Architecture · Evidence
How ChipletOS Photonic Signoff works
Solver stack, AI surrogate roadmap, validation suite, and a candid map of what is not yet measured. The rigor-as-strength play: we tell you what is not yet measured, and we wire CI checks that detect drift on every commit.
Solver stack
Full-wave reference · cross-physics · closed-form analytical · coupled-mode · reference Neff
Full-wave reference solver
wired (process-isolated)Truth-grade FDTD
Process-isolated reference solver. Used to generate corpora and verify the AI surrogate. Never called in optimizer inner loops — lesson learned from the chiplet hot-path work.
Cross-physics solver
honest-skip when missingIndependent FDTD cross-check
Independent solver implementation. Powers the cross-solver agreement matrix. Skips cleanly when the binary is not on PATH.
Closed-form analytical model (waveguide)
liveHot-path analytical (waveguide)
Pure-Python closed-form effective-index for SOI strip waveguides. ~0.04 ms per call. Drives the inverse-design hot path.
Closed-form analytical model (MMI / taper)
scaffoldHot-path analytical (MMI / taper)
Closed-form eigenmode model for self-imaging MMIs and tapers. Pure-Python, sub-ms.
Coupled-mode analytical (ring / coupler)
scaffoldHot-path analytical (ring / coupler)
Coupled-mode model for directional couplers and ring resonators. Pure-Python, sub-ms.
Reference Neff solver
reference data onlyCross-check (Neff)
Truth-lane for SOI Neff comparisons in the published-paper cross-check.
AI surrogate roadmap
From today to higher-fidelity refresh
Today (v1)
DONEFoundation
Photonic tree scaffolded. Reference solver runner + closed-form analytical hot path live. 3 public Modal endpoints shipped.
Today (v1)
DONEAPI expansion
10+ /v1/photonics/* routes (3 public + 7+ auth-gated). Public predict-waveguide-mode, drc-photonic, validate-against-ieee. Auth-gated inverse design, Pareto, exporters.
On the roadmap
QUEUEDReference corpora + waveguide AI surrogate v1
Generate the waveguide reference corpus (target ~50K rows). Train the AI surrogate to R² ≥ 0.99 vs the reference solver. Wire the validation-suite check.
On the roadmap
PLANNEDMMI + MZI AI surrogates
Trained AI surrogate (MLP) for MMI and a sequence-aware surrogate for MZI spectrum output. Per-primitive reference corpora.
On the roadmap
PLANNEDRing + grating AI surrogates
AI surrogate for the resonant ring transfer function. Trained AI surrogate (MLP) for grating couplers. Per-primitive corpora.
Higher-fidelity refresh on the roadmap
PLANNEDPhotonic crystal + vendor exporters validated
Graph-based AI surrogate on lattice topology. Vendor-native validation of cross-EDA exporters (requires customer-side license).
Validation suite
Photonic validation-suite status
The photonic validation-suite checks plug into the same battery the chiplet stack runs on every commit. The design-rule check, the published-paper cross-check, and the adversarial robustness harness are live and passing; the AI-surrogate-R² check and the cross-solver agreement check honest-SKIP until the reference corpora land.
G18
Validation suite check passes (AI surrogate R² ≥ 0.99 vs reference solver)
Reference corpus not yet generated. Scaffolding lives in the validation suite and skips until the corpus and trained AI surrogate land.
G19
Design-rule check (live) — AIM-Photonics-class
Min waveguide width, bend-radius-vs-material, ring gap, grating pitch rules wired. Smoke geometry width=50 nm correctly flags the AIM min-width violation.
G20
Cross-solver agreement (on the roadmap)
Cross-solver matrix waits on reference corpus generation and cross-physics binary availability.
G21
Published-paper cross-check
Closed-form analytical stack run against published SOI Neff references. Pooled MAE within the analytical-model expected band vs published silicon-photonic references.
G22
Adversarial robustness harness
Mirrors the chiplet 100-geometry adversarial harness. Activates once the AI surrogate is in place.
What is not yet measured
Scope: gaps we publish alongside the wins
See Trust & Validation for the full validation-suite methodology and our published-paper cross-check numbers.
Reference corpora are not yet generated. Generating them is the prerequisite for AI surrogate v1, the validation-suite check, and the cross-solver agreement check.
Vendor-native validation of cross-EDA exporters is customer-deferred today (same workflow-lock posture as the 5/5 chiplet cross-EDA exporters). Higher-fidelity refresh on the roadmap ships the native-validation deferral docs.
The published-paper cross-check sits within the analytical-model expected band vs published silicon-photonic references. Closing the gap is the explicit purpose of the AI surrogate v1.
Photonic VNA wet-lab campaign is not yet RFQ'd — mirrors the chiplet $200-500K queue. Photonic measured-truth lane is the same gap the chiplet stack has.
Inspect the live signoff-health endpoint
One GET, no auth. Returns AI surrogate readiness, validation-suite status, and reference-solver availability.
GET /v1/photonics/signoff-health ↗