Absolute left-handed behaviors in a triangular elliptical-rod photonic crystal

Abstract

In this paper we theoretically study the left-handed behaviors in a two-dimensional triangular photonic crystal made of elliptical rods in air. An absolute left-handed region is found in the second photonic band by using the plane wave expansion method to analyze the photonic band structure and equifrequency contours. Typical left-handed behaviors such as negative refraction, flat superlensing and plano-concave lensing are demonstrated by the finite-difference time-domain simulations. These behaviors are also compared with the quasi-negative refraction and the resulted focusing effects in a square-lattice two-dimensional photonic crystal.

Image resolution analysis of different super lenses

“…Another structure which was investigated is a triangular lattice PC slab with elliptical dielectric rods with r x =0.5a, r y =a and ε=14. [12]. Propagation of the TM mode in the structure and the light focusing has been demonstrated in Fig.…”

Multi-Beam Interference Advances and Applications: Nano-Electronics, Photonic Crystals, Metamaterials, Subwavelength Structures, Optical Trapping, and Biomedical Structures

“…In some cases, the motif geometry plays a significant role in the performance characteristics of a device fabricated using MBI. For example, the lattice point geometry has been shown to affect the photonic-bandgap characteristics in photonic crystals [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45], selective plasmonic excitation in plasmonic crystals [46], photonic crystal laser beam pattern [47] and polarization mode control [48], birefringence of photonic crystal fibers [49], cell behavior in tissue engineering [50], tuning of surface textures [51], magnetization switching in periodic magnetic arrays [52], and, negative refraction and superlensing in metamaterials [53,54]. Accordingly, several studies report analytical and computational methods to select individual beam parameters to change the motif orientation and shape [34,42,55,56] from hemispherical to hemielliptical [57]; circular to triangular [58]; as well as, general structures including micro-cavities, micro-bumps, and rectangular bumps [51].…”

Parametric constraints in multi-beam interference

“…Even though most MBI configurations are not easily reconfigured, they may all be designed to provide one of a wide range of periodicities and translational symmetries based on a fixed wavevector configuration. 42,43 Even if a particular plane-group symmetry is possible, it is not clear that sufficient contrast is attainable for optical lithography purposes. In this case, it is not clear that full patterning capability remains as constraints are placed on beam amplitudes and polarizations.…”