Light-splitting pupil laser differential motion confocal Brillouin-Raman spectrum measurement method and device

Abstract

The invention relates to a light-splitting pupil laser differential motion confocal Brillouin-Raman spectrum measurement method and device and belongs to the technical field of microscopic spectrum imaging. According to the method and the device, the high-resolution imaging of a three-dimensional geometric position of a sample is realized by constructing a light-splitting pupil confocal microscopic imaging system through using rayleigh scattering light abandoned in the confocal Raman spectrum detection; a zero crossing point of a light-splitting pupil laser differential motion confocal microscopic imaging device and a focal point of the zero crossing point are used for corresponding to the property to control a spectrum detector to accurately capture Raman spectrum information excited by a focus point of an objective lens so as to further realize the high-precision detection, namely image and spectrum combined high-space resolution detection on a microcell geometric position and spectrum information of a sample; meanwhile, the resolution capability and a measuring range are considered effectively; the characteristics of complementary advantages of a confocal Raman spectrum detection technology and a confocal Brillouin spectrum detection technology are utilized to design a confocal spectrum detection scheme for detecting by adopting a Raman spectrum and a Brillouin spectrum so as to realize the comprehensive measurement and de-coupling of multi-performance parameters of materials.

Description

technical field [0001] The invention belongs to the technical field of microspectral imaging, and relates to a method and device for measuring a split-pupil laser differential confocal Brillouin-Raman spectrum. The differential confocal microscopic technique is combined with the spectral detection technique to form a "spectrogram" The "integrated" high-resolution spectral imaging and detection method and device can be used for micro-area multispectral, multi-performance parameter comprehensive testing and high-resolution imaging of samples. Background technique [0002] The phenomenon of light emission widely exists in the interaction process between light and particles, that is, when a beam of light passes through a medium, the medium particles are affected by the light wave, transition from one quantum state to another quantum state, and radiate scattered waves at the same time, different The way of energy level transition produces Rayleigh, anti-Stokes and Stokes scatteri...

AI Technical Summary

Problems solved by technology

[0009] (1) The spatial resolution is not high, only about 1 μm

The intensity signal of the Raman spectrum excited by the laser is very weak, which is about 6 orders of magnitude lower than the intensity of the abandoned sharp beam. Therefore, in order to detect the extremely weak Raman signal, the aperture of the pinhole of the confocal Raman spectroscopy detection system is usually exist It is about 10 μm larger than the pinhole aperture value of the existing confocal microscope. As a result, the spatial resolution of the existing confocal Raman spectrum is only 1 μm, and since the confocal Raman spectrum detection technology was invented more than 20 years ago has not fundamentally changed

[0010] (2) Poor ability to capture the Raman spectrum excited by the focal point

Confocal Raman spectroscopy detection system, due to the insensitive intensity response at the extreme point, it is difficult to capture the Raman spectrum information of the sample excited at the focal point, thus limiting the spatial resolution of the existing confocal Raman spectroscopy detection ability;

[0011] (3) Long detection time and large system drift

Because the confocal Raman spectrum signal is very weak, the detector needs to be integrated for a long time (often several hours) when performing spectral imaging. The drift of the optical system and the sample worktable often causes the sample to defocus, which in turn reduces the confocal Raman. Spatial resolution of spectral detection;

[0012] (4) The stray light of the sample is strong, which affects the signal-to-noise ratio of the Raman spectroscopy detection instrument

The existing confocal Raman spectroscopic detection instrument adopts the back reflection sample detection method and the incident excitation optical path and the scattered light detection optical path are completely in the same optical path, which is bound to have the problem of large stray light interference of the sample, which limits the existing Spectral detection capability of confocal microscopes for highly scattering samples;

[0013] (5) The ability to measure multiple performance parameters needs to be improved urgently

However, because the differential confocal Raman spectroscopy test method adopts a dual-path physical pinhole structure, the structure of the differential confocal measurement system is relatively complicated, and the requirements for the defocus position are strict, and the installation and adjustment are difficult, which increases the error source; This method does not use the Brillouin scattering spectrum that contains rich sample information, and is still limited in the testing of materials such as elasticity and piezoelectric properties; in addition, due to the limitation of the principle of the differential confocal microscope system, it is usually difficult to balance the resolution and working distance. and field of view

[0015] Usually the intensity of the Raman spectrum scattered by the sample is 10 times the intensity of the reflected Rayleigh beam. -3 ~10 -6 times, while the conventional spectral detection instrument discards the Rayleigh beam which is stronger than the Raman scattered light

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