Embedded Photonic Eigenvalues in 3D Nanostructures

Confinement of light is usually achieved by reducing the photonic density of states of the surrounding environment, as in waveguides and photonic crystal cavities. In contrast, optical bound states have been recently shown to exist within the radiation continuum in large periodic arrays, in analogy with embedded eigenvalues in certain quantum systems. Here we demonstrate that under special conditions it may be possible to induce three-dimensional photonic embedded eigenvalues in a subwavelength open scattering system. The striking properties of these optical states without radiation loss may lead to unprecedented light localization in nanophotonic structures.