Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Phase Control In Atomic Coherence, Utsab Khadka Aug 2012

Phase Control In Atomic Coherence, Utsab Khadka

Graduate Theses and Dissertations

In this thesis, atomic coherence is used to enhance nonlinear optical processes in multi-level atoms. The multi-photon transitions are driven resonantly, and at the same time without absorptive losses, by using electromagnetically induced transparency (EIT), thereby allowing the study of χ(3) and χ(5) nonlinearities using weak driving fields. The coherently modified probe beam(s) and the atom-radiated signal fields arising from four- and six- wave- mixing (FWM and SWM) processes are measured in the spectral, temporal and spatial domains.

In a three-level ladder-type atomic system, multiple peaks having spectral asymmetries are observed in the EIT window as well as …


Investigation Of Negative Differential Resistance Phenomena In Quantum Well Heterostructures, Nazariy Andrushchak May 2012

Investigation Of Negative Differential Resistance Phenomena In Quantum Well Heterostructures, Nazariy Andrushchak

Graduate Theses and Dissertations

Increasing interest in entirely new possibilities for quantum mechanical description of carriers transport is becoming more evident with the developing advancements in epitaxial growth technique. Consequently, molecular beam epitaxy (MBE) technique is considered to be the most precise technique that allows the growth of ultra-thin layers of different compositions.

Those structures can be designed to investigate the wave-nature of carriers, which broadens the possibilities in device design and fabrication for a specific area. In this thesis the fundamental study of the real space charge transfer (RST) mechanism that took place in quantum well heterostructures and led to the negative differential …