RCWA Backend Parity Report
Generated on 2026-11-02 from the real PixelStack -> RCWA adapter path.
This report runs a small 1.0 um BSI PixelStack through each RCWA backend adapter with the same TE source and wavelength list. It is a backend-health gate, not a converged optical benchmark: the Fourier orders are deliberately small so adapter failures and normalization mismatches are visible quickly.
Executive summary
- 4 of 4 RCWA adapters produced bounded, energy-consistent R/T/A values in this smoke test.
- 2 of 4 adapters met the parity target against
torcwa(max R/T/A delta <= 0.05). - Production pixel comparisons require converged R/T/A and independently validated photodiode QE. Passing this low-order health gate establishes neither condition.
Low-order smoke test
This report does not claim converged QE. It checks whether adapters can run the same patterned stack and return plausible R/T/A numbers. Converged solver settings belong in the convergence report.
R/T/A spectra
Health and runtime
Backend table
| Backend | physical ok | parity ok | R@550 | T@550 | A@550 | mean QE@550 | energy residual | max delta vs torcwa | runtime s | first warning/error |
|---|---|---|---|---|---|---|---|---|---|---|
| torcwa | yes | yes | 0.0342 | 0.0007 | 0.9652 | 0.0057 | 0 | 0 | 0.6604 | - |
| grcwa | yes | yes | 0.0342 | 0.0007 | 0.9652 | 0.8958 | 0 | 1.73e-07 | 0.0545 | - |
| meent/numpy | yes | no | 0.0076 | 0.0026 | 0.9898 | 0.9059 | 0 | 0.0525 | 1.3291 | - |
| fmmax | yes | no | 0.0195 | 0.0118 | 0.9687 | 0.8973 | 0 | 0.0504 | 66.5784 | - |
Interpretation
physical okmeans finite, bounded R/T/A values and |R+T+A-1| <= 0.05.parity okmeans physical output and max R/T/A delta againsttorcwa<= 0.05.mean QEis the adapter's photodiode-allocation proxy averaged over the four Bayer pixels. It is useful for detecting broken absorption allocation, not for design decisions at this low order.- A backend can import successfully but still fail this report if the adapter uses stale upstream APIs or incompatible normalization.
Regeneration
powershell
uv run python scripts\generate_rcwa_backend_parity_report.pyGenerated metrics are stored at docs/public/reports/rcwa-backend-parity/rcwa_backend_parity_metrics.json.