FDTD Engine Features

The OmniSim and CrystalWave frameworks includes a highly efficient FDTD (finite difference time domain) engine to simulate the propagation of light through your designs. Below is just a partial list of all the powerful features of the FDTD engine.

Finite Difference Time Domain (FDTD) simulation of a photonic crystal Y-junction

Finite Difference Time Domain (FDTD) simulation of a photonic crystal Y-junction

Overview

  • 2D and 3D FDTD engine

  • Native 64-bit version: virtually unlimited memory!

  • Very fast speed optimised algorithm.

  • Supports clustering and SMP, allowing you to take benefits of multiple CPU cores either one computer or across a computer cluster.

  • More memory efficient than competing products.

  • Advanced memory reducing techniques (including new running transform)

  • Sub-gridding - ability to create 2x, 4x or greater increased resolution in localised regions. 4x subgridding can accelerate a 3D simulation by up to 64x. This is vital for modelling thin metals or small objects accurately, e.g. Mie scattering.

Adaptative resolution obtained with a Sub-Gridding region
Resolution of the FDTD Engine increased locally with a sub-gridding region
(the boundary of the sub-gridding region is shown with a white line)

Materials

  • Transparent and lossy materials

  • Dispersive materials including metals, including Debye, Drude and mixed Drude/Lorentz models - and automatically generate model parameters from a supplied dispersion spectrum.

  • Non-linear materials including chi2 and chi3

  • Anisotropic refractive index - general symmetric tensor

  • Magnetic materials.

Boundary conditions

  • High performance PMLs on all six faces

  • Dispersive PMLs e.g. to match metals touching the boundaries

  • Metal, magnetic and periodic boundary conditions

Sources

  • Built-in mode solver for excitation of waveguide mode.

  • Single dipole source or volume of incoherent dipoles (eg for modelling an LED).

  • Plane wave source, Gaussian profile source.

  • Arbitrary beam source, including beam direction, focal point, polarisation and intensity profile.

Sensors

  • Measurement of power in waveguide modes using built-in mode solver, or import of FIMMWAVE modes.

  • Frequency domain results: Fourier analysis

  • Q-Factor calculator - calculate Q in typically 1/4 the time compared to using a Fourier Transform

  • Built-in Farfield Calculator

  • Net flux, forward flux and backward flux sensors, versus time, frequency or wavelength. Profile sensors - any field versus (x,y), (x,z) or (y,z) at chosen wavelength.

  • Box sensors - measure total flux in/out of a box - useful for e.g. photo detector efficiency simulation

Additional features

  • Storing / Restoring results from an FDTD calculation

  • Batch manager - submit multiple jobs to the engine at same time.

  • Run time monitoring of evolving fields

  • Video capture - generate a video of your FDTD simulation using any codec installed in your PC.  

Optional modules for the FDTD Engine