Techniques for Applying the FDTD Method to the Electromagnetic Analysis of Diffractive Optical Elements

Abstract

Diffractive optical elements (DOEs) have been used in a variety of applications, including laser beam forming, fiber coupling, wavelength-division multiplexing, and optical signal processing. Applications like these often require DOEs that have feature sizes on a scale comparable to the wavelength of illumination. As a result, these DOEs require a complete electromagnetic (EM) model of diffraction to accurately analyze their performance. To this end recent years have seen the development and application of several computational EM methods, such as finite element methods (FEMs),1,2 boundary integral methods (BIMs)3–6 and finite-difference time-domain (FDTD) methods.7–9 However, while each of these methods has its own unique advantages,10 depending on the application, few are as general and well suited for the EM analysis of DOEs as the FDTD method. To this end, this presentation will discuss the efficient use of the FDTD in the analysis of DOEs.