Leaky-wave theory, techniques, and applications: From microwaves to visible frequencies

The theory of electromagnetic leaky waves can explain a variety of electromagnetic phenomena and scenarios, from microwave to visible frequencies. In the field of wave physics, the damping of harmonic oscillations in time and/or space is associated with losses in a dissipative system. Moreover, in open systems, oscillation energy gradually gets lost in the form of radiation toward the remote boundaries of an open region, reducing the amplitude of oscillations, even in a nondissipative system. This effect occurs with radioactive states in quantum mechanics, with damped resonances in open acoustic or electromagnetic cavities, and with leaky-waves in open waveguiding structures. The theory of electromagnetic leaky waves can explain a variety of electromagnetic phenomena and scenarios, from microwave to visible frequencies.