Change in the absorption spectrum of sodium vapors in a magnetic field

R. Holzner, B. Röhricht, Patrik Eschle +3 more

Friedrich Blaha

Alexei G. Leonov, A. A. Panteleev, А. Н. Старостин +1 more

Hyun Joon Lee, Han Seb Moon

We investigated the switching between the transmittance and absorption of the 5S1/2(F=2)→5P1/2(F′=1) transition of Rb87 in a paraffin-coated Rb vapor cell in the Hanle configuration. When the laser polarization was changed from linear to circular, the coherent population trapping (CPT) spectrum, with a spectral width of 0.12 mG due to the Ramsey effect, transformed into a narrow absorption spectrum with a sub-milligauss spectral width of 0.2 mG. The CPT and narrow absorption spectra were numerically calculated for both polarizations by considering the degenerate magnetic sublevels of the 5S1/2–5P1/2 transition in the antirelaxation-coated atomic vapor cell. This narrow absorption spectrum was revealed to be magnetic-field-induced absorption due to the residual transverse magnetic field and preservation time of the ground-state coherent spin states.

Robert John Strutt

Ho-Jung Kim, Han Seb Moon

We report on electromagnetically induced absorption (EIA) with sub-kHz spectral width in a paraffin-coated Rb vapor cell in the Hanle configuration of the 5S(1/2)(F=2)-5P(3/2)(F'=3) transition of 87Rb atoms. Using a linearly polarized laser, the spectral width of the Hanle EIA spectrum was measured to be 0.55 mG (390 Hz). The narrow spectral width was due to the maintaining of atomic coherence between ground states while atoms collided with the anti-relaxation coated wall of the Rb vapor cell. Under a weak transverse residual magnetic field, the angle between the transverse residual magnetic field and the direction of linear polarization affected the magnitude of the narrow Hanle EIA spectrum. This is because of the change of atomic magnetic momentum due to the weak transverse residual magnetic field around the zero value of the longitudinal magnetic field.