Gradient-index electron optics in graphene p−n junctions

Electron optics in graphene

In ballistic graphene, electrons behave in many ways similar to photons. By changing the electrostatic potential locally, we realized elements in graphene that are known from optics. But in contrast to conventional optics, gapless p-n interfaces can be formed showing a negative index of refraction and the effect of Klein tunneling. Even more, electron trajectories can be bent by applying a magn...

Thomas Young's investigations in gradient-index optics.

PURPOSE James Clerk Maxwell is usually recognized as being the first, in 1854, to consider using inhomogeneous media in optical systems. However, some 50 years earlier, Thomas Young, stimulated by his interest in the optics of the eye and accommodation, had already modeled some applications of gradient-index optics. These applications included using an axial gradient to provide spherical aberra...

Porous Silicon Gradient Refractive Index Micro-Optics.

The emergence and growth of transformation optics over the past decade has revitalized interest in how a gradient refractive index (GRIN) can be used to control light propagation. Two-dimensional demonstrations with lithographically defined silicon (Si) have displayed the power of GRIN optics and also represent a promising opportunity for integrating compact optical elements within Si photonic ...

Three-dimensional Gradient Index Optics Fabricated in Diffusive Photopolymers

Transformation Optics Techniques for Designing Gradient Index Devices