Fig. 1. MPPC circuit diagram

Fig. 2. Schematic diagram of 3D imaging process

Fig. 3. Sequence diagram of TDC

Fig. 4. 3D imaging scene

Fig. 5. Schematic diagram of imaging

Fig. 6. Diagram of threshold voltage and photon event

Fig. 7. Target image

Fig. 8. Images of different threshold voltages

Fig. 9. Images of different aperture sizes

Fig. 10. Data statistics of unit (15,15) at 5 m

Fig. 11. Image at 37 m