Glossary
- Diffraction: divergent nature of a wave due to its limited size
- 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
- 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
- Diffraction angle: angle of a diffracted light ray with the normal to the diffracting surface
- Effective focal length: algebraic distance from the primary/secondary principal plane of an optical system to its front/back focal plane
- Optical system: in geometrical optics, assembly of optical components for redirecting the light in a controlled manner
- Back focal plane: plane conjugate by an optical system of an object plane perpendicular to the optical axis and located at infinity