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 ...

Students use mirror equations to determine the position and type. Students use mirror equations to determine the position, type, and size of mirror images for curved mirrors mathematically. Optical ...

Physicists in the US have demonstrated negative refraction at optical wavelengths for the first time. Vladimir Shalaev and colleagues at Purdue University obtained the result in a material consisting ...

The refractive index of a material defines the angle through which light is bent when it travels between a material and the vacuum. Ordinary materials such as glass have refractive indices between one ...