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 at Harvard’s John A. Paulson School of Engineering and Applied Sciences have announced the first on-chip metamaterial with a refractive index of zero — meaning the phase of light can ...

Physicists at Harvard University in the US have built a silicon waveguide that exhibits a refractive index of, or close to, zero when operating at near-infrared telecom wavelengths. The waveguide can ...