Lumerical Fdtd Tutorial Jun 2026
Back-reflection or scattering due to poor mode injection or mesh discontinuities.
The simulation region defines the boundaries of your virtual experiment. Click the button and add an FDTD region. Geometry Tab : Match the spans to your structure. Boundary Conditions Tab :
What specific are you simulating (e.g., grating coupler, metasurface, microdisk)?
H_z (face center) | +-- E_y (edge center) / E_x (edge center) Courant-Friedrichs-Lewy (CFL) Stability Criterion lumerical fdtd tutorial
: Calculate transmission, reflection, and field profiles.
). Use these to calculate transmission, reflection, and absorption spectra. Advanced Mesh Engineering and Convergence Testing
Lists all simulation components, sources, and monitors. Back-reflection or scattering due to poor mode injection
The difference between a novice and an expert is the . Spend 80% of your time validating your mesh. The remaining 20% is for physics.
Lumerical provides a comprehensive material database (e.g., Si, SiO₂, Au, Ag) with wavelength-dependent refractive indices (n, k). Users can also define custom materials using models like Lorentz or Drude for dispersive media. The photonic crystal slab—a layer of silicon with a periodic array of air holes—is constructed using primitive geometric objects (rectangles, cylinders) from the layout editor. Boolean operations and parameter sweeps allow for complex, parameterized designs.
). The maximum allowed time step is governed by the CFL condition: Geometry Tab : Match the spans to your structure
The FDTD method is based on the following steps:
: Absorbs all outgoing light. Use this for open boundaries where light escapes into infinity.
E = getresult("monitor", "E"); x = E.x; y = E.y; E2 = E.E2; # Electric field intensity |E|^2 image(x*1e6, y*1e6, E2(:,:,1,1), "X (um)", "Y (um)", "Field Intensity Profile"); Use code with caution. 6. Troubleshooting Common Simulation Errors Root Cause
: Utilize built-in shapes (rectangles, cylinders, spheres) or import custom CAD geometries (GDSII, STL, STEP).
To reduce simulation time by half if the structure has symmetry. Step 2: Define Materials and Geometry