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dc.contributor.advisorDholakia, Kishan
dc.contributor.advisorKrauss, Thomas F.
dc.contributor.authorDienerowitz, Maria
dc.description.abstractOptical trapping of metal nanoparticles investigates phenomena at the interface of plasmonics and optical micromanipulation. This thesis combines ideas of optical properties of metals originating from solid state physics with force mechanism resulting from optical trapping. We explore the influence of the particle plasmon resonance of gold and silver nanospheres on their trapping properties. We aspire to predict the force mechanisms of resonant metal particles with sizes in the Mie regime, beyond the Rayleigh limit. Optical trapping of metal nanoparticles is still considered difficult, yet it provides an excellent tool to investigate their plasmonic properties away from any interface and offers opportunities to investigate interaction processes between light and nanoparticles. Due to their intrinsic plasmon resonance, metal nanoparticles show intriguing optical responses upon interaction with laser light. These differ greatly from the well-known bulk properties of the same material. A given metal nanoparticle may either be attracted or repelled by laser light, only depending on the wavelength of the latter. The optical forces acting on the particle depend directly on its polarisability and scattering cross section. These parameters vary drastically around the plasmon resonance and thus not only change the magnitude but also the direction and entire nature of the acting forces. We distinguish between red-detuned and blue-detuned trapping, that is using a trapping wavelength shorter or longer than the plasmon resonance of the particle. So far optical trapping of metal nanoparticles has focussed on a wavelength regime far from the particle’s resonance in the infrared. We experiment with laser wavelengths close to the plasmon resonance and expand the knowledge of metal nanoparticle trapping available to date. Existing theoretical models are put to the test when we compare these with our real experimental situations.en_US
dc.publisherUniversity of St Andrews
dc.rightsCreative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported
dc.subjectParticle plasmonen_US
dc.subjectOptical trappingen_US
dc.subjectMetal nanoparticlesen_US
dc.subjectRayleigh and Mie scatteringen_US
dc.subject.lcshLaser manipulation (Nuclear physics)en_US
dc.subject.lcshSurface plasmon resonanceen_US
dc.subject.lcshMetals--Optical propertiesen_US
dc.titlePlasmonic effects upon optical trapping of metal nanoparticlesen_US
dc.contributor.sponsorsdw - Stiftung der Deutschen Wirtschaft (Studienfoerderwerk Klaus Murmann)en_US
dc.type.qualificationnamePhD Doctor of Philosophyen_US
dc.publisher.institutionThe University of St Andrewsen_US

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