Cold-start SiN atom-slot beta optimizer

Live research campaign — qualified_success_plateau

This page is regenerated only from atomic optimizer checkpoints. Geometry, field, beta, and pole metrics are paired to the same evaluated binary mask. The campaign began from neutral gray density; the shifted phase starts only from its independently retained clean pole.

two symmetries · 4× reduction one-sided right guide 500 nm atom clearance beta_escape LBFGS_PARETO_ESCAPE qualified_success_plateau

latest β79.86%bounded common outer ledger

best β81.33%physically accepted masks

robust βpendingminimum across η=0.45 / 0.50 / 0.55

tracked poleQ=206.98 at 782.50 nmfield / energy conservative fit

spectral conservation1.37%inner / outer mismatch

connected material99.6%solid reaching right guide

Literal device contract

The 780.24 nm z-oriented atom sits at the end of a 1 µm-wide air access slot. No SiN is permitted within 500 nm of it. A 400 nm-wide, 500 nm-thick SiN waveguide is fixed only on the right. Everything between the slot/clearance boundary and the terminal guide is a free 2-D topology mask extruded through one film. The right guide breaks x symmetry; only y and z are reduced, with parity (0, +1, -1).

The ordinary acquisition used a vacuum-normalized LDOS floor, a 50 nm-radius conic filter, robust projection, and differentiable material reachability. The literal Maxwell mask is never silently amputated. The final and shifted solves use an exactly binary forward mask at projection beta 96.

Pole-tracked beta continuation

The clean handoff pole is Q=162.14 at 781.47 nm. The shifted phase runs a 1.55 ps broadband pulse on every adjoint evaluation. Differentiable field and stored-energy fits follow the complex pole, and the real-frequency pulse DFT is recentered when the pole drifts. This is the time-domain pole-following counterpart of Shaker et al.’s eigenfrequency-shifted method, not a claim that FDTD contains their FDFD shift-invert eigensolver.

Beta uses one conserved channel decomposition: guided TM power plus -x, residual +x, ±y, and ±z power on the same outer box. It is bounded by construction. The shifted score is log(beta) and deliberately has no LDOS or atom-power retention floor; emission, Purcell, and guided Purcell remain visible diagnostics. A mode overlap exceeding the complete +x face, inner/outer mismatch above 12%, an unhealthy field/energy fit, or Q below 75% of the retained seed rejects the proposal and rolls back. The service continues indefinitely after accepted and rejected steps.

Pareto escape controller

The production controller keeps separate beta, Q, and guided-Purcell islands on the one GPU. An adjoint supplies a direction, while exact-binary forward-only candidates at controlled topology churn decide whether the L-BFGS curvature history is committed. Erosion, nominal, and dilation pole fits gate promotion into the robust shared archive. Migrated or exploratory masks that pass only one threshold are visibly marked provisional and cannot unlock the 90% beta constrained second stage. Structured, spatially correlated mutations are screened only when the archive stagnates; the best-beta mask is never overwritten by exploration.

Current checks

check	value
optimizer status	qualified_success_plateau
optimizer algorithm	lbfgs_pareto_escape
completed adjoint updates	165 ordinary + 23 accepted shifted, including 6 Pareto escape updates (11 new adjoints / 173 validation forwards)
active objective	beta_escape
robust / provisional archive entries	0 / 10
full / reduced grid	(360, 208, 80) / 4
guided port effective index	1.77701
latest gray fraction	0.00%
left slot clear	True
right guide present	True
disconnected solid pixels	51
latest dominant residual loss	±z
retained pole source update	163
last ordinary LDOS / vacuum	0.594
shifted pulse fit interval	0.200–1.420 ps

Last checkpoint update: 2026-08-23T00:15:35.530770+00:00.