Spectral acquisition method for improving Raman spectral signal-to-noise ratio

Abstract

The invention discloses a spectral acquisition method for improving a Raman spectral signal-to-noise ratio, which relates to a spectral acquisition method. The method comprises steps: 1) spectrometerarray background noise SA is acquired; 2) an integral time spectral signal set of a series of microcells is measured; and 3) differential projection and inverse differential calculation are carried out to acquire a sample true spectrum Ss. Through shortening cell integral time, the measurement times in a fixed measurement time are increased; and the more sampling times are beneficial to reduce SG,the occurrence probability of SE is reduced, and through eliminating an abnormal unit, the influences of the SE are eliminated. The reduced cells S are accumulated, an SR response with a high signal-to-noise ratio under a fixed time is obtained, the SG amplitude is proportional to the square root of the cumulative times, and the SG is suppressed. The Raman spectral signal-to-noise ratio can be improved, the linear response of an instrument is improved, the cost of the instrument is reduced, the acquisition efficiency and the operation flexibility are improved, the burr on a baseline is eliminated significantly, and the cost performance of the instrument is improved.

Description

technical field [0001] The invention relates to a spectrum acquisition method, in particular to a spectrum acquisition method for improving the Raman spectrum signal-to-noise ratio. Background technique [0002] Spectral signal collected by spectrometer with array detector S , consisting of sequence values, S =[s1,s2,...,sn], as a whole sequence according to deterministic, including four parts: definite spectral signal S R , definite but time-dependent array noise S A , random Gaussian noise S G and uncertain interference S E ,which is: S = S R + S A (t) + S G + S E . [0003] in: [0004] S R It should have good linear responsivity, that is, the ideal spectrum is linearly positively correlated with the integration time, but in terms of physical properties, the linearity will become worse as the intensity increases. S A Caused by the individual differences between the photosensitive points of the array, because the manufacturing cannot guarantee that ...

AI Technical Summary

Problems solved by technology

[0006] The existing Raman spectrum acquisition method with high signal-to-noise ratio adopts the method of prolonging the integration time to increase the S R The long integration time also produces a series of problems: First, the acquisition time is long, plus the background acquisition time, a measurement needs 2 times the integration time length, due to the extension of time, it will lead to S E Increased chance of occurrence

The second is that the probability of random hotspots in the detector increases. In addition to random Gaussian noise, the array detector will also have irregular hotspot responses that significantly exceed the average amplitude of the noise. The longer the time, the greater the probability of hotspots; the third is the longer the integration time. , the probability of being interfered by cosmic rays is also greater; in addition, as the integration time prolongs, the array detection noise will significantly raise the baseline, and in severe cases, it will also affect the linear response of the signal

For a series of problems caused by prolonging the integration time, the current direct solution is to choose better quality and more precise array components, or suppress dark noise by reducing the detector temperature, so that the cost of the instrument is significantly increased

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