3D-Optical Simulation of MicroOLEDs With Multiple Dipoles Based on Finite Element Method

Abstract

Micro organic light-emitting diodes (microOLEDs) are gaining attention for next-generation augmented reality (AR) and virtual reality (VR) applications due to their compact form factors and high pixel density. However, traditional multilayer thin-film simulations—based on the assumption of dipole emitters embedded in infinite planar layers—fail to capture the three-dimensional optical effects of microOLEDs. This is primarily due to their micrometer-scale pixel size, which becomes comparable to the vertical dimensions of the device, and the presence of a pixel define layer (PDL). To address these limitations, finite element methods (FEM) and finite-difference time-domain (FDTD) methods are commonly employed. However, these methods typically demand substantial computational resources, limiting their uses to the illustration of specific optical characteristics and trends rather than enabling a full quantitative analysis. This study introduces an optimized FEM-based simulation method for micro-scale OLEDs embedded with multiple dipole sources. By incorporating randomly distributed dipole sources with varied positions, orientations, and relative phases, the proposed approach enables accurate far-field radiation pattern calculations while significantly reducing computational burden and simulation time, offering a promising pathway toward comprehensive optical analysis of microOLEDs and thus improving the understanding of light extraction and propagation at the micro-pixel level.