Laser-Induced Fluorescence

Laser induced fluorescence (LIF) is the technique in which the laser frequency v is tuned to match a transition of a group of atoms or molecules, whose energy difference is E 12by a relation hv=E 12(where h is the Planck’s constant), and the resultant fluorescence is observed. By the resonant nature of the excitation, the fluorescence intensity is many orders of magnitude larger than other sources of scattering, such as Rayleigh, Raman, or Thomson scattering, if the relevant number densities are the same order of magnitude. Therefore, the LIF technique is very selective of species to be detected, sensitive and/or yields high spatial and temporal resolution. In addition, because electric and magnetic fields affect E 12, the values of these field strength should, in principle, be obtainable using LIF.