Anomalous depolarization of the5p2P3/2→8p

Abstract

Measurements of the linear polarization degree of the 5p 2 P 3/2 →8p 2 P j Ј transitions ( jЈϭ1/2,3/2) in atomic 87 Rb are reported. The radiative transitions are electric-dipole forbidden, but electric-quadrupole allowed. In addition, because of the relatively strong spin-orbit interaction in Rb, the p-p transitions can acquire a magnetic-dipole transition strength that may be a measurable fraction of the electric-quadrupole strength. The polarization measurements can generally provide a different and sensitive way to extract the relative transition strengths. We have measured the linear polarization degree of the 5p 2 P 3/2 →8p 2 P j Ј transitions over a wide range of Rb density. We report here observations of a different depolarization effect, whereby the measured polarization of the 5s 2 S 1/2 →5p 2 P 3/2 →8p 2 P 1/2 transition increases, while that for the 5s 2 S 1/2 →5p 2 P 3/2 →8p 2 P 3/2 transition decreases with increasing Rb density. The behavior is attributed to strong laser field effects associated with the 5s 2 S 1/2 →5p 2 P 3/2 resonance transition.

Observation of the5p3/2→6p3/2electric-dipole-forbidden transition in atomic rubidium using optical-optical double-resonance spectroscopy

“…The coherent mixing of waves is theoretically studied in [9] for n 1 2 P − n 2 2 P transitions. The excitation of the 5p → 8p forbidden transition in thermal rubidium atoms was produced with a pulsed laser in [10] and using cold atoms in [12]. The experiment with cold atoms [12] allowed resolution of the atomic hyperfine structure and conclusively determined that there was no magnetic dipole contribution to this transition.…”

“…Also, the study of strongly forbidden J = 0 → J = 0 transitions via single-photon excitation is presented in [8]. Excitation of forbidden transitions involving states with nonzero angular momentum in alkali atoms have also been studied over the last few years [9][10][11][12][13]. The coherent mixing of waves is theoretically studied in [9] for n 1 2 P − n 2 2 P transitions.…”

Forbidden Transitions in a Magneto-Optical Trap

“…Better control over laser parameters can provide amplitude data of quality high enough to be compared to theory, and to be of use, for example, in PNC experiments. We point out that other methods for measuring forbidden transition matrix elements, such as NWM [7] and polarization spectroscopy [22] have so far been implemented using pulsed lasers. The application of cw techniques demonstrated by us would make these methods more accurate and increase their resolution enabling them to account for atomic hyperfine structure.…”

Laser spectroscopy of the 5P3/2 → 6Pj (j = 1/2 and 3/2) electric dipole forbidden transitions in atomic rubidium

“…This is an electromagnetic excitation between one-electron states with the same value of the orbital angular momentum, and therefore is not allowed by the electric dipole selection rules. In that work the authors concluded that there was an unexpectedly large contribution of the magnetic dipole term to the transition [4]. This claim was later put to test in an experiment using cold atoms [5], and the conclusion was reached that there is no significant magnetic dipole contribution to this 5P → 8P non-dipole transition.…”

“…The first work studied the 5P → 8P transition in hot rubidium atoms induced by pulsed lasers [4]. This is an electromagnetic excitation between one-electron states with the same value of the orbital angular momentum, and therefore is not allowed by the electric dipole selection rules.…”