为了模拟不同光轴取向、光束发散角、晶体厚度或入射波长等参数下的单轴晶体锥光干涉，在 ASAP中定义起偏器、晶体、检偏器和接收屏的几何形状和光学特性，产生一组锥状高斯光束并设置其相干性和波动性，进行光线追迹、计算并显示接收屏上的干涉场能量分布。所得模拟结果表明，光轴与晶体表面垂直时，干涉条纹是 1组以光轴为圆心且被十字分割的内疏外密、明暗相间的同心圆环；平行时，是 2组分别以光轴的平行和垂直方向为对称轴的、内疏外密、明暗相间的双曲线；既不垂直也不平行时，条纹特征因光轴取向而异；当增大发散角、晶体厚度或减小波长时，干涉条纹都向内移动且条纹数增多，反之亦然；起、检偏器正交时的干涉条纹都和它们平行时的条纹互补。

In order to simulate conoscopic interference in uniaxial crystal under different optical axis directions, beam divergence angles, crystal thicknesses or incident wavelengths, a method of writing and running an Advanced System Analysis Program (ASAP) command script was adopted. Functions of main commands were as follows: define geometries and optical properties of a polarizer, a crystal, an analyzer and a plane for observing interferograms. Create a set of divergence Gaussian beams and specify their coherence and propagation. Trace rays, calculate and display the exact complex field energy distribution characteristic on the observing plane. Simulation results show that, when the optical axis is perpendicular to the crystal surface, the interferogram consists of concentric interference fringes centered on the optical axis and is separated by a cross. When the optical axis is parallel to the crystal surface, the interferogram consists of two sets of hyperbola interference fringes with their symmetrical axis separately perpendicular and parallel to the optical axis. Their fringe densities both increase from inside to outside. When the optical axis is neither perpendicular nor parallel to the crystal surface, characteristics of the interference fringe vary with the specific directions of the optical axis. Once increase the beam divergence angle and the crystal thickness, or reduce the incident wavelength, fringes of the interferogram will move toward inside with their numbers increasing, and vice versa. The interferogram appearing when the polarizer is perpendicular to the analyzer is complementary to that appearing when the polarizer is parallel to the analyzer.