一、前言激光技术是近十多年来才发展起来的一门尖端技术。由于激光具有特别优良的单色性、方向性和极高的亮度,所以,它的出现,从根本上突破了以往普通光源的种种局限性,使它在通讯、雷达、测距、自动控制、计量技术、精密加工、数据贮存等重要技术领域内日益得到广泛的应用。此外,在光谱学、生物学、医学等方面也有重要的应用。因此,十几年来,激 I. Introduction Laser technology is a cutting-edge technology developed in the last decade or so. As the laser has excellent monochromaticity, directionality and high brightness, so its appearance, fundamentally broke through the limitations of the previous ordinary light source, it is in communication, radar, ranging, automatic control, Metering technology, precision machining, data storage and other important technical areas are increasingly widely used. In addition, there are also important applications in spectroscopy, biology and medicine. Therefore, more than a decade, excited