---
title: One-sided SiN atom-hole temporal-to-pole optimizer
---

# One-sided SiN atom-hole temporal-to-pole optimizer

**Worker:** not active · **stage:** `pole_q_volume_constrained` ·
**status:** `paused_resumable_q1767_atom_volume_constrained` · **checkpoint age:** 4307.9 min

This paused campaign launches the fundamental TM-like mode of one positive-x
waveguide into an 8 µm × 8 µm, 300 nm-thick SiN design. A centered z-oriented
atom occupies an immutable one-micron through-slab air hole. The first 150 or
more raw Adam updates minimize the absolute vector temporal error; a
trustworthy Q≥100 then activates frequency-free, adaptive-trust L-BFGS-B on
the fitted pole lifetime. Its Q directions are projected against the atom-mode
volume gradient, and every accepted geometry must remain below the frozen
pre-Q volume ceiling. No filter, material projection, or binarization is active.

| quantity | current |
|---|---:|
| temporal Adam updates | 150 / at least 150 |
| pole accepted updates / trials | 211 / 348 |
| Q | **1767.37** |
| best trusted Q | 1767.37 |
| field / energy Q | 1768.15 / 1767.37 |
| Q-estimator ratio | 1.00044 |
| pole wavelength | 773.456 nm |
| source-center wavelength | 773.502 nm |
| field-monitor wavelength | **773.502 nm** |
| design-region slab thickness | **0.3 µm** |
| Stage-B thickness coordinate / range | **False** / 0.300–0.300 µm |
| physical mode volume | 1.94042 µm³ |
| normalized mode volume | 4.19363 (λ_pole/n_air)³ |
| Q / normalized atom volume | **—** |
| Purcell from Q/V | — |
| fitted atom-pole amplitude at source clear | **—** |
| absolute atom-trace peak / handoff | — |
| source spectral power at pole / actual carrier | — |
| reciprocal guided-Purcell proxy | **—** |
| guided-Purcell proxy / handoff | **—** |
| Stage-B volume treatment | **2.0675 µm³** |
| three-window V span | 0.000125812 |
| active Q/V run time / window | — / — ps |
| gradient backend / storage | **`unknown`** / unresolved |
| structural backend decision | `not recorded` |
| exact reversible PML tape size | — GB |
| frozen measured value+gradient speedup | —x |
| Q/V fit start / nominal lifetime per window | — ps / — τ_amplitude |
| precision-triggered tape growths | 0 |
| final ringdown field-power / energy fraction | — / — |
| finite-step adjoint direction verified | **False** |
| ideal temporal fidelity | 0.553248 |
| active objective / value | **log Q / normalized atom volume** / 7.47747 |
| stage plateau / reason | **False** / `collecting_optimizer_memory` |
| plateau samples / evidence window | 0 / 0 |
| objective slope / detectable slope | — / — |
| trust-floor restarts since progress | 0 / 2 |
| practical fixed-beta Q/V gain over one memory | —% / 1% limit |
| practical plateau samples / required | 0 / 11 |
| practical trust radius still expanding | False |
| healthy / cumulatively pruned curvature pairs | **0 / 0** |
| L-BFGS / current-gradient predicted-ascent ratio | **—** |
| replay-triggered curvature recoveries | 0 |
| maximum last density motion | 0.00029999 |
| trust radius | 0.00045 |
| binarity score (1 is binary) | **—** |
| trainable gray fraction (0.05<rho<0.95) | **—%** |
| archived tangent-stage Q/V floor | — |
| projection beta / eta | **— / 0.5** |
| fixed-beta accepted Q/V updates / transition | 0 / objective plateau |
| material parameterization | `unfiltered_direct_50nm_pixels` |
| hard atom access | **1.000 µm minimum air hole, immutable** |
| pixel / grid | 50 nm / [202, 95, 25] |
| non-PML z span / material-stack-to-PML air gap | 1.50 / 0.60 µm |
| z PML | 0.50 µm per side |
| z-padding convergence audit | `passed_keep_1p5um_interior` |
| 1.50→3.40 µm replay: residual / field-Q / energy-Q change | 7.5144e-05% / -0.004968% / -0.7036% |
| binarization / material projection / filter | **False / False / off** |
| physical waveguide escape eta | not part of the active objective |

## Q, V, objective, and optimizer history

![Q, V, objective, and motion](../_static/generated/atom_hole_temporal_q_history.png)

The Q axis is linear. A pole is not trusted until the centered
Ez and total
energy decay estimates agree. Mode volume uses the geometric mean of their
three same-pole windows and the
same fitted pole wavelength; the local permittivity is exactly air by the hard
geometry constraint. The rejected Q-only branch reached Q=3,619 while normalized V deteriorated to
17.85; it is archived and is not part of this curve.





## Ideal and measured atom response

![Ideal and measured temporal response](../_static/generated/atom_hole_temporal_q_response.png)

The target has fixed amplitude and phase for Q=10,000, beta one, V=0.1 µm³,
and perfect Ez-polarized overlap. It is not rescaled
to fit the simulation.

## Geometry and fields

![Initial, current, and difference geometry](../_static/generated/atom_hole_temporal_q_geometry.png)

![Ez field profiles](../_static/generated/atom_hole_temporal_q_fields.png)



{download}`Exact campaign methodology <../_static/downloads/atom_hole/METHOD.md>`