Fig. 1. LIF system structure diagram

Fig. 2. Fluorescence spectra of four samples

Fig. 3. (a) Fluorescence spectra of samples with same brand and different degrees; (b) local diagram of the first wave peak; (c) local diagram of the second wave peak; (d) local fluorescence spectra in band of 465-500 nm

Fig. 4. (a) Fluorescence spectra of samples with different brands and same degree; (b) local diagram of the first wave peak; (c) local diagram of the second wave peak; (d) local fluorescence spectra in band of 465-500 nm

Fig. 5. (a) Fluorescence spectra of samples with different brands and same degree of 42; (b) local diagram of the first wave peak; (c) local diagram of the second wave peak; (d) local fluorescence spectra in band of 465-500 nm

Fig. 6. Spectra of the input model. (a) Sample A; (b) sample B; (c) sample C; (d) sample D

Fig. 7. Deep learning model flow chart

Fig. 8. Deep learning model training process curves