ABSTRACT
Chapter 21, Uniaxial Materials and Components, explores light propagation and ray tracing in common uniaxial devices. This chapter simplifies the birefringent ray trace and polarization ray tracing methods to analyze uniaxial materials, the most common anisotropic materials used as optical components, such as calcite and uniaxial devices such as waveplates. The algorithm allows optical design software to trace rays through general systems of birefringent materials. Understanding the resultant wavefronts and their aberrations aids in finding suitable configurations of optical elements and balancing aberrations. This chapter presents the index ellipsoid or the optical indicatrix, which represents the dielectric tensor in shape of an ellipsoid to help visualize the birefringent wavefronts propagating through birefringent interface.
Uniaxial materials are a special case of biaxial materials with two equal principal refractive indices; thus the two corresponding principal axes become degenerate. The wavefront aberrations induced by the birefringent material vary with the polarization of the light and the direction of propagation. Uniaxial materials, such as calcite and quartz, are frequently used to generate phase delays between eigenpolarizations or to divide wavefronts based on polarization and direct these components into different directions. In uniaxial materials, the extraordinary mode’s birefringent aberrations are complicated due to an angularly varying refractive index. It is important to understand such aberrations in analyzing waveplates.
