Comparison of negative refractive index materials with circular, elliptical and rectangular holes

Negative-index metamaterials (NIMs) at near infrared wavelengths (similar to 2 mu m) are fabricated with circular, elliptical and rectangular holes penetrating through metal/ dielectric/metal films. All three NIM structures exhibit similar figures of merit; however, the transmission is higher for the NIM with rectangular holes as a result of an improved impedance match with the substrate-superstrate (air- glass) combination. (c) 2007 Optical Society of America.