Glossary

Lambertian light source: light source with a constant radiance (or luminance) whichever the direction
Multimode fiber optic: fiber optic enabling the propagation of several transverse modes
Effective focal length: algebraic distance from the primary/secondary principal plane of an optical system to its front/back focal plane
Lens: optical component with two refractive surfaces axially symmetrical for redirecting the light in a controlled manner
Transverse magnification: size ratio of an image and an object, the image being conjugated to the object by an optical system; for centered optical systems, the transverse magnification is defined with objects in a plane perpendicular to the optical axis - transverse magnification is then positive if object and image have the same orientation and negative otherwise
Core: central part of a fiber optic in which lightwaves are guided
Fiber optic: long cylindrical optical component guiding light
Numerical aperture ( fiber optics ): dimensionless number characterizing the acceptance cone angle of an optical fiber
Clear aperture: aperture diameter of an optical system
Coupling efficiency ( fiber optics ): ratio between the optical power emitted by a source and the optical power effectively injected in a fiber optics