A property of a material that changes the speed of light, computed as the ratio of the speed of light in a vacuum to the speed of light through the material. When light travels at an angle between two ...

Researchers in Korea have created a new metamaterial with the most extreme positive index of refraction yet – a whopping 38.6. The metamaterial operates at terahertz frequencies and the team believes ...

When a ray of light is incident at normal incidence, (at right angles), to the surface between two optical materials, the ray travels in a straight line. When the ray is incident at any other angle, ...

Recent experiments that demonstrate the negative refraction of light could bring a heated scientific debate to a close, and give negative-index materials a positive future Figure 1: Negative-index ...