We propose a new metamaterial with a gradient negative index of refraction, which can focus a collimated beam of light coming from a distant object. A slab of the negative refractive index metamaterial has a focal length that can be tuned by changing the gradient of the negative refractive index. A thin metal film pierced with holes of appropriate size or spacing between them can be used as a metamaterial with the gradient negative index of refraction. We use finite-difference time-domain calculations to show the focusing of a plane electromagnetic wave passing through a system of equidistantly spaced holes in a metal slab with decreasing diameters toward the edges of the slab.
© 2007 Optical Society of America
Original Manuscript: January 19, 2007
Revised Manuscript: July 2, 2007
Manuscript Accepted: July 5, 2007
Published: September 6, 2007
Photonic Metamaterials (2007) JOSA A
Anatoliy O. Pinchuk and George C. Schatz, "Metamaterials with gradient negative index of refraction," J. Opt. Soc. Am. A 24, A39-A44 (2007)