Abstract:
We consider the design and implementation of a two-dimensional metamaterial relay lens, conceptually formed by flattening a Maxwell fisheye lens-a perfect imaging device-through the use of a coordinate transformation. Because Maxwell's equations are form-invariant under coordinate transformations, the specifications for the constitutive parameters of the device are obtained immediately in a procedure that has now become known as transformation optics. To obtain a more favorable implementation of the lens, we seek a quasi-conformal transformation optics transformation that minimizes the required anisotropy, such that the resulting lens can be formed using isotropic, dielectric-only media. We demonstrate a flattened Maxwell lens at microwave frequencies using a nonresonant metamaterial and confirm its focusing and broad bandwidth behavior. Such planar, dielectric-only structures can be readily implemented in infrared and optical waveguides. © 2011 Optical Society of America.