高斯型激光束在圆孔衍射过程中的光束畸变

The Gaussian laser beam distortion in circular aperture diffraction

由于激光畸变所产生的现象及其形成的物理机制十分丰富,对畸变激光传输特性的研究已然成为一个重要的光学类课题。对此本文将以激光的圆孔衍射作为切入,采用Zernike多项式函数拟合相位畸变元件的方法,探讨具有高斯型分布的激光束在圆孔衍射过程中的光束畸变。进一步分析波长、传播距离及函数的阶数对光束畸变的影响。结果显示,在畸变影响下,由于相散畸变因子作用导致光束发生对称性退化,引起光束发生分裂,中心光强位置发生偏移,产生像散和离焦畸变现象。而Zernike多项式函数中q值会显著影响畸变中光束发生分裂的数量,且随激光波长和传播距离的增大,其畸变影响增强,像散和离焦变得越明显。

Due to the abundant phenomena of the laser distortion and the physical mechanism of its formation,the research of distortion laser transmission characteristics has become an important optical topic.Therefore,in this paper,by applying the circular aperture diffraction of the laser,and adopting the method of fitting the phase distortion element with the Zernike polynomial function,the beam distortion of the laser with Gaussian distribution during the circular aperture diffraction has been discussed.For further study,the effects of the wavelength,the propagation distance,and order of the function on beam distortion have been analyzed.The results have shown that,under the influence of distortion,due to the effect of the astigmatic distortion factor,the beam degrades symmetrically,which leads to splitting,the position of the central beam intensity is shifted,causing the astigmatism and defocusing distortion.The q value in the Zernike polynomial function significantly affects the amount of beam splitting during distortion,as the laser wavelength increases,the distortion effect increases as well,and astigmatism and defocusing become more obvious.