Finite Difference Time Domain Analysis of Three-Dimensional Sub-Wavelength Structured Arrays

The technical development of optical film coating to lower the reflected light and increase the optical efficiency of an optical system has been a very important issue for hundreds of years. Recently, the use of antireflection (AR) structured surface has been proposed as an applicable alternative based on both the theoretical and the experimental study. Antireflection structured surface was analyzed by the finite difference time domain (FDTD) method in the visible light spectrum. In the current study, we show the numerical calculation results of the AR structured surface by the designed three-dimensional (3-D) profiles using the FDTD method. Besides, the experimental results of the reflectance of different structure shapes and aspect ratios were carried out. The semi-spherical structure arrays were fabricated by holographic exposure and photolithographic processes on the polymer film. The optical property of the fabricated polymer film shows good agreement with the simulation results.