一、前言随着激光技术的应用,对激光束光斑大小的测量就愈显得重要。例如,要确定腔外光腰位置、激光束的发散角测量、测定或检验经扩束聚焦等变换后激光束的大小等,都需要进行光斑大小的测量。测量毫米级光斑的方法较多,这儿就不一一列举。可是,当光斑尺寸小至与光波长可比拟的程度,或对应其波长已到极限(例如He- I. INTRODUCTION With the application of laser technology, the measurement of laser beam spot size becomes more and more important. For example, it is necessary to measure the spot size in order to determine the position of the outer waist, the divergence angle of the laser beam, and the size of the transformed laser beam after the measurement or verification of the expanded beam. There are many ways to measure millimeter-level flare, not to mention here. However, when the spot size is as small as comparable to the wavelength of light or to the limit of its wavelength (eg, He-