Design And Implementation Of Hardware For Laser Scanning Imaging System

This paper is based on the laboratory project of "one-dimensional high range resolution imaging system". The imaging mode and laser ranging methods are analyzed in detail, and the proposed research project of high-speed 3D-imaging is explained. The project adopts pulsed laser ranging in noncoherent detect mode, uses a 1064nm semiconductor pump YAG laser with high repetition frequencyas the laser source, detects object with a single APD, adopts an optics-mechanics scanner in object space to obtain images, and obtain distance images.Together with the actual project, a type of receiver cireuit which can be applied in high-speed laser range-finder is discussed in this paper in detail. Firstly, the laser echo signal is analyzed and discussed. The optical properties of object and backgroud are discussed. The characteristic of laser transmission in air is discussed. Based on these results, laser range equation is derived and calculates the laser echo power. Secondly, optoelectronic detection of the laser echo signal and an amplifier are researched in this paper. And then we analyze the noises in optoelectronic detectors and design the receiving circuit of pulsed laser echo signal. In the experimental system, APD transferrs laser pulse to weak electrical current. After preamplification we get a voltage pulse that has enough amplitude to be applied. The timing point is discriminated by the timing discriminator circuit. The flight time of pulse laser is measured accurately by SR620. At last, it is explained the test results and the progress of the work, gave some experience sum-up to the exploitation of 3D-imaging.