Eur. Phys. J. D (2016) 70: 262
https://doi.org/10.1140/epjd/e2016-70428-6

Regular Article

Contrast enhancement via shaped Raman pulses for thermal cold atom cloud interferometry

¹ Department of Instrument Science and Technology, College of Mechatronic Engineering and Automation, National University of Defense Technology, Changsha, Hunan 410073, P.R. China
² Interdisciplinary Center for Quantum Information, National University of Defense Technology, Changsha, Hunan 410073, P.R. China

^a e-mail: yk.luo@nudt.edu.cn

Received: 5 July 2016
Received in final form: 20 September 2016
Published online: 15 December 2016

Abstract

Interferometry with thermal cold atom clouds provides high particle flux and low quantum projection noise but is limited by the rapid reduction of fringe contrast. We propose an improved method based on temporally shaped pulses to address the issue of the off-resonance dispersion and enhance the contrast. Theoretical analysis and construction principle for shaped pulses are demonstrated. The fidelity of single π and π/2 pulses as well as a complete interferometer sequence are investigated. Comparisons are ade between the traditional pulse and several alternative shaped pulses to verify the feasibility and find an efficient choice among them. Practical implementation scheme and possible error sources are also discussed. The results show a great improvement in contrast and robust phase response for high atomic temperature up to several tens of μK.