一种基于散焦光栅的光束质量M2因子实时测量技术 |
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引用本文: | 耿义峰,许晓军,习锋杰. 一种基于散焦光栅的光束质量M2因子实时测量技术[J]. 中国激光, 2008, 35(s1): 98-100 |
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作者姓名: | 耿义峰 许晓军 习锋杰 |
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作者单位: | 耿义峰:国防科学技术大学光电科学与工程学院, 湖南 长沙 410073 许晓军:国防科学技术大学光电科学与工程学院, 湖南 长沙 410073 习锋杰:国防科学技术大学光电科学与工程学院, 湖南 长沙 410073
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摘 要: | 设计出相位型正交散焦光栅,实现了一种新的光束质量M2因子实时测量技术。将散焦光栅和短焦透镜密接使用,透镜提供主要的聚焦能力,散焦光栅产生9个光轴,且在每个光轴上对焦距进行微调,使之具有不同的等效焦距,这样利用单一的CCD就可以在透镜焦平面上同时测量待测光束9个不同位置处的光强分布图样。利用二阶矩的方法计算束宽,经双曲线拟合得到光束的M2因子。对He-Ne激光器的输出光束进行了测量,得到其光束质量因子M2=5.775,与传统测量方法得到的结果相比,误差为5.1%。
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关 键 词: | 测量 激光光束质量 M2因子测量 散焦光栅 多平面成像 |
Real-Time Measurement of Beam Quality Factor M2 Based on Defocus Gratings |
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Abstract: | Crossed phase defocus gratings are designed and a new technique for real-time measurement of beam quality factor M2 is achieved. We can get the beam spots at 9 various positions to be measured simultaneously by using the defocus gratings closely connecting with a short-focal-length lens. The lens provides the majority of the focusing power and the grating provides 9 separate optical axes and effectively modifies the focal length of each axis. The value of M2 is determined by calculating the beam diameters using the second moment method and curve-fitting. A He-Ne laser beam is measured by using the gratings designed and a M2 value of 5.775 is achieved. Compared with a conventional measurement, the error is 5.1%. |
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Keywords: | measurement laser beam quality measurement of the factor M2 defocus grating multiplane imaging |
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