Grating Optimization and Analysis

Gratings are some of the most fundamental tools in the arsenal of any optical engineer. To design and analyze this kind of component, the fast physical optics modeling and design software VirtualLab Fusion provides its users with many helpful tools. These include the Parametric Optimization, to easily optimize your systems, and the Parameter Run, which allows you to perform parameter sweeps in order to study the influence of those parameters on the overall behavior of the setup. Furthermore, this enables the use to investigate effects introduced by deviations due to specific fabrication processes in detail. Different solvers are also put at your disposal for the simulation of the interaction of the field with the grating, with different assumptions and the corresponding levels of approximation. These range from the rigorous Fourier Modal method (FMM) to the Thin Element Approximation (TEA), which works well for larger structures with a shallow relief.

Thin Element Approximation (TEA) vs. Fourier Modal Method (FMM) for Grating Modeling

TEA vs. FMM Grating Modeling with optical design software
Two results on the diffraction efficiencies are shown. One for TEA and the other for FMM. The grating has a fixed period of d=1 micrometer with fixed TE polarization and fixed height h=815 nanometer.

Two commonly used, but very different algorithms for the analysis of diffraction efficiencies of gratings are investigated: TEA and FMM (also known as RCWA). The results from both methods are compared for two types of gratings (sinusoidal and blazed) with varying periods.

Parametric Optimization and Tolerance Analysis of Slanted Gratings

With the Fourier modal method (FMM) as the kernel on which parametric optimization is then applied, a slanted grating is designed to achieve high diffraction efficiency for coupling light into waveguides. Fabrication tolerances including rounded edges are analyzed in addition.

Meet us at OASIS 8

Meet us at OASIS 8