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arXiv · 1405.7477

Velocity selective bi-polarization spectroscopy for laser cooling of metastable Krypton atoms

Y. B. Kale·V. B. Tiwari·S. Singh·S. R. Mishra·H. S. Rawat
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Abstract

We report a velocity selective bi-polarization spectroscopy (VS-BPS) technique to generate a background-free, dispersion-like reference signal which is tunable over a wide range of frequency. In this technique, a pair of linearly polarized weak probe beams passing through a gas cell of metastable Krypton (Kr*) atoms, overlaps with a pair of counter-propagating circularly polarized strong pump beams derived from an independently tunable control laser. The polarization spectroscopy signals from the two probe beams, after subtraction, result in VS-BPS signal. The spectral shifting in VS-BPS signal can be achieved by tuning the frequency of the control laser. The dependence of the amplitude and slope of the VS-BPS signal on the RF power used for excitation of Kr atoms in the gas cell and on the power of pump beams has been studied. The frequency stability of a diode laser locked with VS-BPS signal has been found to be better than the frequency stability of the laser locked with a saturated absorption spectroscopy (SAS) signal. The VS-BPS signal is finally used for stabilization and tuning of the cooling laser frequency for a magneto-optical trap (MOT) for Kr* atoms.

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Y. B. Kale, V. B. Tiwari, S. Singh, S. R. Mishra, H. S. Rawat. 2014-05-29. Velocity selective bi-polarization spectroscopy for laser cooling of metastable Krypton atoms. https://doi.org/10.1364/josab.31.002531

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