Analytical study of subwavelength imaging by uniaxial epsilon-near-zero metamaterial slabs

We discuss the imaging properties of uniaxial epsilon-near-zero metamaterial slabs with possibly tilted optical axis, analyzing their subwavelength focusing properties as a function of the design parameters. We derive in closed analytical form the associated two-dimensional Green's function in terms of special cylindrical functions. For the near-field parameter ranges of interest, we are also able to derive a small-argument approximation in terms of simpler analytical functions. Our results, validated and calibrated against a full-wave reference solution, expand the analytical tools available for computationally efficient and physically incisive modeling and design of metamaterial-based subwavelength imaging systems. Comments Giuseppe Castaldi, Silvio Savoia, Vincenzo Galdi, Andrea Alù, & Nader Engheta. (2012). Analytical study of subwavelength imaging by uniaxial epsilon-near-zero metamaterial slabs. Physical Review B, 86(11), 115123. doi: 10.1103/PhysRevB.86.115123 ©2012 American Physical Society This journal article is available at ScholarlyCommons: http://repository.upenn.edu/ese_papers/633 PHYSICAL REVIEW B 86, 115123 (2012) Analytical study of subwavelength imaging by uniaxial epsilon-near-zero metamaterial slabs Giuseppe Castaldi, Silvio Savoia, and Vincenzo Galdi* Waves Group, Department of Engineering, University of Sannio, I-82100 Benevento, Italy Andrea Alù Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712, USA Nader Engheta Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA (Received 8 May 2012; revised manuscript received 29 August 2012; published 17 September 2012) We discuss the imaging properties of uniaxial epsilon-near-zero metamaterial slabs with possibly tilted optical axis, analyzing their subwavelength focusing properties as a function of the design parameters. We derive in closed analytical form the associated two-dimensional Green’s function in terms of special cylindrical functions. For the near-field parameter ranges of interest, we are also able to derive a small-argument approximation in terms of simpler analytical functions. Our results, validated and calibrated against a full-wave reference solution, expand the analytical tools available for computationally efficient and physically incisive modeling and design of metamaterial-based subwavelength imaging systems. DOI: 10.1103/PhysRevB.86.115123 PACS number(s): 78.67.Pt, 78.20.Ci, 41.20.Jb, 42.30.Wb