Influence of source displacement on the features of subwavelength imaging of a photonic crystal slab

• Published in: Journal of physics. Condensed matter 2011-01, Vol.23 (3), p.035301-5
• Main Authors: Luan, Pi-Gang, Chiang, Chen-Yu, Yeh, Hsiao-Yu
• Format: Article
• Language: English
• Subjects: Condensed matter; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Imaging; Lenses; Optical materials; Optics; Photonic bandgap materials; Photonic crystals; Physics; Pollution sources; Slabs; Stability; Variability
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/23/3/035301

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.