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dc.contributor.advisorGülseren, Oğuz
dc.contributor.authorGündoğdu, Sinan
dc.date.accessioned2018-09-21T06:49:08Z
dc.date.available2018-09-21T06:49:08Z
dc.date.copyright2018-09
dc.date.issued2018-09
dc.date.submitted2018-09-20
dc.identifier.urihttp://hdl.handle.net/11693/47896
dc.descriptionCataloged from PDF version of article.en_US
dc.descriptionThesis (Ph.D.): Bilkent University, Department of Physics, İhsan Doğramacı Bilkent University, 2018.en_US
dc.descriptionIncludes bibliographical references (leaves 85-95).en_US
dc.description.abstractQuantum Cascade Lasers (QCLs) are coherent light sources that make use of intraband transitions of wavefunction engineered semiconductor quantum wells. They have been designed to emit light in a wide spectral range; from mid-wave infrared to terahertz. Long wave QCLs are a subject of interest for some applications such as remote detection of harmful chemicals. These applications demand higher optical powers at room temperature. In this thesis we demonstrate simulation, design, fabrication and characterization of long-wave QCLs that emit light around 9.2 m. To increase optical power and enhance thermal performance, we explore the optical and thermal properties of QCLs. Thermal characteristics of QCLs are analyzed by nite element methods. We developed a spectral technique that relies on analysis of Fabry-Perot modes to measure cavity temperatures experimentally. By combining the simulations and experimental results we scrutinized the thermal properties of QCLs, and estimated the active region thermal conductivity. To increase the optical power, we conducted optical calculations and investigated the sources of loss. As a result of a search for alternative electrical passivation materials, we fabricated HfO2 passivated lasers and demonstrated about to two-fold reduction in optical loss and increase in optical power.en_US
dc.description.statementofresponsibilityby Sinan Gündoğdu.en_US
dc.format.extentxiii, 108 leaves : charts (some color) ; 30 cm.en_US
dc.language.isoEnglishen_US
dc.rightsinfo:eu-repo/semantics/openAccessen_US
dc.subjectQuantum Cascade Lasersen_US
dc.subjectSemiconductor Lasersen_US
dc.titleOptical and thermal dynamics of long wave quantum cascade lasersen_US
dc.title.alternativeUzun dalgaboylu kuantum çağlayan lazerlerin optik ve ışıl dinamiklerien_US
dc.typeThesisen_US
dc.departmentDepartment of Physicsen_US
dc.publisherBilkent Universityen_US
dc.description.degreePh.D.en_US
dc.identifier.itemidB159022


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