Frequency shift enhancement in linear chain of coupled resonators with time discontinuity in permittivity

Abstract

A frequency shift of an electromagnetic wave is attracting much interest as it has applications in wavelength demultiplexing systems, switchers and tunable filters. In practice, temporal changing of the material refractive index can be realized by varying an input signal in a nonlinear structure [1]; by voltage control [2]; by a focused laser beam as a local heat source [3] or else by a plasma injection [4].