Fig. 1. Imaging schematic of wide field microscope and confocal microscope. (a) Wide field microscope; (b) confocal microscope

Fig. 2. Schematic of the Nipkow disk^[17]

Fig. 3. Different confocal scanning methods and scanning schematic on the sample plane. (a) (e) Single point scanning confocal microscopy based on GM; (b) (f) confocal microscopy using Nipkow disk; (c) (g) parallel scanning confocal microscopy based on SLM; (d) (h) line scanning confocal microscopy

Fig. 4. Laser differential confocal for axial localization. (a) Laser differential confocal^[37]; (b) divided-aperture differential confocal^[45]

Fig. 5. Dual-detection confocal for axial localization^[49]

Fig. 6. Spectrally encoded confocal microscopy^[53]

Fig. 7. Confocal imaging system. (a) Schematic of dispersion confocal imaging system^[59]; (b) principle of dispersion confocal fast detection based on transmission detection^[60]