Two flashlamp-pumped, tunable, dye lasers have been utilized to study three-photon ionization in atomic sodium. The resulting ion yield shows large peaks at laser frequencies which correspond to electric quadrupole transitions. This is the first direct observation of electric quadrupole effects in multiphoton ionization. The $3p^{2}P_{\frac{3}{2}}\ensuremath{\rightarrow}4f$ matrix element is determined, and the fine-structure splitting of the $5p$ state is measured.Two flashlamp-pumped, tunable, dye lasers have been utilized to study three-photon ionization in atomic sodium. The resulting ion yield shows large peaks at laser frequencies which correspond to electric quadrupole transitions. This is the first direct observation of electric quadrupole effects in multiphoton ionization. The $3p^{2}P_{\frac{3}{2}}\ensuremath{\rightarrow}4f$ matrix element is determined, and the fine-structure splitting of the $5p$ state is measured.

Physical Review LettersJul 21, 197541 citations

Photon Statistics, Instabilities and Phase Transitions in Dye Lasers

C. R. Willis

Springer eBooksJan 1, 19781 citation

5p

state is measured.