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arXiv · 1610.03743

High Efficiency Raman Memory by Suppressing Radiation Trapping

S. E. Thomas·J. H. D. Munns·K. T. Kaczmarek·C. Qiu·B. Brecht·A. Feizpour·P. M. Ledingham·I. A. Walmsley·J. Nunn·D. J. Saunders
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Abstract

Raman interactions in alkali vapours are used in applications such as atomic clocks, optical signal processing, generation of squeezed light and Raman quantum memories for temporal multiplexing. To achieve a strong interaction the alkali ensemble needs both a large optical depth and a high level of spin-polarisation. We implement a technique known as quenching using a molecular buffer gas which allows near-perfect spin-polarisation of over $99.5\%$ in caesium vapour at high optical depths of up to $\sim 2 \times 10^5$; a factor of 4 higher than can be achieved without quenching. We use this system to explore efficient light storage with high gain in a GHz bandwidth Raman memory.

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S. E. Thomas, J. H. D. Munns, K. T. Kaczmarek, C. Qiu, B. Brecht, A. Feizpour, P. M. Ledingham, I. A. Walmsley, J. Nunn, D. J. Saunders. 2016-10-12. High Efficiency Raman Memory by Suppressing Radiation Trapping. https://doi.org/10.1088/1367-2630%2Faa7534

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