In this thesis, we determine and implement an optical propagation technique suitable for system-level simulation of optical micro-systems. The Rayleigh-Sommerfeld formulation is selected as the optical propagation modeling technique because it satisfies the requirements of a system-level CAD tool and supports accurate modeling at propagation distances on the order of the wavelength of light. We present an efficient solution to the Rayleigh-Sommerfeld formulation using the angular spectrum technique which uses the fast Fourier transform to decompose the complex optical wavefront into plane waves propagating from the aperture to the observation plane. This technique reduces the computational order of solving the Rayleigh-Sommerfeld formulation from a brute force direct integration technique of O(N4) to a computational order of O(N2logN).
For use in a design environment, we present an error analysis of our technique. Errors are caused by the discrete sampling of the optical wavefront over a finite range to approximate the infinite continuous Fourier transform. Methods for reducing both aliasing and truncation errors are presented, along with techniques to estimate the remaining errors of the angular spectrum technique. We perform a rigorous error estimate on several common optical wavefronts and provide techniques to perform an error analysis on a general wavefront. The utility of this method is shown by implementing the work into a mixed-signal, multi-domain CAD tool, in which we perform system-level simulations and analyses of several optical MEM systems.
