- 14.1 ENERGY LEVELS
- 14.2 OCCUPATION OF ENERGY LEVELS
- 14.3 INTERACTIONS OF PHOTONS WITH ATOMS
- 14.4 THERMAL LIGHT
- 14.5 LUMINESCENCE AND SCATTERING
Bohr and Einstein laid the theoretical foundations for describing the interaction of light with matter.
Light interacts with matter because matter contains electric charges. The time-varying electric field of light interacts with the electric charges and dipoles of atoms, molecules, and solids. A photon may interact with an atom (or ion) if its energy matches the difference between two atomic energy levels. The allowed energy levels and energy bands of matter are determined by the rules of quantum mechanics. If the atom is initially in the lower energy level, the photon ...