Spectral Acquisition Method for Improving Raman Spectral Signal-to-Noise Ratio

Abstract

A spectral acquisition method for improving the signal-to-noise ratio of Raman spectra, relating to a spectral acquisition method, comprising the steps of: 1) obtaining the background noise of the spectrometer array S A ;2) Measurement series of micro-unit integration time spectrum signal sets; 3) Differential projection and contrast differential calculation to obtain the real spectrum of the sample S s . The present invention increases the number of measurements within a fixed measurement time by shortening the unit integration time; more sampling times are beneficial to reduce S G , while reducing S E The probability of occurrence, and by eliminating abnormal units, eliminate S E Impact. Each unit after the present invention will restore S Accumulated to obtain a high signal-to-noise ratio at a fixed time S R response, of which S G The magnitude is proportional to the square root of the number of accumulations, so that S G get suppressed. The invention can improve the Raman spectrum signal-to-noise ratio, improve the linear responsivity of the instrument, help reduce the cost of the instrument, improve the collection efficiency and operation flexibility, significantly eliminate the burr on the baseline, and improve the cost performance of the instrument.

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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