Caballero-Benítez S F, Hacyan S
J Opt Soc Am A Opt Image Sci Vis. 2022 Jun 1;39(6):996-1006. doi: 10.1364/JOSAA.456358.
We present an ab initio numerical investigation of the internal conical refraction of structured light beams in a biaxial crystal. Starting from the solutions of the Fresnel equation, a theoretical analysis is developed without assuming any analytical approximation, thus obtaining a set of exact equations that can be solved by standard methods of integration for any impinging light beam. As examples of applications, we consider the particular cases of linearly and circularly polarized Gaussian and Bessel beams inside a KTP crystal. Numerical calculations follow the evolution of the refracted beam inside the crystal. It is seen that for realistic boundary conditions, a refraction cone appears in a certain range of distances within the crystal, and its shape is rather sensitive to the initial conditions.
我们对双轴晶体中结构光束的内圆锥折射进行了从头算数值研究。从菲涅耳方程的解出发，进行了理论分析，不做任何解析近似，从而得到一组精确方程，可通过标准积分方法求解任意入射光束。作为应用示例，我们考虑了KTP晶体内线偏振和圆偏振高斯光束及贝塞尔光束的特殊情况。数值计算跟踪晶体内折射光束的演化。可以看出，对于实际边界条件，在晶体内一定距离范围内会出现一个折射锥，其形状对初始条件相当敏感。
