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dc.contributor.advisorCohen, Adam Ezra
dc.contributor.authorTang, Yiqiao
dc.date.accessioned2013-03-18T18:30:19Z
dc.date.issued2013-03-18
dc.date.submitted2012
dc.identifier.citationTang, Yiqiao. 2012. Chirality of Light and Its Interaction with Chiral Matter. Doctoral dissertation, Harvard University.en_US
dc.identifier.otherhttp://dissertations.umi.com/gsas.harvard:10672en
dc.identifier.urihttp://nrs.harvard.edu/urn-3:HUL.InstRepos:10436269
dc.description.abstractThis thesis conducts a systematic study on the chirality of light and its interaction with chiral matter. In the theory section, we introduce a measure of local density of chirality, applying to arbitrary electromagnetic fields. This optical chirality suggests the existence of superchiral modes, which are more selective than circularly polarized light (CPL) in preferentially exciting single enantiomers in certain regions of space. Experimentally, we demonstrate an 11-fold enhancement over CPL in discriminating chiral fluorophores of single handedness in a precisely sculpted superchiral field. This result agrees to within 15% with theoretical predictions. Any chiral configuration of point charges is beyond the scope of our theory on optical chirality. To address chiroptical excitations at nanoscale, we develop a model of twisted dipolar oscillators. We design a simple tunable chiral nanostructure and observe localized chiroptical “hot spots” with dramatically enhanced circular differential scattering. Our work on superchiral light and 3D chiral metamaterials establishes optical chirality as a fundamental and tunable property of light, with implications ranging from plasmonic sensors, absolute asymmetric synthesis to new strategies for fabricating three-dimensional chiral metamaterials. This thesis is organized as such: Chapter 1 provides a background on previous studies of chiroptical phenomena, and recent efforts in preparing chiral metamaterials. Chapter 2 derives theory on optical chirality, superchiral modes and coupled-dipolar oscillators at nanoscale. Chapter 3 introduces material, apparatus, and pitfalls in chiroptical experiments. Chapter 4 is an overview of the experimental procedure and results on generating and observing superchiral enhancement. Chapter 5 describes the experiments on using spectroscopic polarization microscopy to study chiral 3D chiral metamaterials. Finally in Chapter 6, I discuss quantization of optical chirality and perspectives on future directions.en_US
dc.description.sponsorshipPhysicsen_US
dc.language.isoen_USen_US
dash.licenseLAA
dc.subjectPhysicsen_US
dc.subjectPhysical chemistryen_US
dc.subjectOpticsen_US
dc.subjectchiral metamaterialen_US
dc.subjectcircular dichroismen_US
dc.subjectoptical chiralityen_US
dc.subjectsuperchiralityen_US
dc.titleChirality of Light and Its Interaction with Chiral Matteren_US
dc.typeThesis or Dissertationen_US
dc.date.available2013-03-18T18:30:19Z
thesis.degree.date2012en_US
thesis.degree.disciplinePhysicsen_US
thesis.degree.grantorHarvard Universityen_US
thesis.degree.leveldoctoralen_US
thesis.degree.namePh.D.en_US
dc.contributor.committeeMemberWalsworth, Ronalden_US
dc.contributor.committeeMemberNelson, Daviden_US
dash.contributor.affiliatedTang, Yiqiao


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