# Configuration
Configuration of the EME simulation parameters.
# Simulation Domain
Definition of the simulation domain size and position.
center: Center of the simulation domain in x, y, and z-directions.
Type: floating-point number
- Unit: m, μm (default), or nm
- Default: (0, 0, 0)
size: Size of the simulation domain in x, y, and z-directions.
Type: floating-point number
- Unit: m, μm (default), or nm
- Constraint: greater than or equal to 0
- Required field
# Background Medium
medium: Background medium of simulation, defaults to vacuum if not specified.
Options:
# Grid Specification
grid_spec: Specifications for the simulation grid along each of the three directions. This grid discretizes the structure cross-section for mode solving in the two transverse directions and is also used for field monitors. It is distinct from the EME grid defined under Cells & Modes, which divides the domain into cells along the propagation axis.
Options:
Default: AutoGrid with 10 minimum steps per wavelength.
# Symmetry
symmetry: Tuple of integers defining reflection symmetry across a plane bisecting the simulation domain normal to the x-, y-, and z-axis at the simulation center of each axis, respectively. Each element can be 0 (no symmetry), 1 (even symmetry, PMC plane), or -1 (odd symmetry, PEC plane). Using symmetry reduces the computational cost of the mode solves.
Default: (0, 0, 0)
NOTE
EME simulations terminate the mode plane with PEC boundaries. To absorb radiation leaving the waveguide, add PML layers in the mode solver using the Number of PML Layers setting of the mode specification.
# Advanced
# Constraint
constraint: Energy constraint for EME propagation, imposed at cell interfaces.
Options:
- None: unconstrained; may be faster for a large number of modes.
- Passive: energy can be dissipated but not created at interfaces. Can serve as regularization for the field continuity requirement and give more physical results.
- Unitary: energy is conserved at interfaces (but not necessarily within cells).
Default: Passive
# Normalize
normalize: Whether to normalize the port modes to unity flux, thereby normalizing the scattering matrix and expansion coefficients.
Options:
- False
- True
Default: True
# Store Port Modes
store_port_modes: Whether to store the modes associated with the two ports. Required to find the scattering matrix in a basis other than the computational basis, and to display the Port Modes dataset in the EME Results.
Options:
- False
- True
Default: True
# Store Coefficients
store_coeffs: Whether to store the internal forward/backward mode coefficients from the EME propagation. Mainly useful for debugging.
Options:
- False
- True
Default: False
# Subpixel Averaging
subpixel: Apply subpixel averaging methods of the permittivity on structure interfaces to result in much higher accuracy for a given grid size.
See: Subpixel Averaging
# Structure Priority Mode
structure_priority_mode: Determines the priority of structures that have no explicit priority. If Equal, those structures have the same priority; if Conductor, structures made of lossy metal or PEC media take priority over dielectric structures in regions of spatial overlap.
Options:
- Equal
- Conductor
Default: Equal