|Focus and Scope|
M. Giloan, R. Gutt and G. Saplacan
1. Company for Applied Informatics, Republicii nr. 107, 400489 Cluj-Napoca, Romania.
Abstract: Two transformation-optics inspired flat lenses are used to build up an optical system capable to transpose an area surrounding the object focal point in a magnified area surrounding the image focal point.
Transformation-optics approach enabled the design of anisotropic and inhomogeneous media, capable to manipulate wave paths and wave vectors [1-3]. Using specific coordinate transformations as proposed in , we design an optical imaging system based on two transformation-optics inspired flat lenses which provides sub-wavelength resolution. The key features of such a converging lens is that it provides a perfect convergence into its focal point of a light beam parallel to its optical axis and captures high spatial frequencies waves without converting them in evanescent waves.
A converging lens of thickness d and focal distance φ embedded in an isotropic and homogeneous medium having the same relative permittivity and permeability, ε=μ=m, is generated by the following transformation function z = h(x, y) z of the z-coordinate, with h(x, y) = m[δ−γ (φ2+x2+ y2 )1/2], where δ=1+φ/d and γ=1/d. The general outline of the transformed space is represented in Figure 1(a), in which the curved lines represent the transformed z-coordinate and the red area denotes a compression of the space with m = 4/3 and the blue area denote a dilation of the space for m = 1/3.