Slow-light in a cage

Slow-light effect has potential for applications ranging from optical information processing to optical switching. It is well-known that material dispersion can induce slow-light near some resonances, such as electromagnetically induced transparency. Additionally, structural dispersion can also be applied to realize slow-light, e.g. photonic crystal waveguides (PhCWs). Here we study the Bloch modes of a silicon periodic waveguide with an ultra-large hollow-core. With three-dimensional fully-vectorial calculations, we successively find that the proposed periodic waveguide can support guided Bloch modes (below the air light line). Moreover, this cage waveguide is quite flexible for geometric tailoring of dispersion relation, and can be a promising device for integrated nanophotonics.