Study of reflectivity calculation errors in FDTD method with large angles of incidence

Abstract

The Finite-Difference Time Domain (FDTD) solution is one of the most important software for simulating nano-scale material optical response experiments. Nano-scale material optical experiments are often difficult to be performed and analyzed because of the difficulty to manufacture the material and detect signal precisely. FDTD is a much more convenient and cost-effective way of doing the experiment because of the maturity of the computer technology nowadays. This project aims to have some basic insight on how to set up a numerically stable model using the FDTD commercial license to simulate thin film and multilayer stack optical experiment. Reflectivity is being measured in the thin film and multilayer stack setup. In this setup, the error of oblique incident is investigated because large angle of incidence is known to decrease accuracy of FDTD. Materials are with different optical properties, if we arrange them in a special manner, the optical properties of the material can be amazing, for example creating a photonic band gap, enhancing the light extraction efficiency of OLED and suppressing reflection. The multilayer stack setup is a 1D photonic crystal structure which is the simplest arrangement of dielectric to change the material reflectivity.