Dual Channel Light Storage Based On Electromagnetically Induced Transparency In Hot Rb Vapor

As a kind of information carrier, light with a fastest propagating speed innature, has itself advantages on transmitting and inducing signals that other mattersare lacking. With the development of modern optics technology, researches ondiverse patterns of light is getting much more. Among them, efficiently storing andretrieving optical information is still a difficulty and hot-spot. But the application ofelectromagnetically induced transparency technique has been providing a powerfultool to practically manipulate light pattern. While completing and developing thetechnique, people also make great efforts to reforming it. This paper experimentallyresearches the dual channel light storage process based on electromagneticallyinduced transparency technique in hot Rb vapor.1. Research on electromagnetically induced transparency effects in dualchannel light storage. We relatively introduce the principle, application anddevelopment of electromagnetically induced transparency effect, and discuss themerits and defects of hot Rb vapor as medium. Detailedly illuminate respectiveelectromagnetically induced transparency phenomena of two Rb isotopes(85Rband87Rb) in dual optic channels with independent detunings and draw a conclusionthat in the same hot Rb vapor medium the phenomenon of85Rbatoms is muchworse than that of87Rbatoms. The reason about the result is that control field in85Rbatoms has interacted with other unexpected atomic transition levels.Meanwhile, it is also at resonance with the “shift” levels generated by Dopplereffect. After the contrast and analysis we can as well acquire that in Rb atomicvapor the less the detuning is, the better the effects of electromagnetically inducedtransparency in probe field are. This is result in the strong Doppler broadeningeffect on atomic levels. However, the adjustment and displacement of EIT dipexactly depends on such inhomogeneous broadening effects due to dramaticallyatomic thermal motion. 2. Experimental analysis on dual channel light storage based on EIT in hot Rbvapor. We mainly introduce the experiment process of dual channel optical memoryin the case of existing relative large detunings. By the means of atomic levelshifting, we choose the equal frequencies in mutual probe field signals to realizeelectromagnetically induced transparency and light storage. Then we conclude thatthe energy of probe signal pulse has been partially transferred to generateFour-wave mixing signals in Rb atom, and such transfer badly influences the finaleffect of dual channel light storage. Although heating the sample can obtain betteroptical depth of Rb vapor, Four-wave mixing effect also becomes more significant.Especially in85Rbatoms, the structure of its atomic levels facilitates generatingFour-wave mixing signal. This result is consistent with that of previous researches.We illustrate that it is practicable to conduct dual channel light storage in hot Rbvapor based on electromagnetically induced transparency technique, and moreoverpropose a reforming experimental scheme about light storage to support the furtherrelevant researches.