Operating principles of a 3D photodetection and imaging system. a Schematic illustration and optical images of the system. Inset: magnified view. b Distribution of the devices and movement of the laser beam. c Photocurrent distribution on the hemisphere surface during movement of the laser beam. d Magnified view of the photocurrent distribution at the first position of the laser beam. The illuminating locations of the incident laser beam are estimated by interpolation. e Penetration of the laser beam at two points of the 3D hemispherical surface. f Photocurrent distribution on the hemisphere surface in the scenario of e. g Principle of estimating the incident direction of the laser from the photocurrent map