# Live quasi-2D SiN remote-atom optimizer

<div class="validation-badge">optimization paused at user request</div>
<div class="validation-badge">latest evaluation 40 accepted</div>
<div class="validation-badge">cold start · no silicon controls transferred</div>
<div class="validation-badge">single-etch 2-D mask extruded through 240.6 nm SiN</div>

Last rendered **2026-08-22 10:29:25 UTC** from `benchmarks/artifacts/invdes_sin_quasi2d_remote_atom_ldos_live_v1.npz`. The checkpoint
was paused after **41** differentiable evaluations. Evaluation 40 is the last
complete accepted checkpoint; the interrupted evaluation was not committed.
This page deliberately distinguishes the training fit from the final long-run
validation.

| Quantity | Current evidence |
|---|---:|
| Maximum accepted shifted LDOS | **11.413× vacuum** |
| Maximum-LDOS row Q | 55584.5 |
| Maximum-LDOS row wavelength | 780.132 nm |
| Score-trusted shifted LDOS | 11.413× vacuum |
| Score-trusted Q | 55584.5 |
| Score-trusted wavelength | 780.132 nm |
| Latest shifted LDOS | 11.36× vacuum |
| Latest Q | 58227 |
| Latest wavelength | 780.14 nm |
| Accepted / evaluated | 33 / 41 |
| Adaptive trust-step scale | 0.134× |
| Atom-to-nearest-SiN distance | 500.000 nm |
| Independent controls | 379 |
| Full grid / retained symmetry | (464, 156, 64) / x,z (4×) |

## Literal quasi-2D geometry

```{figure} ../_static/generated/sin_quasi2d_ldos_geometry.png
:alt: Seven-row quasi-2D SiN photonic crystal with curved edge and remote atom
:width: 100%

The plotted mask is the latest actual hard forward geometry, whether accepted
or rejected; the badge and title state which. It has seven triangular-
lattice rows and a curved lower boundary; it is not a nanobeam. All holes and
the bulge are optimized in x-y and then extruded through one uniform slab.
```

## LDOS, Q, and pole tracking

```{figure} ../_static/generated/sin_quasi2d_ldos_progress.png
:alt: Remote atom LDOS, Q, and resonance wavelength by gradient evaluation
:width: 100%

Rejected trust-region trials remain visible. The green band is ±1% around the
780.24 nm atomic transition; the dashed LDOS line is the training threshold,
not yet the final claim.
```

## Latest Ey field

```{figure} ../_static/generated/sin_quasi2d_ldos_field.png
:alt: Latest Ey field over the quasi-2D SiN geometry
:width: 100%

White contours are the literal SiN-air boundary and the star is the remote Ey
dipole. The full x plane is reconstructed only for display from the exact x
mirror reduction used by FDTD.
```

## Acceptance contract

The optimizer may hand off only after its clean tracked pole has LDOS ≥20 and
lies within 1% of 780.24 nm. Completion additionally requires a fresh longer
remote-dipole forward solve, multi-pole harmonic inversion, a matched vacuum
normalization, and a finer-grid geometry/field audit. Until those checks pass,
the values above are optimizer evidence rather than a completed-device claim.

## Independent validation


No independent validation artifact exists yet. The optimizer must first reach
its training handoff gate.


The final executed notebook will be generated only after this independent audit passes.

The cold seed was a dimensionlessly scaled Zhang-style curved-mirror cavity in
suspended SiN (`n=2.05`), not a prior
optimized silicon design. Its independent atom-source reconstruction found
LDOS 2.619, Q 5,362, and a 781.33 nm pole before the first gradient.