基于微透镜阵列光束均匀化的傅里叶分析

为了提高高功率固体激光器泵浦光束的均匀性,分析了成像型和衍射型微透镜阵列匀化光束的基本原理,基于菲涅尔衍射和傅里叶变换公式,推导出了微透镜阵列焦平面上光强分布的解析表达式,比较了两种光束微透镜阵列对光束匀化的效果。同时,研究了成像型微透镜阵列子透镜的相对孔径及微透镜阵列间距对光强分布的影响。结果表明,成像型微透镜阵列具有更好地匀化效果,且子透镜孔径是影响光束均匀性最主要的因素。

Fourier analysis of light beam uniformity based on the microlens array

In order to improve the uniformity of high-power solid-state laser pump light beam,the basic theory of beam smoothing with imaging microlens array and diffracting microlens array is analyzed.Based on the Fresnel diffraction theory and Fourier transform formula,intensity distribution stochastic solution of microlens array on focal plane has been derived and the homogeneous effects of two kinds of microlens arrays are compared.Meanwhile,the influences of relative aperture of one lenslet and the distance between two microlens arrays on the intensity distribution are researched.The results show that imaging microlens array is of better homogeneous effect and the relative aperture of one lenslet is a key factor to affect the uniformity of light beam.