Transmittance type confocal CARS (Coherent Anti-Stokes Raman Scattering) micro-spectrum testing method and device

Abstract

The invention belongs to the technical field of micro-spectrum imaging detection, and relates to a transmittance type confocal CARS (Coherent Anti-Stokes Raman Scattering) micro-spectrum testing method and a device. The key point of the method is that a laser confocal microtechnique is combined with a CARS spectrum detection technique, a bidirectional light splitting unit is added to a transmittance type confocal microstructure to implement nondestructive separation on Reyleigh scattering light and CARS light, the CRAS is adopted for spectrum detection, and the Reyleigh scattering light is adopted for geometrtic positioning. By virtue of the characteristic that the top point of a confocal curve precisely corresponds to a focus position, the position of an emitted spot focus is precisely captured and positioned, high-precision geometric detection and spectrum detection of high spatial resolution are achieved, and a method and a device for high spatial resolution spectrum detection on microcells of samples are formed. By using the CARS spectrum detection technique, excited Raman scattering light with information of a transparent sample is far stronger than conventional excited Raman light and is short in excitation time, so that possibility is provided for rapidly detecting biological samples and transparent materials. The method is accurate in positioning, high in spatial resolution, high in spectrum detection sensitivity, controllable in focus spot size measurement and wide in application prospect in fields such as biological medicines and transparent material detection.

Description

technical field [0001] The invention belongs to the technical field of microspectral imaging, and relates to a transmission-type confocal CARS microspectral testing method and device, which can be used to quickly detect the geometric shape of a transparent sample to be tested and obtain a micro-area CARS spectrum to achieve high spatial resolution. Tomographic imaging. technical background [0002] Due to the characteristics of Raman scattering itself, the traditional confocal Raman microscopy technique results in extremely weak scattering spectral signals. Even with high-intensity laser excitation, it still takes a long time to obtain a spectral image with good contrast. This long-term effect limits the application of Raman microscopy in the biological field. The coherent anti-Stokes Raman scattering (CARS) process based on the coherent Raman effect can greatly enhance the Raman signal, thus realizing fast detection. The coherent Raman effect is to lock the molecules on t...

AI Technical Summary

Problems solved by technology

[0004] Most of the existing CARS microscopy techniques use two single-wavelength lasers for spectral excitation, so only spectral information of a specific spectrum can be obtained, and the system’s fixed-focus capability is not emphasized, resulting in the actual spectral detection position often being in an out-of-focus position

Even the out-of-focus position can excite the Raman spectrum of the sample and be detected by the spectrometer behind the pinhole, but the intensity cannot reasonably represent the correct spectral signal intensity at this point

As a result, the ability of the CARS microscopic system to detect micro-region spectra is greatly limited, and it restricts its application in finer micro-region spectral testing and analysis occasions.

[0005] In addition, most spectral detection techniques and devices are based on reflective structures, which are not effective when detecting transparent materials

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