Ultranarrow-bandwidth atomic filter with Raman light amplification.
A Raman-amplified atomic filter is demonstrated experimentally. With a coupling light detuned from the D2 line of 85Rb, a weak signal light can be amplified by a factor of 55, and the bandwidth of the filter's transmission spectrum is narrowed to approximately 60 MHz. Moreover, the transmission wavelength is adjustable by changing the coupling-light frequency. Compared with a conventional dispersive atomic filter, this Raman-amplified atomic filter could be more efficient to suppress background noise in free-space quantum-key distribution or a laser-communication system.
Shan
Xin
X
State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, China.
Sun
Xianping
X
Luo
Jun
J
Zhan
Mingsheng
M