Fig. 1. Shift difference Raman schematic
(a): Two single-wavelength Raman original spectra; (b): Differential Raman raw spectra; (c): The reconstructed Raman spectrum

Fig. 2. The relationship between the wavelength of the laser and its excitation and scattering efficiency

Fig. 3. Schematic diagram of the instrument structure
1: Laser line filter; 2: Reflecting mirror; 3: Laser dichroic mirror; 4: Rayleigh filter; 5: Spectrometer coupling focusing mirror;6: Spectral dichroic mirror; 7: Objective lens

Fig. 4. Shortwave pass spectrum dichroic mirror working curve

Fig. 5. Polystyrene Raman spectra under different detection methods
(a): Differential single wavelength 784.5 and 785.5 nm Raman detection results under synchronous test; (b): Differential single wavelength 784.5 and 785.5 nm Raman detection results under time-sharing sequential test; (c): Synchronous test near 1 064 nm Infrared Raman detection results; (d): 1 064 nm near-infrared Raman detection results under time-sharing successive test

Fig. 6. Acetone detection results based on multi-wavelength anti-fluorescence Raman spectrometer
(a1): Original acetone Raman spectrum; (b1): Acetone reconstructed Raman spectrum; (c1): Acetone 1 064 near-infrared Raman spectrum; (a2): Original acetonitrile Raman spectrum; (b2): Acetonitrile reconstructed Raman spectrum; (c2): Acetonitrile 1 064 near-infrared Raman spectrum

Fig. 7. The detection results of edible oil and red BBS plastic particles based on multi-wavelength de-fluorescence Raman spectrometer
(a1): Original edible oil Raman spectrum; (b1): Edible oil reconstructed Raman spectrum; (c1): Edible oil 1 064 near-infrared Raman spectrum;(a2): Original red BBS plastic particles Raman spectrum; (b2): Red BBS plastic particles reconstructed Raman spectrum;(c2): Red BBS plastic particles 1 064 near-infrared Raman spectrum

Fig. 8. Detection results of red wine and gray plastic particles based on multi-wavelength defluorescence Raman spectrometer
(a1): Original red wine Raman spectrum; (b1): Red wine reconstructed Raman spectrum; (c1): Red wine 1 064 near-infrared Raman spectrum; (a2): Original gray plastic particles Raman spectrum; (b2): Gray plastic particles reconstructed Raman spectrum; (c2): Gray plastic particles 1 064 near-infrared Raman spectrum

Table 1. Comparison of raw data of different detection methods