title: Annular focusing lens based on transformation optics.
abstract: We propose and design a kind of annular focusing lens based on transformation optics. Based on the method of eigen-mode expansions, closed-form expressions are derived to analyze the proposed annular lens rigorously. We show that the annular lens has excellent focusing property. Even when a barrier (such as a conducting cylinder) exists in the center of the lens, the analytical results demonstrate that the waves are still guided to propagate smoothly and focused on a spot.
authors: Bai Bing
authors: BB
authors: Xu
authors: Wei Xiang
authors: WX
authors: Jiang
authors: Guan Xia
authors: GX
authors: Yu
authors: Tie Jun
authors: TJ
authors: Cui