公开(公告)号：US5042950A

公开(公告)日：1991-08-27

申请号：US526757

申请日：1990-05-22

Applicant: Joseph T. Salmon, Jr.

Inventor： Joseph T. Salmon, Jr.

IPC: G01J1/42 ,  G01J9/02

CPC classification number: G01J9/0215 ,  G01J1/4257 ,  G01J2009/0238

Abstract: An apparatus and method is disclosed for accurate, real time monitoring of the wavefront curvature of a coherent laser beam. Knowing the curvature, it can be quickly determined whether the laser beam is collimated, or focusing (converging), or de-focusing (diverging). The apparatus includes a lateral interferometer for forming an interference pattern of the laser beam to be diagnosed. The interference pattern is imaged to a spatial light modulator (SLM), whose output is a coherent laser beam having an image of the interference pattern impressed on it. The SLM output is focused to obtain the far-field diffraction pattern. A video camera, such as CCD, monitors the far-field diffraction pattern, and provides an electrical output indicative of the shape of the far-field pattern. Specifically, the far-field pattern comprises a central lobe and side lobes, whose relative positions are indicative of the radius of curvature of the beam. The video camera's electrical output may be provided to a computer which analyzes the data to determine the wavefront curvature of the laser beam.

Abstract translation: 公开了一种用于精确实时监测相干激光束的波前曲率的装置和方法。 知道曲率，可以快速确定激光束是准直的，还是聚焦（会聚）或去聚焦（发散）。 该装置包括用于形成待诊断的激光束的干涉图案的横向干涉仪。 干涉图案被成像到空间光调制器（SLM），其空间光调制器（SLM）的输出是具有印在其上的干涉图案的相干激光束。 SLM输出集中在获得远场衍射图。 诸如CCD的摄像机监视远场衍射图案，并且提供指示远场图案的形状的电输出。 具体地，远场图案包括中心凸角和旁瓣，其相对位置指示梁的曲率半径。 摄像机的电输出可以被提供给分析数据以确定激光束的波前曲率的计算机。