction, collect the normalized differential signal output by the differential confocal detection system (22), and construct the differential confocal axial intensity response curve of the current scanning point; Step 4: Perform linear fitting on the linear region of the differential confocal axial strength response curve, establish a sensing model of differential voltage and axial displacement, calculate the zero-crossing position based on the model, and determine the absolute morphological height of the device under test (7). Step 5: Based on the topographic height information determined in Step 4, the objective lens driver (5) is driven by the measurement and control system (23) to perform closed-loop feedback, and the measuring objective lens (6) is locked at the absolute focal plane position. The time domain measurement mode is turned on, and the light intensity fluctuation signal output by the differential confocal detection system (22) is collected. Step 6: Perform frequency domain transformation on the light intensity fluctuation signal described in Step 5, and use the sensing model established in Step 4 to convert the voltage amplitude into physical displacement, and demodulate the vibration frequency and amplitude of the measured point. Step 7: While maintaining focus lock, synchronously trigger the Raman spectroscopy detection system (13) to acquire Raman spectral data after filtering out Rayleigh scattering light; Step 8: Fit the Raman spectral characteristic peaks described in Step 7, extract the Raman spectral frequency shift, and calculate the stress value by combining the Raman spectral stress coefficient of the material. Step 9: The measurement and control system (23) controls the XY scanning stage (8) to drive the device under test (7) to scan and process the area under test along the XY direction according to the scanning path input by the user in steps 3 to 8, and obtain the geometric parameters, vibration parameters and stress parameters of each point under test in the scanning area. Step 10: Perform matrix fusion of topographic height data, vibration mode data, and stress distribution data to generate a multi-parameter in-situ fused image containing three-dimensional geometric information, vibration information, and stress information. 3.The laser differential confocal Raman spectrum topography-vibration-stress synchronous measurement method according to claim 2, characterized in that: The sensing model is established based on the physical characteristics of the absolute focus corresponding to the zero point of the differential confocal axial strength response curve. The measurement and control system (23) adjusts the voltage of the objective lens driver (5) through the PID control algorithm to maintain the differential signal at zero, thereby eliminating the defocus error caused by the vibration of the device under test (7).

4. The method for simultaneous measurement of morphology, vibration, and stress in laser differential confocal Raman spectroscopy according to claim 2 or 3, characterized in that: The step eight corresponds to the inversion calculation of stress value using formula wherein K is the Raman spectrum stress coefficient of the material, ω is the measured Raman spectrum characteristic peak center wave number, is the calibration wave number.

5. The laser differential confocal Raman spectrum topography-vibration-stress synchronous measurement method according to claim 2 or 3, characterized in that: In step six, the light intensity fluctuation signal is obtained by high-frequency sampling. The sampling frequency is at least twice the vibration frequency of the device under test (7) to satisfy the Nyquist sampling theorem and ensure the accuracy of the vibration waveform reconstruction.

6. The laser differential confocal Raman spectrum topography-vibration-stress synchronous measurement method according to claim 2 or 3, characterized in that: In step six, the fast Fourier transform demodulation process includes performing spectral analysis on the displacement waveform, extracting the main peak frequency as the vibration frequency, and extracting the main peak amplitude as the vibration amplitude, thereby achieving a quantitative characterization of the dynamic characteristics.

7. A laser differential confocal Raman spectrum topography-vibration-stress synchronous measurement device, characterized in that: It includes a light source system (3), a beam splitter (4), an objective lens driver (5), a measuring objective lens (6), a device under test (7), an XY scanning stage (8), a filter (9), a Raman spectroscopy detection system (13), a differential confocal detection system (22), and a measurement and control system (23); the light source system (3) is used to generate a highly coherent detection beam; The objective lens driver (5) is used to drive the measuring objective lens (6) to perform axial scanning and locking; the filter (9) is used to achieve spectral separation of Rayleigh scattered light and Raman spectral scattered light; the differential confocal detection system (22) is used to receive the reflected Rayleigh scattered light and generate a differential signal; the Raman spectral detection system (13) is used to receive the transmitted Raman spectral scattered light and collect the spectrum; the measurement and control system (23) is used to drive the hardware to work, perform data acquisition, signal demodulation and multi-parameter fusion processing.

8. The laser differential confocal Raman spectroscopy morphology-vibration-stress synchronous measurement device as described in claim 7, characterized in that: The light source system (3) consists of a laser (1) and a beam expander (2) and is used to provide collimated linearly polarized excitation light.

9. The laser differential confocal Raman spectroscopy morphology-vibration-stress synchronous measurement device as described in claim 7, characterized in that: Filter (9) is a notch filter. Its characteristics include high reflectivity for excitation light wavelength and high transmittance for Raman spectral scattered light wavelength.

10. The laser differential confocal Raman spectroscopy morphology-vibration-stress synchronous measurement device as described in claim 7, characterized in that: The differential confocal detection system (22) adopts a differential beam splitting structure, including a differential beam splitter (14), a front focal detection channel located in the reflected light path and a rear focal detection channel located in the transmitted light path; wherein the front focal detection channel is composed of a front focal converging mirror (15), a front focal pinhole (16) and a front focal detector (17), and the rear focal detection channel is composed of a reflector (18), a rear focal converging mirror (19), a rear focal pinhole (20) and a rear focal detector (21).

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