lumopt2#

The Lumerical photonic inverse design module lumopt2 provides a framework for the inverse design of photonic devices using Ansys Lumerical FDTD™. The following pages contains API documentation for the lumopt2 module.

Note

lumopt2 is only available in Ansys Lumerical FDTD™ version 2026 R1.2 and later.

Common lumopt2 API#

These classes are commonly used in the lumopt2 workflow, and you can directly initialize them from the top-level lumopt2 module.

Optimization project

Classes and functions for setting up the optimization project.

Classes

`Optimization`	Coordinates the optimization workflow for photonic inverse design.
`OptimizationResult`	Immutable result object returned from an optimization run.
`Project`	Main project class that coordinates parametrization, FOM, and solver.
`ProjectConfig`	A class used to modify the base simulation in the Project.
`FdtdSession`	A class to manage the FDTD simulation session.
`SimulationStatus`	FDTD simulation status codes.
`SimulationError`	Exception raised when a simulation fails.

Results and FoM

Classes and functions for handling simulation results and figures of merit.

Classes

`PortResults`	Container for port monitor simulation results.
`FieldResults`	Container for field monitor simulation results.

Functions

`Fom`	Factory function that returns either a `FieldFom` or `PortFom` instance.
`PNorm`	Create a p-norm based figure of merit function.

Parametrization

Classes and functions for parametrizing the simulation geometry.

Classes

`Parametrization`	Parametrized geometry using a user-defined function to map parameters.
`ClosedCurve`	A Beziergon - a polygon where edges can be linear or cubic Bezier curves.
`ClosedCurveLinearSegment`	A linear segment connecting two vertices
`ClosedCurveCubicSegment`	A cubic Bezier curve segment.
`CombinedParametrization`	Combine multiple parametrizations into a single parametrization.
`Segment`	Specification for a segment in Composite Bezier path.gy.
`EqualSplit`	Specification for splitting a segment into a parametric segment
`Parametrize`	Specification for making a segment parametric
`ParamVertex`	Specification for a parametric vertex adjustment.
`Box`	A 3D rectangular box defined by spans and centers or min/max coordinates.

Optimizers

Classes and functions for setting tools to calculate the gradient.

Classes

`ScipyOptimizer`	Wrapper for scipy.optimize.minimize optimizers, particularly L-BFGS-B.
`ParameterScaler`	Scales parameters between physical and normalized spaces.

Functions

`validate_bounds`	Validate parameter bounds and return lower/upper arrays.
`extract_fom`	Extract FOM value from objective function result.
`extract_fom_and_gradient`	Extract FOM and gradient from objective function result.
`finite_difference_gradient`	Compute the gradient of the figure of merit using finite difference.
`validate_gradient`	Validate the adjoint gradient by comparing it to a finite difference gradient for specified parameter indices.
`fd_sweep_perturbation`	Finite difference convergence test: compute the finite difference gradient for a range of perturbation values and plot the results.

Resources

Classes and functions for managing computational resources to run optimization.

Classes

`LocalRunner`	Class to manage simulation jobs locally.
`Job`	Class representing a single job.

Visualization

Classes and functions for visualizing optimization results.

Classes

`BaseCallback`	Base class for optimization callbacks.
`CallbackList`	Container for managing multiple callbacks.
`FileLogger`	Record the numerical history of one optimization run to a text file.
`GraphicalVisualizer`	Callback that visualizes optimization progress with live matplotlib plots.
`Panel`	Abstract base class for a single subplot in a `GraphicalVisualizer`.
`PanelState`	Immutable per-update snapshot handed to every panel's `update` call.
`FomPanel`	Live plot of the figure of merit vs.
`GeometryPanel`	Live plot of the current geometry on top of the initial baseline.
`GradientNormPanel`	Live plot of the gradient L2 norm vs.
`MonitorPanel`	Live plot of an FDTD monitor result (field component, S-parameter, ...).

Other

Classes and functions for logging, profiling, and other utilities.

Classes

Profiler

Aggregate wall-clock time per named category.

Functions

setup_default_logging

Configure the lumopt2 logger with sensible defaults.

All lumopt2 modules#

lumopt2.core

Modules for project configuration, optimization configuration, and FDTD session management.

lumopt2.core

lumopt2.fom

Modules to capture simulation results and define figures of merit from them for optimization.

lumopt2.fom

lumopt2.parametrization

Modules to parametrize the simulation.

lumopt2.parametrization

lumopt2.optimizer

Modules to set up and perform the optimization algorithm.

lumopt2.optimizer

lumopt2.utils

Utility modules.

lumopt2.utils