There are still no studies on whether MFEL can give a perfect imaging if a PPD is not exactly located at the image point or if a drain array is introduced.
The field distribution in a 2D MFEL for the case of an active drain in Leonhardt's analytical model (see Figures 4(a) and (b)) and that for the case of a PPD (see Figures 4(c) and (d)) located exactly at the image point are almost the same, which shows that we can use a PPD to mimic the drain in Leonhardt's analytical model.
SGW and MFEL are equivalent imaging systems from the perspective of transformation optics by a stereographic projection (i.e., the TE-polarized electric modes in an MFEL corresponds to the radial- polarized electric modes in an SGW).
Here [E.sub.z], H[rho], and [H.sub.[phi]] are fields for the TE mode in an MFEL with refraction index n = 2/(1 + [[rho].sup.2]); [E.sub.r], [H.sub.[theta]], and [H.sub.[phi]] are fields for the radial-polarized mode (i.e., the electric field contains only the radial component) in an SGW with refraction index n = 1/r.
The suggestion to justify the possibility of perfect focusing with such an unusual object like point drain initiated a set of critiques [10-14] which claim the super-resolving focusing developed in [4, 5] is merely a consequence of a special drain location, and not a fundamental property of MFEL. The most detailed one is the paper by Merlin .
The similar Green function for MFEL is obtained in the last section.