1.引言明年是激光器诞生二十周年,是它进入成年的一年。迄今已研制出各种各样的激光器,其应用也同时在向各个领域扩展。激光器的研制方向大约有二:一是以提高功率、改善效率为目的,另一的重点是激光器的质量而不是功率。作为应用典范,前者可举出加工和核聚变,后者可举出光通信、分光和计量 1. Introduction Next year is the twentieth anniversary of the birth of the laser, it is into an adult year. To date, a wide variety of lasers have been developed and their applications are expanding in all fields at the same time. The development of the laser about two directions: First, to improve power, improve efficiency for the purpose, the other focus is the quality of the laser rather than power. As an example of application, the former can be exemplified by processing and fusion, the latter by optical communication, spectroscopy and metrology