API Reference¶

The cockpit manual. Reference pages are organized by responsibility — fun is rationed here in favor of precision, because this is where you come mid-flight with a question.

RCWA & Results

The RCWA façade and the SimulationResult it returns — the two objects you'll touch every day.
Source

Plane-wave illumination: wavelength, angles, polarization.
Layers & Materials

Layer, Material, MaterialLibrary and the shipped database.
Shapes

Topology primitives: circle, ellipse, rectangle, ring, cross, polygon.
Inverse Design

MetaAtom, free, pixels, Target, optimize — declare, then evolve.
Fields & Visualization

FieldMap, reconstruct, and the matplotlib plotting helpers.
Tools

Convergence automation, HDF5 I/O, the material-import CLI.
Low-level

HarmonicGrid, convolution_matrix, solve_stack — the engine room.

Top-level exports¶

from ikarus import (
    RCWA,             # the main façade
    SimulationResult, # rich result object
    Source,           # plane-wave illumination
    Layer,            # a single stack layer
    Material,         # one optical material
    MaterialLibrary,  # registry of materials
    default_library,  # the shared built-in library (a MaterialLibrary instance)
    HarmonicGrid,     # Fourier-order bookkeeping
    shapes,           # topology primitives subpackage
)

Optional subpackages are imported explicitly:

from ikarus.inverse import MetaAtom, free, pixels, Target, optimize  # needs pymoo
from ikarus.visualization import plot_field, plot_stack, plot_topology  # needs matplotlib
from ikarus.tools import convergence, io

House conventions (memorize once)

Units: SI — meters for lengths, degrees for angles.
Time convention: \(\exp(-i\omega t)\); absorbers have \(k>0\).
n_orders = M keeps harmonics \(-M..+M\) per axis (count \(2M+1\), total \(P=(2M_x+1)(2M_y+1)\)).
A material specifier is a database name, a number (constant index), a JSON path, or a Material.