in silico
Phase 1 : In Silico Validation
- Objectif
- To rapidly falsify the core hypothesis that a second-order polynomial regression model, fitted to a Box-Behnken design, can predict wavefront error and MTF with sufficient accuracy (R² > 0.95, RMSE < 0.02) to enable a 20% yield improvement via tolerance reallocation, using only ray-tracing simulations.
- Coût estimé
- €500-2000
- Durée estimée
- 4-6 weeks
- Critères de réussite
- Regression model R² on validation set · ≥ 0.95 · (Compute R² = 1 - (SS_res / SS_tot) on 20 independent validation points)
- RMSE for MTF prediction · < 0.02 (on 0-1 scale) · (RMSE = sqrt(mean((MTF_pred - MTF_sim)^2)) over 20 validation points)
- Yield improvement after tolerance reallocation · ≥ 20 percentage points (e.g., from 60% to ≥80%) · (Monte Carlo yield with 10,000 samples, one-tailed z-test for proportions (H0: yield ≤60%, alpha=0.05))
- Variance reduction at robust design point · ≥ 30% reduction in wavefront error variance · (F-test for equality of variances (one-tailed, alpha=0.05) comparing 1,000 MC samples at original vs. robust nominal)
- On continue si
- All four success criteria are met (R²≥0.95, RMSE<0.02, yield improvement ≥20pp, variance reduction ≥30%).
- On arrête si
- Any criterion fails (e.g., R²<0.90, RMSE>0.03, yield improvement <10pp).
- On réoriente si
- R²≥0.90 but <0.95, or yield improvement 10-19pp: consider adding cubic terms or a different DoE (e.g., Central Composite Design) and re-running Phase 1.
- Risques
- Second-order polynomial model is insufficient (R² < 0.90) due to higher-order interactions or nonlinearities.Probabilité : mediumParade : Test a third-order model with selected three-way interactions (e.g., curvature×thickness×index) or use Gaussian Process Regression as a fallback.
- Simulation time for 46 DoE runs + 10,000 MC samples is excessive (>1 week).Probabilité : lowParade : Use Zemax’s “Quick Tolerance” mode or reduce MC samples to 1,000 for initial screening. Parallelize simulations using Python multiprocessing.
- Baseline yield is already >80%, leaving little room for improvement.Probabilité : mediumParade : If baseline yield >80%, tighten all tolerances by 20% to create a lower baseline (e.g., 50-60%) and then test reallocation.