Research On Optical Heterodyne Detection In Inverse Synthetic Aperture Lidar

Inverse Synthetic Aperture Lidar(ISAL), which is one of the latest innovation and development of imaging laser radar systems, is a kind of high resolution coherent laser radar based on Synthetic Aperture technique. Because its superior imaging performance theoretically and the wide application prospect both in national defense and civilian high resolution detection, this technology becomes a research focus around main counties of world in recent years.In this paper, one of the bottleneck technology-optical heterodyne detection technology is studied, the principle and advantages of optical heterodyne detection and the conditions should be met is also analyzed.The light field distribution of local light and signal light on detector photosensitive surface is studied, the paper also proceeds numerical simulation to study the influence of Collimation mismatch and offset mismatch on mixing efficiency on the basis of theoretical analysis. The paper also put forward an improving scheme. The situation that laser beam waist can’t accurate imaging to the detector surface will cause wave front mismatch, we analyze this problem and summarize the solutions given in the literatures coherent.we also do research how to select a detector for ISAL and the APD circuit are introduced, several subcircuits, including APD receving circuit, transresistance circuit, voltage controlled amplifier circuit and power circuit are studied.