https://doi.org/10.1351/goldbook.B00668
Simultaneous (coherent) @[email protected] of two @[email protected] (either same or different @[email protected]), the energy of excitation being the sum of the energies of the two photons. Also called @[email protected]
Note:
This term is sometimes also used for a two-step absorption.
This term is sometimes also used for a two-step absorption.