Depict the naissance , content , the infection to laser physics of microwave spectroscopy . clarify the innovation , breakthrough and accomplishment of c . h . townes ( the outrunner of laser physics ) in his maser invention 第三部分综述了激光物理在创立的前二十年( 60年代? 70年代)里的发展和主要的应用情况及其影响。