Concept of an optical leaky-wave antenna embedded in a Fabry-Pérot resonator

We investigate the radiation of an optical leaky-wave antenna embedded in a Fabry-Pérot resonator (FPR), resonating in the direction of the guided leaky wave. Leaky-wave radiation is achieved via the generation of a -1 Floquet harmonic in a dielectric waveguide due to the inclusion of a periodic set of perturbations. The FPR is formed by confining the dielectric waveguide and the leaky-wave section between two partially reflective mirrors. We report the design principles that are required to achieve a pencil beam at broadside as a superposition of leaky waves that travel inside the FPR in two opposite directions. We also investigate the tunability of the radiation by using semiconductor regions in the waveguide and thereby exciting and controlling excess carriers. We report simulation results related to a realistic design as a proof of the concept.