The present invention is a method and an apparatus for resonant coupling
in photonic crystal circuits. In one embodiment, a photonic crystal
device comprises a substrate having a plurality of apertures formed
therethrough, a photonic crystal circuit (e.g., formed by "removing" a
series of apertures), and a strip waveguide extending through the
apertures and coupled to the photonic crystal circuit via a surface
localized photonic state formed at a surface of the photonic crystal
(e.g., in the apertures). The surface localized photonic state
facilitates the efficient resonant tunneling of photons from the
wavelength-independent strip waveguide to the wavelength-selective
photonic crystal circuit, thereby improving the filtering capabilities of
the photonic crystal device.