Rectangular Y-junction power split vs Tidy3D

Rectangular Y-junction power split vs Tidy3D#

validated · 2026-08-28

forwardresolution 1parityp4picy_junctiontidy3d_goldenhigh_yield

This case compares a local FDTDX result with pinned reference data generated by Tidy3D. The originating Tidy3D example is YJunction.ipynb, pinned at commit c37c785d52e9.

Technical schematic associated with Rectangular Y-junction power split vs Tidy3D

Integrated-photonics geometries covered by the benchmark suite.#

What is exercised#

3D strip Y at dl≈40nm (~0.2M voxels). Compare mode-power T1,T2,Tsum to Tidy3D. Rectangular junction approx. Asymmetry or low Tsum = geometry/mode bug to fix.

This case runs at its declared full benchmark resolution (resolution factor 1.0).

Recorded result#

Metric

Observed / error

Reference / limit

Error

Effective budget

Result

T1

0.202924

0.270472

0.0675476

0.147618

PASS

T2

0.261742

0.270474

0.00873133

0.147618

PASS

Tsum

0.464667

0.540946

0.0762789

0.208189

PASS

The table is rendered from progress.json; it is not a hand-written success claim. For metrics that report an error directly, the “observed” column repeats that error and the reference column is the acceptance threshold.

Reproduce#

uv run fdtdx-bench run --case parity_y_junction

Implementation and provenance: benchmarks/cases/parity_y_junction/case.yaml, benchmarks/cases/parity_y_junction/run.py, benchmarks/goldens/parity_y_junction.npz.

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