two-photon excitation
Excitation resulting from successive or simultaneous absorption of two photons by an atom or molecular entity. This term is used for successive absorption only if some of the @E02250@ of the first photon remains in the atom or molecular entity before absorption of the second photon. The simultaneous two-photon absorption can also be called @B00668@.
two-photon process
PAC, 1996, 68, 2223. (Glossary of terms used in photochemistry (IUPAC Recommendations 1996)) on page 2282 [Terms] [Paper]