List of Division publications with links

2014-07-29 11:28 - Efficient optical pumping and high optical depth in a hollow-core photonic-crystal fiber for a broadband quantum memory

M. R. Sprague, D. G. England, A. Abdolvand, J. Nunn, X.-M. Jin, W. St. Kolthammer, M. Barbieri, B. Rigal, P. S. Michelberger, T. F. M. Champion, P. St. J. Russell and I. A. Walmsley, New Journal of Physics, Volume: 15, pp. 055013 (2013)

The generation of large multiphoton quantum states-for applications in computing, metrology and simulation-requires a network of high-efficiency quantum memories capable of storing broadband pulses. Integrating these memories into a fibre offers a number of advantages towards realizing this goal: strong light-matter coupling at low powers, simplified alignment and compatibility with existing photonic architectures. Here, we introduce a large-core kagome-structured hollow-core fibre as a suitable platform for an integrated fibre-based quantum memory with a warm atomic vapour. We demonstrate, for the first time, efficient optical pumping in such a system, where 90 ± 1% of atoms are prepared in the ground state. We measure high optical depths (3 × 104) and narrow homogeneous linewidths (6 ± 2 MHz) that do not exhibit significant transit-time broadening, showing that we can prepare a ?-level system in a pure state. Our results establish that kagome fibres are suitable for implementing a broadband, room-temperature quantum memory, as well as a range of nonlinear optical effects.