switchtolayout; widths = [0.4e-6, 0.45e-6, 0.5e-6, 0.55e-6]; for(i=1:length(widths)) switchtolayout; setnamed("waveguide", "y span", widths(i)); run; T = getresult("monitor", "T"); matlabsave("sweep_width_" + num2str(widths(i)*1e9) + "nm.mat", T); Use code with caution.
). The maximum allowed time step is governed by the CFL condition:
The Finite-Difference Time-Domain (FDTD) method is a state-of-the-art numerical technique used to model electromagnetic wave propagation in complex media. Instead of solving Maxwell's equations in the frequency domain, FDTD solves them in the time domain by replacing continuous spatial and temporal derivatives with finite differences. The Yee Lattice Topology At the heart of the FDTD algorithm is the Yee cell. : Electric (
The first object you add to a blank simulation is the FDTD Solver Region . This object defines the physical bounds of your simulation volume. Within its properties panel, you set the critical global parameters:
# Standard Lumerical Scripting Language select("FDTD"); # Select the region run; lumerical fdtd tutorial
: Performs an on-the-fly Fast Fourier Transform (FFT) from time-domain data to yield continuous-wave profiles (
If you want your simulation to be accepted in a peer-reviewed journal or a product tape-out, follow this checklist:
Back at her desk that night she opened the tutorial again—out of habit, gratitude, and a little nostalgia. The screen of step-by-step guidance looked the same: orderly, patient, ready. Mira realized that tutorials don’t just teach commands; they teach the habit of exploration: set up a simulation, test assumptions, refine parameters, and let the results reshape the questions you ask. She closed the tutorial and began another run, because the cavity still had whispers left to discover.
Once you master the single waveguide, expand your skills: switchtolayout; widths = [0
In the tab, set the Mesh Accuracy to 2 or 3 for rapid testing.
Repeat this process until the relative change in your metric drops below an acceptable threshold (typically High-Performance Scripting and Optimization
Aris started from scratch, treating it like a classic Lumerical FDTD tutorial . He carefully defined his physical structures—silicon on an insulator. He drew the rectangles with precision, ensuring the refractive indices were perfectly set for 1550 nm light. The Mesh and the Monitor
field. This process repeats sequentially for the duration of the simulation. Instead of solving Maxwell's equations in the frequency
While simple plane waves suffice for basic transmission, the is the powerhouse for scattering problems.
To demystify the process, let's walk through the standard workflow for setting up a simulation in Ansys Lumerical FDTD, using a nanohole array as an example.
As you progress, consider these practical tips to enhance your simulation efficiency and accuracy: