The Effect of the Hyperfine Structure of an Excited Level on the Shape of the Coherent Population Trapping Resonance und
- PDF / 654,882 Bytes
- 8 Pages / 612 x 792 pts (letter) Page_size
- 41 Downloads / 198 Views
MOLECULES, OPTICS
The Effect of the Hyperfine Structure of an Excited Level on the Shape of the Coherent Population Trapping Resonance under Ramsey Interrogation in an Optically Dense Medium G. V. Voloshina, K. A. Barantseva, E. N. Popova, and A. N. Litvinova,* a Peter
the Great St. Petersburg Polytechnic University, St. Petersburg, 195251 Russia *e-mail: [email protected]
Received December 10, 2018; revised December 10, 2018; accepted January 29, 2019
Abstract—The effect of the hyperfine structure of an excited level on the shape of the coherent population trapping (CPT) resonance under Ramsey interrogation is investigated in media with different optical thicknesses. The shape of the CPT resonance is constructed for optically thin and dense media, and the results are compared. The dependence of the light shift on the optical density of a medium is analyzed. The parameters of the field phases are determined for which the light shift remains constant under fluctuations of the optical thickness of the medium. DOI: 10.1134/S1063776119060086
A similar effect in cells with antirelaxation coating (without a buffer gas) was observed experimentally [13] and explained theoretically [14]. In [15], the authors studied the evolution of atomic coherence between Zeeman sublevels in a circular region between the pumping and reading laser beams in a gas cell with rubidium-87 vapor in the Hanle configuration. The analysis of the transmission coefficient of the probe beam showed the narrowing of the Hanle resonance. The above-listed works demonstrate that the use of the Ramsey interrogation scheme can give an additional possibility for narrowing the CPT resonance line. In the last 5–10 years, a sufficiently wide circle of specialists were engaged in the study of the application of pulsed pumping to narrow the CPT resonance line. In [16], the authors investigated multiband (the laser beam is split into several parallel narrow light beams) spectroscopy of alkali metal atoms without a buffer gas in the presence of a split light beam under CPT conditions. Obtaining a high-contrast signal of the CPT resonance with the use of the Ramsey interrogation scheme was considered in [17], and, in [18, 19], the authors carried out an experimental and theoretical study of the light shift under CPT conditions. The use of a periodic microwave modulation of current in vertical resonator lasers (vertical cavity surface emitting lasers, VCSEL) for the organization of the Ramsey scheme in atomic clocks based on the CPT effect was considered in [20]. Reduction of the light shift of the CPT resonance due to pulsed pumping was proposed in [21]. Investigation of the CPT resonance in the field of two linearly polarized waves with parallel polarization planes was carried out in [22] by Ramsey spec-
1. INTRODUCTION The use of nonlinear resonances in a two-frequency laser pumping scheme allows one to avoid the Doppler broadening and to significantly reduce the resonance linewidth. Coherent population trapping (CPT) resonances [1–4] have been widely us
Data Loading...
