Negative refraction in a photonic crystal with a metallic cross lattice basis

Abstract

A metamaterial with a negative effective index of refraction is made from a two-dimensional square lattice photonic crystal with a metallic cross lattice basis. A simple procedure is given to design a negative index band within a desired frequency range. The operating frequency is made sufficiently low so as to avoid high orders of diffraction from a slab. An effective index of −1, which is a requirement for perfect lensing, is designed. In addition, the structure is optimized to exhibit the largest possible bandwidth of negative refraction, while ensuring an isotropic response and efficient coupling from free space. Simulation results show negative refraction of a Gaussian beam through a prism of such a metamaterial. The simplicity and versatility of the structure make it a suitable candidate for frequencies into the infrared region. The dispersive nature of the metallic crosses and planar fabrication are also discussed.

Positive, negative, zero refraction, and beam splitting in a solid/air phononic crystal: Theoretical and experimental study

“…[17][18][19][20][23][24][25] The use of EFSs in an extended zone scheme allows one to see all of the possibly excited Bloch modes within the crystal. This scheme has also provided a means of explaining observed beam splitting in certain systems, [26][27][28] which can be attributed to multiple Bloch modes satisfying phase-matching conditions and leading to higher orders of refraction. The demonstration of a system which exhibits all of these characteristics ͑positive, negative, and zero refraction, as well as beam splitting͒ is highly dependent on various features of the corresponding equifrequency surfaces ͑EFSs͒ of the crystal.…”

Coated nonmagnetic spheres with a negative index of refraction at infrared frequencies

“…Photonic crystals can have a negative effective index, although the mechanism responsible for the effect is different, and as such they are more prone to practical problems. 8,9 We are interested in developing negative index metamaterials at infrared and optical frequencies. To this end, we have previously reported that a three-dimensional array of dielectric spheres can be made to exhibit an isotropic negative permeability.…”

“…To this end, we have previously reported that a three-dimensional array of dielectric spheres can be made to exhibit an isotropic negative permeability. 10,11 The background theory of the effective permittivity and permeability of dielectric and magnetic spheres was first reported by Lewin. 12 Other reports have also found a negative permeability or negative index by using magnetodielectric 13 or ferroelectric 14 spheres.…”

Liquid crystal cladded metallo-dielectric and all-dielectric frequency selective surfaces for broadband tunable optical filters and planar negative index optics

“…In recent years, much research has gone into the study of optical metamaterials [1][2][3][4][5][6][7][8][9][10][11][12][13]. These are periodic or quasi-periodic assemblies of materials with dissimilar optical properties (complex permittivity and/or complex permeability) for which radiation of wavelength greater than the period of the metamaterial cells experience an effective permittivity and permeability, i.e.…”

“…an effective refractive index, not possessed by the original constituents. Structures that have been studied include photonic crystals [6,7,13], loaded transmission line media [8,9], polaritonic resonances in nano-size spheres and cylinders [5,10,11], and frequency selective surfaces (FSSs) [4,12]. Frequency selective surfaces are 2D periodic arrays of cells, where each cell consists of metallic patches or apertures (in metallo-dielectric FSSs) or in a patterned configuration of two dielectrics with different optical properties (in the case of all-dielectric FSSs) [14].…”