16p-D-6 Coherent effects of Optically oriented atomos on pumping light beams

幹雄 山下, 努 藪崎, 徹 小川

Rongtong Zhu, Jianli Li, Shuo Sun +4 more

Single-beam optically pumped atomic magnetometers (OPAMs) represent promising candidates for applications in geomagnetic field monitoring, biomedicine, and various other precision sensing domains owing to their exceptional sensitivity, high measurement accuracy, and cost-effectiveness. However, in orientation-based OPAMs utilizing circularly polarized light (CPL) pumping, the off-resonant light introduces light shift. The light shift acts as an additional magnetic field, reducing the measurement accuracy of OPAMs. Moreover, the dependence of the light shift on light intensity and frequency facilitates the conversion of light noise into magnetic noise, thereby degrading the sensitivity of OPAMs. In this study, we propose an optical pumping scheme based on space division multiplexing light (SDML) to suppress the light shift in OPAM. The approach employs two orthogonally polarized linearly polarized beams with a controlled phase difference to generate a spatially periodic distribution of left- and right-handed CPL. Optical pumping with the SDML induces oppositely directed light shifts in distinct spatial regions that effectively cancel each other. Finally, it is verified by experiments that the light shift is greatly suppressed based on SDML. Under detuned SDML pumping, both the light shift and light intensity noise are suppressed by over 50%, while maintaining a sensitivity comparable to that achieved with conventional CPL pumping. The proposed method demonstrates significant potential for magnetometers in light-noise-prone environments, and it can be generalized to other orientation-based magnetometers that rely on CPL pumping.

A. Besedina, Gennadij I. Khvostenko, М. П. Чайка

C.G. Aminoff, M. Pinard

We consider optical pumping with a quasi monochromatic tunable light beam, in the low intensity limit where a rate equation regime is obtained The velocity selective optical pumping (V.S.O.P.) introduces a correlation between atomic velocity and internal variables in the ground (or metastable) state. The aim of this article is to evaluate these atomic observables (orientation, alignment, population) as a function of velocity, using a phenomenological description of the relaxation effect of collisions. The V.S.O.P. line shapes, obtained by scanning the pumping beam frequency and using a counterpropagating detection beam with the same frequency, are given in various circumstances. The combination of V.S.O.P. with modulated pumping, magnetic resonance, and level crossing methods is considered; the corresponding line shapes can provide useful information on the relaxation characteristics, such as collision rates and kernels.

Evgenii B. Aleksandrov, N. N. Yakobson

Evgenii B. Aleksandrov, N. N. Yakobson