Fig. 1. Fluorescence spectrum of fluorescent substance. (a) Fluorescence spectrum of riboflavin solution; (b) fluorescence spectrum of NADH solution

Fig. 2. Principle block diagram of aerosol microbial particle counter

Fig. 3. Overall light path structure

Fig. 4. Spot topography. (a) Original laser output spot; (b) shaping spot

Fig. 5. Optical denoising light path

Fig. 6. Detecting cavity structure diagram. (a) 3D design sketch; (b) picture

Fig. 7. Overall detection device

Fig. 8. Noise signal. (a) Without treatment; (b) after optical denoising processing; (c) after optical denoising and electrical denoising processing

Fig. 9. Fluorescence detection curve of 10 μm fluorescent microsphere. (a) Peak value of 350 mV; (b) peak value of 380 mV

Fig. 10. Fluorescence detection curve of 5 μm fluorescent microsphere. (a) Peak value of 250 mV; (b) peak value of 290 mV

Fig. 11. Fluorescence detection curve of 2 μm fluorescent microsphere. (a) Peak value of 130 mV; (b) peak value of 140 mV

Fig. 12. Fluorescence detection curve of 1 μm fluorescent microsphere. (a) Peak value of 78 mV; (b) peak value of 90 mV