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 ...

THE experimental study of an ionized gas in presence of the magnetic field has recently acquired considerable importance in connexion with the ionosphere. Notable investigations have been made by ...

The Brix scale, derived from the refractive index of a solution at 20 degrees Celsius (68 Fahrenheit), is widely known. Originally, it was established by determining the weight percentage of sucrose ...

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 ...