Research on passive low-light-level optical fiber endoscope detection system

Abstract

A passive low-light-level optical fiber endoscope detection imaging system is studied by combining optical fiber endoscope technology with high sensitivity EMCCD low-light-level imaging technology. On the basis of designing the overall system, the hardware with dual-mode switching function is constructed by using ordinary color camera and low-light-level camera. The USAF1951 resolution board is used to test the resolution of the system. The results show the white light lateral resolution of the system of 70.1 µm, the night vision lateral resolution of 180 µm. The average value of Bhattacharyya coefficient is 0.8681, indicating that the system can effectively avoid light leakage. In the environment of illuminance of 0.5 Lux, the image frame rate of the system is greater than 25 Hz, indicating that the system has fast imaging speed under low illumination. The imaging gain of the system can be up to 1000 times, indicating that the high-sensitivity low-illuminance camera has excellent imaging ability under low light conditions. After calculation, the system has a field of view of 66.4 cm2, which is more suitable for observing rodents. The passive low-light-level optical fiber endoscope detection imaging system has highly sensitive detection performance under weak light environment such as rodent caves, where active lighting is not suitable.