Glossary

Laser: acronym of : « light amplification by stimulated emission of radiation » ; device emitting spatially and temporally coherent light radiation based on the stimulated emission
Spectral width: difference between the largest and smallest wavelengths (frequencies) of the spectrum emitted by a light source, transmitted by an optical system or detected by a photodetector, etc.; the largest and smallest wavelengths (frequencies) are often defined at Full Width Half Maximum (FWHM)
Frequency: reverse value of the period
Mode lock: in a laser, longitudinal modes synchronization enabling short pulses emission