February 2026: Delivered precision and usability improvements to ModeSolver and EME components in tidy3d, including enhanced local subpixel averaging, reduced nonessential warnings, expanded docstrings, and increased EME interpolation points to 5. These changes improve numerical accuracy, developer experience, and align with FXC-4276.

2026-01 Monthly Summary: Delivered pivotal EME-related improvements in tidy3d that streamline data management, fix cross-component interpolation inconsistencies, and boost simulation reliability. The work reduces data churn, prevents misaligned specs across the EME pipeline, and lays a foundation for scalable production simulations, delivering tangible business value in performance and stability.

December 2025 monthly summary for flexcompute/tidy3d focusing on data management improvements and performance. Implemented EMESimulationData.coeffs to store coefficients from the EME solver for better debugging and traceability, with a targeted change to disable coefficient storage by default to improve runtime performance. Added compatibility validation to ensure existing configurations remain valid after the change. All work centered on delivering maintainable data models, safer defaults, and faster simulation setups in production pipelines.

November 2025: Delivered major enhancements to flexcompute/tidy3d, including nonlinear specifications support for custom media (NonlinearModel) and a suite of EME simulation optimizations. These changes broaden modeling capabilities, accelerate multi-frequency simulations, and improve robustness and usability through clearer validation and documentation.

October 2025 — Tidy3d improvements focusing on usability, reliability, and test coverage for tidy3d-extras in flexcompute/tidy3d. Delivered actionable error handling for initialization failures and strengthened packaging tests to accurately detect dependencies and subpixel availability. The changes reduce onboarding friction and support overhead while improving the robustness of import paths in production deployments.

September 2025 monthly summary for flexcompute/tidy3d focused on enhancing local simulation accuracy, robustness of the solver, and developer experience. Key outcomes include the introduction of the tidy3d-extras plugin to improve local mode solving accuracy via subpixel averaging, stricter bend radius validation with tests to prevent boundary-center errors, and a solver fix for named 2D materials on inhomogeneous substrates with improved subdivision validation and clearer structure naming. These changes deliver business value through improved simulation fidelity, reliability, and easier adoption via updated docs and packaging.

July 2025 monthly work summary highlighting reliability improvements and stability enhancements across the tidy3d suite and its notebooks, with a focus on preventing misconfigurations and improving notebook stability.

June 2025: Stabilized and extended EME simulation workflows in flexcompute/tidy3d. Delivered a consolidated feature that enhances boundary handling, symmetry expansion, and data capture control. The changes reduce setup errors, improve the accuracy of scattering matrices, and provide finer control over recordings, enabling faster, more reliable experimentation and clearer model validation.

Concise monthly summary for 2025-05 focused on business value and technical achievements for flexcompute/tidy3d. Highlights include solver reliability improvements, default behavior hardening for subpixel features, and clear documentation of numerical precision gains.

April 2025: Focused feature delivery in flexcompute/tidy3d, delivering end-to-end permittivity monitoring across Mode and EMESimulation, integrating local subpixel averaging with tidy3d-extras, and enabling 2D EME simulations. No major bugs fixed in this period; overall improvements center on measurement fidelity, test coverage, and configuration-driven workflows, delivering tangible business value by accelerating accurate material characterization and enabling more efficient simulation pipelines.

March 2025 monthly performance summary for flexcompute/tidy3d focusing on delivering feature-rich capabilities that expand modeling fidelity, improve user guidance, and enable multi-frequency EME workflows. Highlights include new AuxFieldTimeMonitor for nonlinear material models, a PML-area usage warning to prevent misconfigurations, and periodic repetition support for EME simulations. All features include associated tests, data structure updates, and changelog entries; no explicit critical bugs fixed this month, with emphasis on quality improvements and maintainability.

February 2025 monthly summary for flexcompute/tidy3d focusing on delivering physics-driven improvements and UX enhancements that increase accuracy, usability, and maintainability. Highlights include nonlinear field handling improvements with backward-compatible flag, field data overlap analysis, remote data patching for ModeSolver and web API, and enhanced dispersion fitter controls.

January 2025 performance summary for flexcompute/tidy3d: Strengthened numerical robustness and laid groundwork for scalable mode analysis. Delivered a foundational ModeSolver Simulation Framework while hardening cross-platform numerical validation. The work reduces platform-specific validation failures, improves maintainability, and enables future feature development in mode-enabled simulations.

Month: 2024-12 | Repository: flexcompute/tidy3d. In December 2024, delivered double-precision support for the Eigenmode Expansion (EME) solver, enabling more accurate simulations that require higher numerical precision. This replaces the prior single-precision-only implementation and introduces potential performance trade-offs to be balanced in future tuning. No major bugs were reported/fixed this month. Overall impact includes improved numerical reliability for EME workflows and a solid foundation for broader precision options in future releases.

Month 2024-11: Focused on hardening model correctness and improving user guidance in tidy3d. Implemented rigorous validation for anisotropic media definitions and introduced user-facing warnings for complex-field nonlinearities to promote safe usage and reduce misconfigurations. These changes improve stability, data integrity, and developer productivity by lowering the risk of invalid parameter combinations and guiding users toward preferred approaches.

September 2024: Delivered graphene fit quality warning suppression in tidy3d to reduce log noise and improve user experience for graphene simulations; completed a focused, maintainable change with minimal risk.