Resonance Enhanced Multi-Photon Ionization (REMPI) is a technique applied to the
spectroscopy of
atoms and small
molecules. In practice, a tunable
laser can be used to access an
excited intermediate state. The
selection rules associated with a two-
photon or other multi-photon
photoabsorption are different from the selection rules for a single photon transition. The REMPI technique typically involves a resonant single or multiple photon absorption to an electronically excited intermediate state followed by another photon which
ionizes the atom or molecule. The light intensity to achieve a typical multiphoton transition is generally significantly larger than the light intensity to achieve a single photon photoabsorption. Because of this, a subsequent photoabsorption is often very likely. An ion and a free electron will result if the photons have imparted enough energy to exceed the ionization threshold energy of the system. In many cases, REMPI provides spectroscopic information that can be unavailable to
single photon spectroscopic methods, for example
rotational structure in molecules is easily seen with this technique.
See more at Wikipedia.org...
Rempi is a Hanseman language spoken in Papua New Guinea.
The language is: Rempi
Free Download Now!
