Optical surface Bloch modes of complete photonic bandgap materials as a basis of optical sensing.

Surface Bloch modes induced on three-dimensional dielectric photonic crystals with a complete photonic bandgap are evanescently decaying states at surfaces and have large field overlap with low-index media, resulting in narrow spectrum linewidth and simultaneously a large resonance shift due to a perturbation of the refractive index in the background media. Surface Bloch resonance states are analyzed for (001), (100), and (110) woodpile surface planes. Low-loss, high-sensitivity surface Bloch modes are also analyzed on a flat-top (001) woodpile planar surface. These analyzed surface Bloch modes are confined in a subwavelength scale and are expected to form a basis set used for optical resonance sensing.