6. Glossary – Definitions

LASER (Light Amplification by Stimulated Emission of Radiation)

This term was originally used to distinguish MASER (Microwave Amplification of Stimulated Emission of Radiation), and now covers all types of coherent light amplification, regardless of the wavelength range involved, from X-rays to infrared (including UV, visible, near- and mid-infrared and terahertz).

Quantum-dots

2-10 nm nanocrystals composed of a few 10 ⁴ to 10 ⁵ binary semiconductors (e.g. ZnS, CdSe) arranged in crystalline order. Their light excitation leads to the creation of electron-hole pairs (excitons) with the quantum characteristics of a hydrogen atom with a very large Bohr radius (5.6 nm for CdSe, for example). Electron-hole recombination then leads...