Wave Engineering Laboratory, Department of Optics and Photonics, National Central University, Jhungli 320, Taiwan.
J Phys Condens Matter. 2011 Jan 26;23(3):035301. doi: 10.1088/0953-8984/23/3/035301. Epub 2010 Dec 21.
In this paper we study the characteristics of subwavelength imaging of a photonic crystal (PhC) superlens under the influence of source displacement. For square and triangular lattice photonic crystal lenses, we investigate the influence of changing the lateral position of a single point source on imaging uniformity and stability. We also study the effect of changing the geometrical center of a pair of sources on the resolution of the double image. Both properties are found to be sensitive to the displacement, which implies that a PhC slab cannot be treated seriously as a flat lens. We also show that by introducing material absorption into the dielectric cylinders of the PhC slab and widening the lateral width of the slab, the imaging uniformity and stability can be substantially improved. This study helps us to clarify the underlying mechanisms of some recently found phenomena concerning imaging instability.
在本文中，我们研究了在光源位移影响下光子晶体（PhC）超透镜的亚波长成像特性。对于正方形和三角形晶格光子晶体透镜，我们研究了改变单个点光源的横向位置对成像均匀性和稳定性的影响。我们还研究了改变一对光源的几何中心对双图像分辨率的影响。这两个性质都对位移很敏感，这意味着 PhC 平板不能被严重视为平面透镜。我们还表明，通过在 PhC 平板的介电圆柱中引入材料吸收并增加平板的横向宽度，可以大大提高成像的均匀性和稳定性。这项研究有助于我们澄清一些最近发现的关于成像不稳定性的现象的潜在机制。
