Laser Induced Fluorescence Techniques

Abstract

Of all the applications that have arisen from the invention of the laser, laser induced fluorescence (LIF) has been one of the most fruitful. A relatively recent technique, LIF has proven itself to be an extremely valuable research tool. Many areas of atomic and molecular physics have utilized various forms of LIF spectroscopy. Radiative and collisional phenomena for a multitude of ions, atoms, and molecules have been successfully investigated [1]. Energy distributions and product species resulting from chemical reactions have been studied. It has found wide use in combustion studies. Medical and biological researchers are also utilizing LIF. LIF is exceedingly sensitive for species detection (fluorescence from a single ion has been seen.) Experiments previously thought to be unrealistically difficult are now routinely performed. Using LIF, extremely high spectral, temporal, and spatial resolution can be obtained. These properties are, of course, attributable to the laser itself and LIF takes full advantage of them. Most LIF techniques are non-intrusive and allow nearly ideal experiments to be performed. For example, an atom or molecule can be prepared in a selected pure quantum state with essentially a delta function pulse of radiation.