Image quality deterioration due to phase fluctuation in layered superlens

Optical transfer function (OTF) and image spectrums of the layered metal (M)dielectric (D) superlenses (MD)n (where n is the number of cycles) are analyzed via transfer matrix method and effective-medium model. It is shown that the magnitude of OTF (MTF) with a high cutoff wave vector does not guarantee high resolution; the fluctuation of phase of OTF (PTF) is also a prime factor causing superlens imaging distortion. When the layered metaldielectric superlenses have a small number of cycles, we find that the different types of superlenses (such as (MD)nM, (MD)n, and (DM)nD) with the same effective permittivity have totally different performances; the superlens with (DM)nD arrangement has the best performance; this will be valuable for designing layered metaldielectric superlenses with less cycles.