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 ...

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 ...

Based on highly accurate optical interferometry and fundamental quantum calculations, researchers in the US are developing an improved definition of the SI unit for pressure that will consign the ...