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title: Adaptive nanobeam waveform frontier
---

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# Adaptive nanobeam waveform frontier

<div class="live-banner"><span class="live-dot is-paused"></span>
<strong>PAUSED</strong> · one design on one GPU · exact replay after every proposal · refreshed every 60 s</div>

The former Q≈30,000 stop was an **objective/controller plateau, not a physical ceiling**.
The old scalar had turned off Q pressure while 87.0% of its remaining loss came from an
already-passing spatial match. The replacement keeps a carrier-transported temporal target
at twice the measured Q, advances it automatically, and treats loading, mode identity, and
frequency as buffered constraints.

| Live quantity | Current state |
|---|---:|
| Controller | **running** · adaptive carrier-transported Q waveform |
| Numerical checkpoint | **9** · 2026-09-05T14:25:46.606972Z |
| Accepted / attempted | **9 / 9** |
| Carrier-tracked short-tape Q | **41280.3** |
| Best exact-replay feasible Q | **41280.3** |
| Adaptive Q target / re-anchor point | **81998.7 / 73798.8** |
| Wavelength / drift | **1551.870 nm / -11.002 nm** |
| Reciprocal loading / hard-floor margin | **0.268800 / 7.63%** |
| Self-referenced mode mismatch / gate | **0.000019 / 0.250** |
| Decoded trust radius / last material motion | **0.0009999 / 0.0009999** |

```{figure} ../_static/generated/nanobeam_waveform_scratch_geometry.png
:alt: Frozen plateau, current adaptive frontier, and best feasible nanobeam topologies

Yellow is material density, not optical intensity. The hollow cyan symbols mark the elevated
air dipole and do not add material. The center remains trainable.
```

```{figure} ../_static/generated/nanobeam_waveform_frontier_progress.png
:alt: Live adaptive Q target, waveform merit, loading, wavelength, and spatial constraints

Waveform merits are split at every target/phase epoch, because scores from different moving
targets are not directly comparable.
```

```{figure} ../_static/generated/nanobeam_waveform_scratch_fields.png
:alt: Checkpoint-labelled same-lineage nanobeam field replay or an explicit withheld placeholder

Same-lineage forward field from checkpoint **9**; lag **0** checkpoint(s).
The service serializes this forward replay between five-step optimizer chunks, so field capture
never competes with an adjoint solve for GPU memory.
```

```{figure} ../_static/generated/nanobeam_waveform_scratch_response.png
:alt: Measured detector trace and carrier-profiled desired temporal waveform

The trace uses the same checkpoint provenance as the field panel.
```

## What caused the plateau

- The one-sided Q=30,000 waveform target was already saturated: its contribution was only
  **0.12%** of the final loss and the total-gradient cosine with direct log-Q was **−0.0158**.
- Exact higher-target replays raised Q at every tested material radius; the largest one-step
  test gained about **782 Q** while loading changed by only **−0.000146**.
- Repeated unchanged forwards were bit-identical, excluding carrier-fit noise at this state.
- The old random escapes moved material 49–490× farther than productive local steps and its
  escape counter was not reset by later progress.

The current controller does not know the reference optimum. It re-anchors at 90% of a target
that is always twice its own measured Q. Frequency is unpenalized over the inner 36 nm-wide
window; only a smooth warning near the ±20 nm branch boundary acts on it.

## Qualification remains pending

The values above come from the differentiable 0.8 ps optimization tape. Final success still
requires a fresh independent 3 ps replay with Q≥**130,767.7**, conservative
Q≥**122,324.0**, reciprocal loading≥**0.249708**,
and mode volume≤**0.047055 µm³**. No short-tape value is silently called final.

Last dashboard render: **2026-09-05 14:30:57 UTC**.