Broad angle negative refraction in lossless all dielectric or semiconductor based asymmetric anisotropic metamaterial. (20th November 2015)

• Record Type: Journal Article
• Authors: Sayem, Ayed Al; Mahdy, M R C; Rahman, Md Saifur
• Is Part Of: Journal of optics. Volume 18:Number 1(2016:Jan.)
• Publication Date: 2015-11-20
• Subjects: metamaterial -- all dielectric metamaterial -- negative refraction -- semiconductor material -- iso frequency; Optics -- Periodicals; 535.05
• DOI: 10.1088/2040-8978/18/1/015101
• Languages: English
• ISSNs: 2040-8978

Abstract

Abstract: In this article, it has been theoretically shown that broad angle negative refraction is possible with asymmetric anisotropic metamaterials (AAMs) constructed by only dielectrics or lossless semiconductors at the telecommunication and relative wavelength range. Though natural uniaxial materials can exhibit negative refraction, the maximum angle of negative refraction and critical incident angle lie in a very narrow range. This problem can be overcome by our proposed structure. In our structures, negative refraction originates from the highly asymmetric elliptical iso-frequency. This is artificially created by the rotated multilayer sub-wavelength dielectric or semiconductor stack, which acts as an effective AAM. This negative refraction is achieved without using any negative permittivity materials such as metals. As we are using simple dielectrics, fabrication of such structures would be less complex than that of the metal based metamaterials. By considering the time harmonic field incidence, negative refraction has been demonstrated for two dimensional bi-dielectric structures for TM polarization with realistic parameters. Our proposed ideas have been validated by the full wave simulations considering both the effective medium approach and realistic structure model. This device might find some important applications in photonics and optoelectronics.