LEADER 00000nam  2200349   4500 
001    AAI3377397 
005    20120629111654.5 
008    120629s2009    ||||||||||||||||| ||eng d 
020    9781109382891 
035    (UMI)AAI3377397 
040    UMI|cUMI 
100 1  Schumann, Robert Paul 
245 10 Surface plasmon random scattering and related phenomena 
300    129 p 
500    Source: Dissertation Abstracts International, Volume: 70-
       09, Section: B, page: 5579 
500    Adviser: Stephen Gregory 
502    Thesis (Ph.D.)--University of Oregon, 2009 
520    Surface plasmon polaritons (SPPs) are collective electron 
       excitations with attendant electromagnetic fields which 
       propagate on a metal-dielectric interface. They behave, in
       many ways, as model two-dimensional electromagnetic waves.
       However, because the evanescent field of the SPPs extends 
       a short distance outside the interface, a near-field probe
       can modify the wave propagation. We use this behavior to 
       study both SPP scattering within the plane of the 
       interface and also the transition to free-space 
       propagation out of the plane 
520    We have, in particular, studied the multiple scattering of
       SPPs excited on rough silver films. Our laboratory 
       possesses apertureless near-field scanning optical 
       microscopes (A-NSOMs), the probes of which can act as an 
       in-plane scatterer of SPPs. Subsequent momentum-conserving
       decays of the SPPs generate an expanding hollow cone of 
       light to which information about the direction and phase 
       of the SPPs on the surface is transferred 
520    A focus of our studies has been SPP multiple scattering 
       when one of the scatterers (the tip) can move. This 
       problem is very closely related to a similar problem in 
       mesoscopic electronic transport, involving "universal 
       conductance fluctuations". It is also related to various 
       radar-detection, microwave communications and medical 
       imaging problems. In parallel with actual experimental 
       measurements, we have also conducted extensive Monte Carlo
       simulations of the scattering 
520    Multiple scattering leads to the appearance and detection 
       of "speckle" in the far field. A speckle field, however, 
       is more properly considered in terms of its embedded 
       optical vortices and so we have used holographic 
       techniques to study these. We have demonstrated that 
       vortices can be manipulated, created and destroyed by 
       movement of the STM probe tip 
520    Optical vortices are an example of the effect of 
       "geometric" or "topological" phase in physics and as such 
       link the trajectory of a parameter in one space to the 
       phase observed in another. In our case, the trajectory of 
       the A-NSOM tip parallel to the sample surface plane 
       generates topological phase in the far field, 
       manifestations of which are vortices 
590    School code: 0171 
650  4 Physics, Optics 
690    0752 
710 2  University of Oregon 
773 0  |tDissertation Abstracts International|g70-09B 
856 40 |uhttp://pqdd.sinica.edu.tw/twdaoapp/servlet/
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