This guide provides a foundational workflow for setting up and running a simulation in Ansys Lumerical FDTD , the industry standard for modeling nanophotonic devices. 1. Layout and Material Setup Define Geometry Structures
button to add primitive shapes (rectangles, cylinders) or import GDSII files. Assign Materials : Open the Material Database
to select from pre-defined models like Silicon (Si) or Gold (Au). Ensure the "Mesh Order" is set correctly for overlapping objects. 2. Simulation Region & Meshing FDTD Solver : Add an FDTD simulation region. Set the tab to cover your device. Boundary Conditions : For most photonic chips, use PML (Perfectly Matched Layer) to absorb outgoing waves and prevent reflections. Use Symmetric/Anti-Symmetric boundaries to save memory if your design is periodic. Mesh Settings
: Use a "Mesh Accuracy" of 2 or 3 for initial testing; increase to 4+ for final publication-grade results. 3. Sources and Monitors Add Source : Choose a Plane Wave for bulk materials or a Mode Source for waveguides. Set the wavelength range (e.g., 1.5 for C-band telecommunications). Insert Monitors Frequency-Domain (Power)
: To capture transmission, reflection, and electric/magnetic field profiles ( Time-Domain
: To verify that the fields have decayed before the simulation ends. ResearchGate 4. Running and Analysis Check Layout : Click the button to ensure the mesh and boundaries are valid. Run Simulation : Click the
button. Monitor the "Shutoff Level"; the simulation should reach 10 to the negative 5 power or lower for converged results. Visualize Data : Right-click on your monitors after completion and select (transmission) or (reflection) versus wavelength. For more advanced workflows, you can explore the Ansys Optics Learning Center
for specific examples like grating couplers or metasurfaces. ResearchGate lumerical fdtd tutorial
This draft post provides a comprehensive overview of the Ansys Lumerical FDTD workflow, designed for researchers and engineers transitioning from theoretical Maxwell's equations to practical optical device simulation.
Getting Started with Ansys Lumerical FDTD: A Step-by-Step Guide
Lumerical’s Finite-Difference Time-Domain (FDTD) solver is a premier tool for modeling light at the sub-wavelength scale. Whether you are designing silicon photonic waveguides or analyzing plasmonic nanoparticles, the software provides a robust environment to study light propagation and scattering. 1. The Core Simulation Workflow
A standard FDTD simulation follows a structured five-step lifecycle:
Layout Setup: Define your materials and geometric structures.
Simulation Region: Add the FDTD solver region and define boundary conditions, such as PML (Perfectly Matched Layers) to absorb outgoing waves.
Sources: Inject light using sources like Plane Waves, Total-Field Scattered-Field (TFSF), or Mode sources. This guide provides a foundational workflow for setting
Monitors: Place frequency-domain or time-domain monitors to collect data like transmission, reflection, and field profiles.
Analysis: Run the simulation and use the Visualizer to inspect results. 2. Setting Up Your First Project
When starting from scratch, your primary interface is the Layout Editor. Lumerical FDTD Nanophotonic Scattering Tutorial (Part 1)
hello everyone i'm Josh. and today I want to walk you through how to set up a scattering simulation using Lumericals FTD software. YouTube·Computational Nanophotonics Videos FDTD product reference manual - Ansys Optics
The tutorial structures learning around three critical phases of simulation:
1. Structure Building and Material Modeling Users learn to define geometries (rectangles, circles, polygons) and assign material properties from Lumerical’s extensive database. However, the tutorial goes deeper by introducing conformal mesh technology, which adjusts the dielectric constant at material boundaries to reduce "staircasing" errors—a direct application of the effective medium approximation.
2. Source Engineering The tutorial systematically covers source types: total-field/scattered-field (TFSF) sources for scattering problems, mode sources for waveguide injection, and dipole sources for spontaneous emission studies. For each, it explains how to set the pulse width to balance frequency resolution with simulation time, directly tying the user’s actions to the Fourier transform limits. Complete all built-in examples in Lumerical (Help >
3. Boundary Conditions and PML Perhaps the most critical practical skill is the placement of Perfectly Matched Layers (PMLs). The tutorial includes a dedicated module showing how to position PMLs at least half a wavelength away from scatterers to avoid evanescent-field interactions. It also contrasts PML with periodic (Bloch) boundaries for metasurface simulations and metal boundaries for plasmonic waveguides.
A typical FDTD (Finite-Difference Time-Domain) simulation follows a standard lifecycle:
Layout Mode: Define your materials, structures, and solver parameters.
Run Mode: The software discretizes the space into a "Yee mesh" and solves Maxwell's equations over time.
Analysis Mode: Retrieve and process data (like transmission or field profiles) from monitors. 2. Setting Up Your First Simulation
You can find comprehensive introductory courses on the Ansys Innovation Space. Ansys Lumerical FDTD Intro — Lesson 1