A composite evanescent waveguide can include a first structured dielectric
layer and a second dielectric material oriented adjacent one another to
form a wave propagation interface between the first structured dielectric
layer and second dielectric material. Each of the first structured
dielectric layer and second dielectric material are formed of materials
such that the wave propagation interface can be capable of propagating an
all-evanescent surface wave. The resulting propagating surface waves tend
to have low losses and can be suitable for optical communications,
surface analysis, sensors, and a variety of other applications.