Dynamic optical response of a self-referenced multi-defect photonic crystal under modeled tear-film perturbations: a photonic modeling framework for ocular-surface analysis.

Abstract

A transfer-matrix framework is developed for dynamic optical fingerprinting of modeled tear-film perturbations using a thermally self-referenced multi-defect one-dimensional photonic crystal. Four coupled defect compartments represent aqueous-index variation, hydration-dependent optical-thickness change, mucin/inhomogeneity-associated loss, and lipid-composite evolution, while a sealed reference cavity compensates common-mode thermal drift. Time-dependent transmission spectra are analyzed using corrected defect-mode shifts and local peak-transmission changes. The resulting hybrid fingerprints distinguish stable-film-like, evaporation-dominant-like, aqueous-deficient-like, lipid-deficient-like, and mucin-instability-like scenarios. The minimum terminal uncertainty-normalized separation was 16.43, exceeding the prescribed threshold of 3, and remained above this threshold from t=0.4 s onward using a 0.10 s sampling interval. Monte Carlo analysis with 500 realizations yielded a terminal minimum separation of 17.19±2.35, with all realizations exceeding the threshold. Under the matched-model thermal-only blank, temperature calibration suppresses simulated thermal drift by 99.85%-99.98%. These results establish a numerically grounded self-referenced framework for analyzing time-varying tear-film-like perturbations.