How to design coupling from an optical fibre into a photonic chip using a microlens and an edge coupler: fibre mode analysis in Lumerical MODE, alignment evaluation with POP in OpticStudio, and analysis of the coupling region with FDTD and EME.
A practical guide to working across Lumerical and Zemax OpticStudio: ZBF file exchange, FDE mode analysis, overlap analysis and improving fibre coupling efficiency, with the settings that matter at each step.
Bloch boundary conditions in Lumerical FDTD and MODE: how they differ from periodic boundaries, the phase correction for oblique incidence, and the cost of complex-valued fields (twice the memory and twice the time). Also covers when to use BFAST instead and the Source Angle setting that prevents boundary scattering.
varFDTD in Lumerical MODE treats a 3D waveguide structure as an efficient 2D model, which makes propagation analysis far faster. This article covers how it differs from FDTD, BPM and EME, benchmarks speed against accuracy, and shows where it fits in PIC design.