▎ 摘　　要

NOVELTY - The system has a graphene/germanium based photoconductive position sensitive detector for finishing photoelectric conversion of an incident laser, and outputting 4 paths of photocurrent signals under working condition of a bias circuit. An analog signal processing module realizes optical current signal conversion amplification, filtering output by the bias circuit, differential operation and peak detection output. An analog-digital (A/D) conversion circuit is controlled by a field programmable gate array (FPGA). An analog switch forms a data collecting and processing module. The FPGA adjusts the analog switch according to a sampling voltage value, realizes automatic gain control of an automatic gain differential operation circuit, and performs algorithm processing to the digital voltage value to output a spot position coordinate. USE - Light spot position detecting system based on a position sensitive detector of graphene-germanium base for use in a photoelectric technical field. Uses include but are not limited to receivers, recorder and signal collecting system, optical fiber communication, microwave communication system, satellite and TV. ADVANTAGE - The system improves signal-to-noise ratio, optimizes a system structure, and enhances scene applicability, when the data collecting and processing module realizes digital processing of peak voltage through an FPGA control A/D module, and automatically adjusts an analog switch channel according to the converted voltage value. The system realizes automatic gain control, and reduces influence of dark current and noise to improve precision and stability. DESCRIPTION OF DRAWING(S) - The drawing shows a block diagram of a light spot position detecting system based on a position sensitive detector. (Drawing includes non-English language text).