We investigate the sensitivity limit of absorption spectroscopy. An experiment is described in which the decrease in transmitted light intensity that is due to absorption by a single, electromagnetically confined atomic ion is observed.
© 1987 Optical Society of America
D. J. Wineland, Wayne M. Itano, and J. C. Bergquist, "Absorption spectroscopy at the limit: detection of a single atom," Opt. Lett. 12, 389-391 (1987)