Optical System Design And Stray Light Processing Method Of Wide Band Single-cell Raman Spectrometer

Raman spectroscopy for biological detection has the advantages of no fluorescent labeling,no water interference,and a real-time dynamic analysis of live cells.It has great application potential in clinicopathological analysis,surgical guidance and biological research.However,due to the weak signal of Raman scattered light itself,it is impossible to increase the signal by increasing the laser power during the single-cell analysis process,so the inhibition of stray light is particularly important.At the same time,due to the wide spectral range of single-cell fingerprint spectrum and the high spectral resolution requirements,the rotating grating structure is needed,which brings the difficulty of optical system optimization and stray light inhibition.In view of the needs of cancer cell identification and typing,this paper,based on the review and analysis of relevant technology development at home and abroad,studies the optical system and single-cell Raman spectrometer with wide band,high resolution and low stray light,which are divided into the following main contents:（1）In order to meet the designed Raman spectrometer for the accurate analysis of cells and other biological samples,the requirements of wide band,high resolution and low stray light are put forward for the spectrometer.The Chenier-Turner（Czerny-Turner）M optical path structure which is convenient to adjust and can avoid multiple diffraction is selected,and the contradiction between spectral resolution and band range of the spectrometer is solved by segmented scanning.（2）Select the plane grating as the dispersion element.On the basis of deep analysis of the spectrometer aberration theory and the spectral bandwidth factors,a design method of the initial structure of the spectrometer is given.Zemax software was used to complete the optical system design of the single-cell Raman spectrometer,and the theoretical spectral resolution is better than 0.06nm from 530 nm to 1000 nm.（3）For the mechanism of single-cell Raman spectrometer system,based on the principle of system light machine structure,put forward a method of optical trap under multiple structure,using Trace Pro software to analyze the inhibition of stray light,stray light suppression at different wavelengths reduced by 12%～47%,Raman spectrometer overall stray light level is lower than 10^-6.