Wang Xun, Liu Zhirong, Zhao Daomu
J Opt Soc Am A Opt Image Sci Vis. 2014 Oct 1;31(10):2268-74. doi: 10.1364/JOSAA.31.002268.
Analytical expressions for the three components of nonparaxial propagation of a polarized elliptical Gaussian vortex beam in uniaxial crystal orthogonal to the optical axis are derived. Intensity and phase distributions of the three components of a polarized elliptical Gaussian vortex beam propagating in a uniaxial crystal orthogonal to the optical axis are illustrated by numerical examples. The influences of the initial beam's parameters and the parameters of the uniaxial crystal on the evolution of the beam's intensity and phase distributions in the uniaxial crystal are examined in detail. Results show that the statistical properties of an elliptical Gaussian vortex beam nonparaxially propagating in uniaxial crystal orthogonal to the optical axis are closely determined by the initial beam's parameters and the parameters of the crystal. The beam waist width ω not only affects the size of the beam profile in uniaxial crystal but also determines the nonparaxial effect of an elliptical Gaussian vortex beam. The profile of an elliptical Gaussian vortex beam in the uniaxial crystal becomes twisted and tilted, whether the elliptical factor α is greater or smaller than unity. The beam profile is tilted to the left in positive crystal. In contrast, it is inclined to the right in negative crystal. The results indicate that uniaxial crystal provides a convenient method to modulate the intensity and phase distributions of an elliptical Gaussian vortex beam, which is beneficial to optical manipulation of microscopic particles and nonlinear optics involving a specific beam profile and phase.
推导了偏振椭圆高斯涡旋光束在垂直于光轴的单轴晶体中进行非傍轴传播时三个分量的解析表达式。通过数值算例展示了偏振椭圆高斯涡旋光束在垂直于光轴的单轴晶体中传播时三个分量的强度和相位分布。详细研究了初始光束参数和单轴晶体参数对光束在单轴晶体中强度和相位分布演化的影响。结果表明,椭圆高斯涡旋光束在垂直于光轴的单轴晶体中进行非傍轴传播时的统计特性,在很大程度上由初始光束参数和晶体参数决定。束腰宽度ω不仅影响光束在单轴晶体中的光斑尺寸,还决定了椭圆高斯涡旋光束的非傍轴效应。无论椭圆因子α大于还是小于1,椭圆高斯涡旋光束在单轴晶体中的光斑形状都会发生扭曲和倾斜。在正晶体中光斑向左倾斜,而在负晶体中光斑向右倾斜。结果表明,单轴晶体为调制椭圆高斯涡旋光束的强度和相位分布提供了一种便捷的方法,这有利于对微观粒子进行光学操控以及涉及特定光斑形状和相位的非线性光学研究。