S. Bennetts

Publications (3)3.59 Total impact

• Article: Optically guided linear Mach Zehnder atom interferometer

  G. D. McDonald, H. Keal, P. A. Altin, J. E. Debs, S. Bennetts, C. C. N. Kuhn, K. S. Hardman, M. T. Johnsson, J. D. Close, N. P. Robins
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  ABSTRACT: We demonstrate a horizontal, linearly guided Mach Zehnder atom interferometer in an optical waveguide. Intended as a proof-of-principle experiment, the interferometer utilises a Bose-Einstein condensate in the magnetically insensitive |F=1,mF=0> state of Rubidium-87 as an acceleration sensitive test mass. We achieve a modest sensitivity to acceleration of da = 7x10^-4 m/s^2. Our fringe visibility is as high as 38% in this optically guided atom interferometer. We observe a time-of-flight in the waveguide of over half a second, demonstrating the utility of our optical guide for future sensors.
  12/2012;
• Article: Precision atomic gravimeter based on Bragg diffraction

  P. A. Altin, M. T. Johnsson, V. Negnevitsky, G. R. Dennis, R. P. Anderson, J. E. Debs, S. S. Szigeti, K. S. Hardman, S. Bennetts, G. D. McDonald, L. D. Turner, J. D. Close, N. P. Robins
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  ABSTRACT: We present a precision gravimeter based on coherent Bragg diffraction of freely falling cold atoms. Traditionally, atomic gravimeters have used stimulated Raman transitions to separate clouds in momentum space by driving transitions between two internal atomic states. Bragg interferometers utilize only a single internal state, and can therefore be less susceptible to environmental perturbations. Here we show that atoms extracted from a magneto-optical trap using an accelerating optical lattice are a suitable source for a Bragg atom interferometer, allowing efficient beamsplitting and subsequent separation of momentum states for detection. Despite the inherently multi-state nature of atom diffraction, we are able to build a Mach-Zehnder interferometer using Bragg scattering which achieves a sensitivity to the gravitational acceleration of $\Delta g/g = 2.7\times10^{-9}$ with an integration time of 1000s. The device can also be converted to a gravity gradiometer by a simple modification of the light pulse sequence.
  07/2012;
• Source

  Available from: ArXiv

  Article: 11 W narrow linewidth laser source at 780 nm for laser cooling and manipulation of Rubidium.

  S S Sané, S Bennetts, J E Debs, C C N Kuhn, G D McDonald, P A Altin, J D Close, N P Robins
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  ABSTRACT: We present a narrow linewidth continuous laser source with over 11 W output power at 780 nm, based on single-pass frequency doubling of an amplified 1560 nm fibre laser with 36% efficiency. This source offers a combination of high power, simplicity, mode quality and stability. Without any active stabilization, the linewidth is measured to be below 10 kHz. The fibre seed is tunable over 60 GHz, which allows access to the D₂ transitions in ⁸⁷Rb and ⁸⁵Rb, providing a viable high-power source for laser cooling as well as for large-momentum-transfer beamsplitters in atom interferometry. Sources of this type will pave the way for a new generation of high flux, high duty-cycle degenerate quantum gas experiments.
  Optics Express 04/2012; 20(8):8915-9. · 3.59 Impact Factor