Fig. 1: Concept of focal stack imaging system enabled by focal stacks of transparent all-graphene photodetector arrays.
From: Neural network based 3D tracking with a graphene transparent focal stack imaging system
a Schematic showing simultaneous capture of multiple images of a 3D object (ball-and-stick model) on different focal planes. Transparent detector arrays (transparent blue sheets) are placed after the lens (green oval) to form the camera system. The depth information is encoded in the image stacks. Artificial neural networks process the image data and extract important 3D configuration information of the object. Inset: photograph of imaging system used in experiments with two transparent focal planes. b Upper panel: Optical image of a 4 × 4 transparent graphene photodetector array, scale bar: 500 μm. Upper-left corner is with false color and enhanced contrast in order to highlight the patterns. Lower panel: Schematic of the all-graphene phototransistor design. It includes a top graphene layer as transistor channel and a bottom graphene patch as floating gate, separated by a 6-nm silicon tunneling barrier (purple). The device is fabricated on transparent glass substrate (blue), and the active detector region is wired out with wider graphene stripes as interconnects.
