Imaging by flat lens using negative refraction

Subwavelength imaging by a flat cylindrical lens using optimized negative refraction

Metal-free flat lens using negative refraction by nonlinear four-wave mixing.

A perfect lens with unlimited resolution has always posed a challenge to both theoretical and experimental physicists. Recent developments in optical metamaterials promise an attractive approach towards perfect lenses using negative refraction to overcome the diffraction limit, improving resolution. However, those artificially engineered metamaterials are usually accompanied by high losses from...

Sound focusing by flat acoustic lenses without negative refraction

We present the experimental realization of two flat acoustic lenses generated by inverse design. The lenses consist of aperiodic lattices of aluminum cylinders confined in a rectangular area. They were obtained by a design tool that combines multiple scattering theory and a genetic algorithm. The cylinders’ positions are optimized by the genetic algorithm in order to produce maximum sound ampli...

Negative refraction makes a perfect lens

With a conventional lens sharpness of the image is always limited by the wavelength of light. An unconventional alternative to a lens, a slab of negative refractive index material, has the power to focus all Fourier components of a 2D image, even those that do not propagate in a radiative manner. Such "superlenses" can be realized in the microwave band with current technology. Our simulations s...

Does negative refraction make a perfect lens?

Article history: Received 22 August 2008 Accepted 1 September 2008 Communicated by V.M. Agranovich PACS: 78.20.Ci 42.30.Wb 73.20.Mf