  In this letter, we show how transformation optics makes it possible to design
what we call conjugate metamaterials. We show that these materials can also
serve as substrates for making a subwavelength-resolution lens. The so-called
"perfect lens", which is a lens that could focus all components of light
(including propagating and evanescent waves), can be regarded as a limiting
case, in which the respective conjugate metamaterials approach the
characteristics of left-handed metamaterials, which have a negative refractive
index.
