alexa Control Of Coherence In A Ξ System And Its Utility In Optical Switching | 20693
ISSN: 2161-0398

Journal of Physical Chemistry & Biophysics
Open Access

Like us on:
OMICS International organises 3000+ Global Conferenceseries Events every year across USA, Europe & Asia with support from 1000 more scientific Societies and Publishes 700+ Open Access Journals which contains over 50000 eminent personalities, reputed scientists as editorial board members.

Open Access Journals gaining more Readers and Citations

700 Journals and 15,000,000 Readers Each Journal is getting 25,000+ Readers

This Readership is 10 times more when compared to other Subscription Journals (Source: Google Analytics)

2nd International Conference and Exhibition on Lasers, Optics & Photonics
September 08-10, 2014 Hilton Philadelphia Airport, USA

Ayan Ray, Md Sabir Ali and Alok Chakrabarti
ScientificTracks Abstracts: J Phys Chem Biophys
DOI: 10.4172/2161-0398.S1.006
Abstract
Implementation of the idea of coherence control in a multilevel atom-photon interaction has remained as a key topic of research and proves to be helpful in many frontline applications including optical switching. The possible methods of control of coherence may include selective transfer of population, interaction of multiple dark states etc. We demonstrated such kind of control in case of a Ξ system comprising of 5S 1/2 (F)→5P 3/2 (F/)→5D 5/2 (F//) levels of 87 Rb atom. This particular level scheme is important in view of its wide application in metrology, frequency conversion, atomic line filter (5D 3/2 in this case) etc. However with recent progress in research, it has been found that Electromagnetically Induced Transparency (EIT) in a Ξ system is associated with background of double resonance optical pumping (DROP) for cyclic probe transition (e.g. F=2→F/=3 ). As strong EIT condition requires population confinement within the concerned Ξ level coupling, the DROP itself originates from loss of population to F=1 state. This counter-intuitive requirement sets the backdrop of our present work. We introduced a third laser (named Repump after convention used in Laser Cooling experiment) connecting F=1→F/ =2 for controlling the coherence in the medium. Depending on the direction of propagation of Repump (counter or co) w.r.t probe laser, the existing Λ (probe-repump) system either exhibits (i) velocity selective Raman type population transfer or (ii) a narrow (subnatural) EIT. For the first case we have shown that the repumping process may be made more selective if it is taken to degenerate zeeman sub-level basis (σ+ polarized) compared to hyperfine level repumping (linearly polarized). This study is further supported by monitoring of blue fluorescence (~420 nm) in the {5S 1/2 (F)→6P 3/2 (F /// )} →5D 5/2 (F // ) decay channel. It shows the relative population history at 5D5/2(F//) under various conditions; which directly shows enhancement of two photon interaction under re-pump process. However the figure of merit for coherence control is measured via. Line width of EIT (ΓEIT) and relative line strength vs. re-pump intensity. It shows that the σ+ Repump is most efficient in strengthening EIT with a vis. a vis. preservation of the sub-natural character of ΓEIT. This setup is implemented in case of a slow-fast dual mode optically switchable DROP-EIT rich medium and it is found that indeed the repump process helps in attaining better modulation depth by efficiently retrieving the ?Radiation Trapped? atoms from F=1 state. As a matter of fact we had also shown the beneficial aspect of repumping process in case of an ALF. Considering the second (ii) kind of coherence control method, which involves interaction of nearly degenerate Dark states, is an ongoing study and we are yet to arrive at a definite conclusion over its prospective beneficial role.
Biography
Ayan Ray has completed his PhD at the age of 30 years (2005) from University of Calcutta. He spent a brief stay at Optics Group, University of Melbourne and Laser Physics Application Spection, Raja Ramanna Centre for Advanced Technology (RRCAT) to pursue Postdoctoral studies (2005-06). Later on he moved to Atomic Physics and Quantum Optics Section, Bhabha Atomic Research Centre (2006-10). Currently he is working in Radioactive Ion Beam Facility Group, Variable Energy Cyclotron Centre (2010 onwards).
image PDF   |   image HTML
 
Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2018-19
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

Agri & Aquaculture Journals

Dr. Krish

[email protected]

1-702-714-7001Extn: 9040

Biochemistry Journals

Datta A

[email protected]

1-702-714-7001Extn: 9037

Business & Management Journals

Ronald

[email protected]

1-702-714-7001Extn: 9042

Chemistry Journals

Gabriel Shaw

[email protected]

1-702-714-7001Extn: 9040

Clinical Journals

Datta A

[email protected]

1-702-714-7001Extn: 9037

Engineering Journals

James Franklin

[email protected]

1-702-714-7001Extn: 9042

Food & Nutrition Journals

Katie Wilson

[email protected]

1-702-714-7001Extn: 9042

General Science

Andrea Jason

[email protected]

1-702-714-7001Extn: 9043

Genetics & Molecular Biology Journals

Anna Melissa

[email protected]

1-702-714-7001Extn: 9006

Immunology & Microbiology Journals

David Gorantl

[email protected]

1-702-714-7001Extn: 9014

Materials Science Journals

Rachle Green

[email protected]

1-702-714-7001Extn: 9039

Nursing & Health Care Journals

Stephanie Skinner

[email protected]

1-702-714-7001Extn: 9039

Medical Journals

Nimmi Anna

[email protected]

1-702-714-7001Extn: 9038

Neuroscience & Psychology Journals

Nathan T

[email protected]

1-702-714-7001Extn: 9041

Pharmaceutical Sciences Journals

Ann Jose

[email protected]

1-702-714-7001Extn: 9007

Social & Political Science Journals

Steve Harry

[email protected]

1-702-714-7001Extn: 9042

 
© 2008- 2018 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version