Various embodiments of the present invention are related to photonic systems and methods that can be used to encode data in carrier electromagnetic waves. In one embodiment of the present invention, a photonic system comprises a first waveguide configured to transmit a number of electromagnetic waves. The photonic system includes a photonic crystal with a resonant cavity and is configured to selectively and evanescently couple one or more of the electromagnetic waves from the first waveguide into the resonant cavity. The photonic system also includes a second waveguide positioned to transmit and extract one or more electromagnetic waves from the resonant cavity via evanescent coupling.