Analysis of finite diffractive optical elements.

摘要

Diffractive optical elements are becoming increasingly popular devices as a result of their extreme versatility, small size and weight, high efficiency, and their ability to be integrated with other devices. Advances in fabrication techniques such as microphotolithography have made it possible to produce higher quality devices with smaller features and at a lower cost than ever before. Among the many applications of diffractive elements are revolutionary new technologies such as optical interconnections.; In order to design and characterize the performance of diffractive optical elements, accurate methods of analysis are needed. In this work, rigorous and scalar integral methods are used to analyze various types of finite, possibly aperiodic, diffractive elements. To begin with, the various rigorous and scalar integral methods are unified into a single hierarchical framework. The accuracy of the scalar methods is then evaluated in the context of focusing diffractive lenses using the rigorous boundary element method (BEM) to obtain the true diffractive characteristics. Metallic focusing diffractive mirrors are also analyzed using the rigorous BEM to evaluate their performance in various focusing configurations. Finally, an efficient multiple layer BEM formulation is used to study the effects of finite beam and finite grating size on the behavior of polarizing and resonant subwavelength gratings.