@article {2243,
	title = {Low-light-level four-wave mixing by quantum interference},
	journal = {Phys. Rev. A},
	volume = {89},
	year = {2014},
	pages = {5},
	abstract = {<p>We observed electromagnetically induced transparency-based four-wave mixing (FWM) in the pulsed regime at low light levels. The FWM conversion efficiency of 3.8(9)\% was observed in a four-level system of cold 87Rb atoms using a driving laser pulse with a peak intensity of ≈80 μW/cm2, corresponding to an energy of ≈60 photons per atomic cross section. Comparison between the experimental data and the theoretical predictions proposed by Harris and Hau [Phys. Rev. Lett. 82, 4611 (1999)] showed good agreement. Additionally, a high conversion efficiency of 46(2)\% was demonstrated when applying this scheme using a driving laser intensity of ≈1.8 mW/cm2. According to our theoretical predictions, this FWM scheme can achieve a conversion efficiency of nearly 100\% when using a dense medium with an optical depth of 500.</p>
},
	author = {Chang-Kai Chiu and Yi-Hsin Chen and Chen, Yen-Chun and Ite A. Yu and Ying-Cheng Chen and Yong-Fan Chen}
}
