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arXiv · 1510.04625

A Cavity-Enhanced Room-Temperature Broadband Raman Memory

D. J. Saunders·J. H. D. Munns·T. F. M. Champion·C. Qiu·K. T. Kaczmarek·E. Poem·P. M. Ledingham·I. A. Walmsley·J. Nunn
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Abstract

Broadband quantum memories hold great promise as multiplexing elements in future photonic quantum information protocols. Alkali vapour Raman memories combine high-bandwidth storage, on-demand read-out, and operation at room temperature without collisional fluorescence noise. However, previous implementations have required large control pulse energies and suffered from four-wave mixing noise. Here we present a Raman memory where the storage interaction is enhanced by a low-finesse birefringent cavity tuned into simultaneous resonance with the signal and control fields, dramatically reducing the energy required to drive the memory. By engineering anti-resonance for the anti-Stokes field, we also suppress the four-wave mixing noise and report the lowest unconditional noise floor yet achieved in a Raman-type warm vapour memory, $(15\pm2)\times10^{-3}$ photons per pulse, with a total efficiency of $(9.5\pm0.5)$%.

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D. J. Saunders, J. H. D. Munns, T. F. M. Champion, C. Qiu, K. T. Kaczmarek, E. Poem, P. M. Ledingham, I. A. Walmsley, J. Nunn. 2015-10-15. A Cavity-Enhanced Room-Temperature Broadband Raman Memory. https://doi.org/10.1103/physrevlett.116.090501

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