Artificially structured graded index materials for designing of functional photonic elements

It is feasible to design a graded index medium if the parameters (structural and material) of the two or even three dimensional photonic crystals are appropriately reconfigured. These structures are known as graded index photonic crystals. By engineering the index gradient power along both the radial and axial directions, different effective index profiles can be attained. As a result, variety of light manipulations including focusing, guiding and mode converters can be achieved. The discrete optical elements with curved surfaces and small focusing power can be replaced by the counterpart of more compact and effective planar devices that are based on the graded index medium.