Glossary
- Diffraction: divergent nature of a wave due to its limited size
- Grating: optical device made of periodically spaced out diffractive elements
- Wavelength ( of a light wave ): distance between two consecutive identical states of the electric ( or magnetic ) field
- Diffraction order: for a diffraction grating or an acousto optic crystal and a given monochromatic plane light wave, defines the difference between the optical paths expressed in wavelength unit and traveled by light rays diffracted by two consecutive diffractive elements ; also defines the directions along which the diffracted wave may propagate
- Free spectral range ( grating ): maximum spectral width making it possible to avoid the overlap of a diffraction order with its neighbors