Leaky waves in planar optical waveguides

The basic properties, applications and future potential uses of leaky waves in integrated optics are presented. It is first noted that, in addition to surface waves, the fields excited by realistic sources along thin films also include leaky waves. These fields can be described by inhomogeneous plane waves that bounce between the film boundaries and radiate energy into the exterior open regions. Leaky wave fields on multilayered and periodic media are examined and their role in beam and waveguide couplers is discussed. Finally, the construction of structures having variable leakage is described and their capabilities in providing a wide range of beam transformations are outlined.