Both patterned periodic or random structures can exhibit large slow down factors associated with
large field enhancements. These properties can be exploited to good effect for a variety of sensing functions.
We describe here some basic mechanisms responsible for these effects and discuss their use. Some
experimental results are reported using porous form-birefringent super-lattice structures which can be scaled
in size for use from microwave to optical frequencies.
Keywords: Periodic structures, field enhancement, slow light.
