A scheme for two-dimensional (2D) subwavelength atom localization is proposed, in which the atom is in a four-level tripod configuration and driven by two orthogonal standing-wave lasers. Because of the spatial dependence of atom–field interaction, the spontaneously emitted photon carries information about the position of the atom in standing-wave fields. We exploit this fact to 2D atom localization conditioned on the measurement of spontaneously emitted photon at a particular frequency, and obtain a high precision and resolution in the position probability distribution. Moreover, an improvement by a factor of 2 in the detecting probability of an atom can be achieved by initially preparing the atom in the coherent population trapping state. Qualitatively, the high- precision, high-resolution atom localization can be attributed to the quantum interference effect between competitive multiple spontaneous decay channels.
© 2011 Optical Society of America
Original Manuscript: August 26, 2010
Revised Manuscript: October 5, 2010
Manuscript Accepted: October 29, 2010
Published: December 6, 2010
Ren-Gang Wan, Jun Kou, Li Jiang, Yun Jiang, and Jin-Yue Gao, "Two-dimensional atom localization via controlled spontaneous emission from a driven tripod system," J. Opt. Soc. Am. B 28, 10-17 (2011)