Resonance-gated orbital-angular-momentum meta-cipher for hierarchical multidimensional optical image encryption

We propose a resonance-gated orbital-angular-momentum (OAM) meta-cipher for hierarchical multidimensional optical image encryption. The guided-mode resonance (GMR) provides narrow wavelength and angular selectivity, orthogonal polarization channels address independent carriers, and a matched OAM charge reconstructs each binary share. An exclusive-OR operation then combines four optically recovered shares to reveal the plaintext. A coupled-mode model integrated with scalar Fourier optics yields two wavelength groups centered at 1549.8 and 1552.4 nm with quality factors of 4200–5000, corresponding to linewidths of 0.31–0.37 nm. The 2.6 nm channel separation exceeds seven representative linewidths, while a polarization-leakage floor of 10 −4 corresponds to a 40 dB extinction ratio. The model further predicts an angular tolerance of approximately 2.2° for a half-linewidth detuning and high-fidelity reconstruction for the matched OAM states ℓ =±1 and ±2, whereas an incorrect wavelength, polarization, or OAM key suppresses or scrambles the recovered carrier. These results demonstrate a compact route toward spectrally selective, multidimensionally keyed optical information processing.