Three-dimensional Anderson localization of light in dielectric disorder

Strong localization of light in three-dimensional disordered dielectric systems remains challenging to establish because it requires extremely strong recurrent scattering, while the long-lived localized contribution can be weak and masked by diffusive leakage or absorption in finite samples. Here we use large-scale time-domain simulations to solve the full-vector Maxwell problem and investigate dense random packings of high-index dielectric particles deep in the late-time regime. As the early diffusive component escapes, the transmitted signal develops a non-exponential tail and an effective diffusion coefficient that decreases toward localized scaling. The late-time spectra consist of narrow, well-separated resonances with sub-unity Thouless conductance and approximately Poissonian spacing statistics, indicating weak spectral overlap between long-lived modes. Simultaneously, the near field fragments into compact, non-propagating intensity clusters separated by persistent low-intensity channels. Cycle-averaged maps show that this dark-channel network remains correlated over many optical periods, revealing a quasi-stationary confinement pattern. Together, the dynamical, spectral and real-space signatures provide converging evidence for Anderson-localized vector electromagnetic modes in a disordered three-dimensional dielectric medium. This convergence shows localization as a self-organization of the late-time field into interference-separated, landscape-like modal basins.