基于夫琅禾费衍射的激光束散角外场检测

Outfield Measuring Method of Laser Beam Divergence Angle Based on Fraunhofer Diffraction

基于圆孔衍射原理,通过对菲涅耳衍射和夫琅禾费衍射特性的对比分析,综合圆孔夫琅禾费衍射光强艾里斑分布特征,提出了一种基于夫琅禾费衍射的激光束散角检测方法,通过布设激光靶对激光远场光斑进行采集、分析、处理,得到激光器关键性能参数束散角的实测值。测量结果表明:采用该方法可获得较高的检测精度,并对影响测量精度的因素进行了分析,该方法可为激光器束散角外场检测提供科学指导。

Based on the principle of diffraction for circular aperture, a comparison of characteristic between Fresnel diffraction and Fraunhofer diffraction is made. Integrating with light-intensity Airy disc distributing char- acteristic of Fraunhofer diffraction, a measurement method of laser beam divergence angle based on Fraunhofer diffraction is proposed. By collecting, analyzing and disposing far-field laser facula on the basis of arranging la- ser target, the real test values of laser beam divergence angle are gained. The test result shows that more precision can be got with the method. And the factors influencing on measuring precision are analyzed. The method will afford a scientific guidance for laser parameter outfield measurement.