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arXiv · 1612.04583

Sub-Doppler laser cooling of 40K with Raman gray molasses on the D2 line

G. D. Bruce·E. Haller·B. Peaudecerf·D. A. Cotta·M. Andia·S. Wu·M. Y. H. Johnson·B. W. Lovett·S. Kuhr
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Abstract

Gray molasses is a powerful tool for sub-Doppler laser cooling of atoms to low temperatures. For alkaline atoms, this technique is commonly implemented with cooling lasers which are blue-detuned from either the D1 or D2 line. Here we show that efficient gray molasses can be implemented on the D2 line of 40K with red-detuned lasers. We obtained temperatures of 48(2) microKelvin, which enables direct loading of 9.2(3)*10^6 atoms from a magneto-optical trap into an optical dipole trap. We support our findings by a one-dimensional model and three-dimensional numerical simulations of the optical Bloch equations which qualitatively reproduce the experimentally observed cooling effects.

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G. D. Bruce, E. Haller, B. Peaudecerf, D. A. Cotta, M. Andia, S. Wu, M. Y. H. Johnson, B. W. Lovett, S. Kuhr. 2016-12-14. Sub-Doppler laser cooling of 40K with Raman gray molasses on the D2 line. https://doi.org/10.1088/1361-6455%2Faa65ea

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