Electromagnetic wave manipulation using layered systems
  We show that the optical properties of an oblique layered system with two kinds of isotropic materials can be described using the concept of transformation media as long as the thickness of the layers is much smaller than the wavelength. Once the connection with transformation media is established, we then show that oblique layered system can serve as a universal element to build a variety of interesting functional optical components such as wave splitters, wave combiners, one-dimensional cloaking devices and reflectionless field rotators. 
Huanyang Chen and C. T. Chan