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dc.contributor.authorTiaz, Gul-
dc.description.abstractMultiple Colors Electromagnetically Induced Switching and Spectral Holes Burning in the Transmission of a Probe Light Through Atomic Media Preservation of coherence effect in a medium by coupling fields could be interesting for controlled multiple color Electromagnetically Induced Switching (EIS) and multiple color Spontaneous Scattering Light (SSL) due to their numerous useful applications. A four-level atomic medium cyclically driven by two optical and one microwave field produces double resonance for a weak probe field absorption and SSL. The double resonance produced in the spectrum switches into a typical asymmetric Fano-like resonance with and without the influences from the wave-vector mismatch (WVM) and Doppler effect, using relative phase of collinear driving fields and vice versa. In case of EIT, a non-linear input-out theory in presence of atomic dephasing reservoir is further developed to quantitatively measure EIS of the time delay into the time advancement of a probe Gaussian light pulse. The EIS of a weak probe field through and SSL from a five-level atomic medium, driven cyclically by two optical and two microwave fields, are next investigated. Caused by the resonant (off resonant) atom-field interaction, in each case of the spectrum, a triple symmetric (asymmetric) resonance exhibits in the spectrum. Using the relative phase of the coupling fields, the triple resonance switches into double and single resonance and vice versa. In the case of the probe absorption, the triple EIS becomes free of the WVM and Doppler effect due to the co-linear coupling of the fields. The atomic dephasing rates in the medium also tune the EIT and SSL from the triple through the single EIT into a Lorentzian line. Furthermore, in presence of the atom dephasing reservoir interplay between the coherence controlled multiple EIT and Autler-Townes effect (ATE) in the spectrum is investigated using dressed states analysis. We show that the competition between the EIT and ATE can be controlled by tuning threshold dephasing rates and threshold coupling strengths. Independent of the WVM and Doppler effect, a warm temperature medium of five atomic system is next considered to measure the atomic position in three dimensions in an optical cavity using orthogonal standing and traveling wave fields. The precision of atomic position xi in the cavity could be controlled by adjusting the intensities, relative phase and relative direction of propagation of the driving fields with respect to the atomic velocity in the cavity. Finally, we study a tripod type four-level atomic system for burning multiple spectral holes in the inhomogeneous absorption spectrum of a weak probe field through the medium. We find that the Spectral Hole Burning (SHB) necessarily requires Doppler broadened medium where propagation of either one or both of the coupling fields are considered to be counter co-linear to the probe field in a vapor cell. Various classes of varying average atomic velocity are considered in the medium when a suitable lighter buffer gas is introduced into the vapor cell. Based on the classes of high average atomic velocity, the number of SHBs associated with different parts of the absorption spectrum increases. The position, width, depths and numbers of the multiple SHBs are analyzed using suitable parameters of the atomic system.en_US
dc.description.sponsorshipHigher Education Commission Pakistanen_US
dc.publisherCOMSATS University, Islamabad.en_US
dc.subjectPhysical Sciencesen_US
dc.titleMultiple Colors Electromagnetically Induced Switching and Spectral Holes Burning in the Transmission of a Probe Light Through Atomic Mediaen_US
Appears in Collections:PhD Thesis of All Public / Private Sector Universities / DAIs.

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