Consequences of induced transparency in a double-Λ scheme: Destructive interference in four-wave mixing
Document Type
Article
Publication Date
6-3-2002
Publication Title
Physical Review A
DOI
10.1103/PhysRevA.65.063806
ISSN
2469-9934
Abstract
We investigate a four-state system interacting with long and short laser pulses in a weak probe beam approximation. We show that when all lasers are tuned to the exact unperturbed resonances, part of the four-wave mixing (FWM) field is strongly absorbed. The part that is not absorbed has the exact intensity required to destructively interfere with the excitation pathway involved in producing the FWM state. We show that with this three-photon destructive interference, the conversion efficiency can still be as high as 25%. Contrary to common belief, our calculation shows that this process, where an ideal one-photon electromagnetically induced transparency is established, is not most suitable for high-efficiency conversion. With appropriate phase matching and propagation distance, and when the three-photon destructive interference does not occur, we show that the photon flux conversion efficiency is independent of probe intensity and can be close to 100%. In addition, we show clearly that the conversion efficiency is not determined by the maximum atomic coherence between two lower excited states, as commonly believed. It is the combination of phase matching and constructive interference involving the two terms arising in producing the mixing wave that is the key element for the optimized FWM generation. Indeed, in this scheme no appreciable excited state is produced, so that the atomic coherence between states |0〉 and |2〉 is always very small.
Recommended Citation
Payne, Marvin G., Lu Deng.
2002.
"Consequences of induced transparency in a double-Λ scheme: Destructive interference in four-wave mixing."
Physical Review A, 65 (6): American Physical Society.
doi: 10.1103/PhysRevA.65.063806 source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.65.063806
https://digitalcommons.georgiasouthern.edu/physics-facpubs/183
Comments
Authors have the right to use all or part of the Article, including the APS-prepared version without revision or modification, on the author(s)’ web home page or employer’s website. (source: http://journals.aps.org/authors/transfer-of-copyright-agreement) Article obtained from Physical Review A.