Optical Properties Of Solids -

When a solid absorbs energy and re-emits it as light (e.g., LED lights).

At its core, the response of a solid to light is determined by its ( ) and its dielectric function ( Optical Properties of Solids

): Determines the speed of light in the material and how much it "bends" (refraction). Extinction Coefficient ( When a solid absorbs energy and re-emits it as light (e

The most critical factor in a solid's optical behavior is its . Insulators and Semiconductors: These have a "band gap" ( Egcap E sub g ). If a photon's energy ( ) is greater than Egcap E sub g Insulators and Semiconductors: These have a "band gap"

Anti-reflective coatings on glasses use thin-film interference to "cancel" reflected light.

In the infrared range, light interacts directly with the vibrations of the crystal lattice (phonons). 5. Applications in Technology