Non-quasi-static eigenstates of Maxwell's equations in a two-constituent composite medium and their application to a calculation of the local electric field of an oscillating dipole

摘要

In conventional optics the image is formed only by the propagating waves and the information encoded in the evanescent waves is lost, leading to limited resolution. A negative refractive index slab can amplify evanescent waves and enable the generation of an image by both propagating and non propagating waves, theoretically leading to unlimited resolution. Here we analyze the imaging of an oscillating dipole in a composite structure composed of an ε_1 slab surrounded by an ε_2 medium, where μ = 1 everywhere. For this purpose we calculate all the eigenstates and eigenvalues of the full Maxwell equations for the composite structure and develop an exact expansion for the local electric field E(r) in the system. Then we calculate the intensity and resolution for various permittivity values. We show that only the low order modes contribute to the expansion of the electric field which enables an efficient calculation of the physical quantities.