Glossary
- Diffraction: divergent nature of a wave due to its limited size
- Wavelength ( of a light wave ): distance between two consecutive identical states of the electric ( or magnetic ) field
- Angle of incidence: angle of a light ray incident on a surface with the normal to the surface
- Grating: optical device made of periodically spaced out diffractive elements
- Pitch ( grating ): distance between adjacent diffractive elements of a grating corresponding to the period of the diffracting pattern
- 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
- Divergence: defines the maximum angle between the light rays of a beam
- Resolvance (grating): ratio between the considered wavelength and the smallest resolvable wavelength variation ; two wavelengths are considered resolved if the distance between their diffraction peaks is at least equal to half the width of a diffraction peak