Two-photon free-induction decay with electromagnetically induced transparency.
We report the observation of coherent two-photon free-induction decay (FID) in a three-level Lambda system excited by a low-intensity square-modulated laser pulse. Using electromagnetically induced transparency in an Rb85 cold atomic cloud, for what we believe to be the first time, we observe FID signals with coherence time exceeding the relevant atomic excited-state natural lifetime. Because of the on-resonance enhancement, the two-photon FID signal can be observed at the falling edge without using heterodyne means.
Department of Physics, The Hong Kong University of Science and Technology,Clear Water Bay, Kowloon, Hong Kong, China.
J F
JF
Chen
Weixin
W
Lu
Shuyuan
S
Wang
M M T
MM
Loy
G K L
GK
Wong
Shengwang
S
Du