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Four wave mixing with self-phase matching due to collective atomic recoil

G. R. M. Robb·B. W. J. McNeil
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Abstract

We describe a method for non-degenerate four-wave mixing in a cold sample of 4-level atoms. An integral part of the four-wave mixing process is a collective instability which spontaneously generates a periodic density modulation in the cold atomic sample with a period equal to half of the wavelength of the generated high-frequency optical field. Due to the generation of this density modulation, phase-matching between the pump and scattered fields is not a necessary initial condition for this wave-mixing process to occur, rather the density modulation acts to "self phase-match" the fields during the course of the wave-mixing process. We describe a one-dimensional model of this process, and suggest a proof-of-principle experiment which would involve pumping a sample of cold Cs atoms with three infra-red pump fields to produce blue light.

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G. R. M. Robb, B. W. J. McNeil. 2004-12-23. Four wave mixing with self-phase matching due to collective atomic recoil. https://doi.org/10.1103/physrevlett.94.023901

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