Data and scripts for: Resolution limits of domain engineering for broadband quasi-phase-matching

Ensemble Monte Carlo data (2.25 x 10^6 synthesized domain patterns over 2250 parameter points) underlying Fig. 5 of the manuscript "Resolution limits of domain engineering for broadband quasi-phase-matching" (submitted to Physical Review Applied), together with the plane-wave eigenmode (MPB) calculation of the waveguide-mode effective-index offset, the figure-generation scripts (Figs. 1-5), and the numerical verification scripts. Files:- s4_all.csv: ensemble results, one row per parameter point (columns: sigma_nm, lc_um, dmin_nm, L_mm, lam_um, eta_rel_mean, eta_rel_std, fwhm_2pi_over_L, eq10_pred, nreal). Ensemble grid: 5 d_min x 10 sigma x 5 lc x 3 L x 3 Lambda = 2250 points, 1000 patterns each.- s4_fluct_mc.py: wall-by-wall pattern synthesis (grid snapping + Ornstein-Uhlenbeck fluctuation) and exact wall-integral form-factor evaluation.- s4_aggregate.py: aggregation into ensemble means.- s3_mpb_neff.py: MPB effective-index offsets for 45 TFLN ridge cross-sections.- make_figs_v3.py: generates Figs. 1-5.- verify_staircase_b7.py: 40-segment staircase vs continuous chirp check.- calc_v3_numbers.py: independent recalculation of quoted values.- README.md: full file descriptions and data dictionary. See README.md for details. Python 3.11+, numpy/matplotlib (meep/mpb only for s3_mpb_neff.py).