title: Stationary light pulses in cold atomic media and without Bragg gratings.
abstract: We study the creation of stationary light pulses (SLPs), i.e., light pulses without motion, based on the effect of electromagnetically induced transparency with two counterpropagating coupling fields in cold atoms. We show that the Raman excitations created by counterpropagating probe and coupling fields prohibit the formation of SLPs in media of cold and stationary atoms such as laser-cooled atom clouds, Bose condensates or color-center crystals. A method is experimentally demonstrated to suppress these Raman excitations and SLPs are realized in laser-cooled atoms. Furthermore, we report the first experimental observation of a bichromatic SLP at wavelengths for which no Bragg grating can be established. Our work advances the understanding of SLPs and opens a new avenue to SLP studies for few-photon nonlinear interactions.
authors.affiliation: Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan, Republic of China.
authors.forename: Yen-Wei
authors.initials: YW
authors.lastname: Lin
authors.forename: Wen-Te
authors.initials: WT
authors.lastname: Liao
authors.forename: Thorsten
authors.initials: T
authors.lastname: Peters
authors.forename: Hung-Chih
authors.initials: HC
authors.lastname: Chou
authors.forename: Jian-Siung
authors.initials: JS
authors.lastname: Wang
authors.forename: Hung-Wen
authors.initials: HW
authors.lastname: Cho
authors.forename: Pei-Chen
authors.initials: PC
authors.lastname: Kuan
authors.forename: Ite A
authors.initials: IA
authors.lastname: Yu