Optical pumping and coherence effects in fluorescence from a four level system

Narayanan, Andal

Please use this identifier to cite or link to this item: http://hdl.handle.net/2289/2308

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DC Field	Value	Language
dc.contributor.author	Narayanan, Andal	-
dc.date.accessioned	2007-05-14T09:59:10Z	-
dc.date.available	2007-05-14T09:59:10Z	-
dc.date.issued	2006-07	-
dc.identifier.citation	European Physical Journal D, 2006, Vol.39, p13-22	en
dc.identifier.issn	1434-6060	-
dc.identifier.issn	1434-6079 (Online)	-
dc.identifier.uri	http://hdl.handle.net/2289/2308	-
dc.description	Restricted Access.	en
dc.description.abstract	An effective four-level system around the D2 line of 85Rb at room temperature, is experimentally investigated by fluorescent studies under the action of two driving fields L1 and L2. This system exhibits unique features in fluorescence as a function of frequency separation between L1 and L2. In particular, at two-photon resonance, when the Rabi frequency of L1 exceeds that of L2, signatures of Electromagnetically Induced Transperancy effect (EIT) arising from the three-level $\Lambda$ sub-system is present as a sub-natural dip in fluorescence from the fourth level. At comparable strengths of L1 and L2 the fluorescence features indicate a regime, where the effects arising from optical pumping and EIT effect due to ground hyperfine level coherence coexist. We see in the coexistence regime, saturation effects arising from difference frequency crossing (DFC) resonances and optical pumping around the EIT window. At low strengths of L1, all signs of coherence vanishes from the system and the fluorescent features result from incoherent optical pumping through the Autler-Townes split states of the excited state hyperfine levels, which are split due to the stronger L2 laser. The dominant role of the L1 laser in creating a robust transparency signal even in the presence of an off-resonant excitation is brought out. The results are supported by density matrix calculations.	en
dc.format.extent	317661 bytes	-
dc.format.mimetype	application/pdf	-
dc.language.iso	en	en
dc.publisher	Springer Verlag	en
dc.relation.uri	http://dx.doi.org/10.1140/epjd/e2006-00108-1	en
dc.rights	2006 Springer-Verlag	en
dc.title	Optical pumping and coherence effects in fluorescence from a four level system	en
dc.type	Article	en
Appears in Collections:	Research Papers (LAMP)

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