A very interesting effect in light propagation through a disordered system is Anderson
localization of light, this phenomenon emerges as the result of multiple scattering of
waves by electric inhomogeneities like spatial variations of index of refraction; as the
amount of scattering is increased, light propagation is converted from quasi-diffusive
to exponentially localized, with photons confined in a limited spatial region characterized
by a fundamental quantity known as localization length. Light localization is
strongly related to another interference phenomenon emerged from the multiple scattering
effect: the coherent backscattering effect. In multiple scattering of waves, in
fact, coherence is preserved in the backscattering direction and produces a reinforcement
of the field flux originating an observable peak in the backscattered intensity,
known as backscattering cone. The study of this peak provide quantitative information
about the transport properties of light in the material.
In this thesis we report a complete FDTD ab-initio study of light localization
and coherent backscattering. In particular, we consider a supercontinuum pulse impinging
on a sample composed of randomly positioned scatterers. We study coherent
backscattering by averaging over several realizations of the sample properties. We
study then the coherent backscattering cone properties as the relative permittivity of
the sample is changed, relating the latter with the light localization inside the sample.
We demonstrate important relationships between the width of the backscattering
cone and the localization length, which shows a linear proportionality in the strong localization regime.
| Identifer | oai:union.ndltd.org:kaust.edu.sa/oai:repository.kaust.edu.sa:10754/235651 |
| Date | 06 1900 |
| Creators | Delgado, Edgar |
| Contributors | Fratalocchi, Andrea, Ooi, Boon S., Bagci, Hakan |
| Source Sets | King Abdullah University of Science and Technology |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Rights | 2013-06-30, At the time of archiving, the student author of this thesis opted to temporarily restrict access to it. The full text of this thesis became available to the public after the expiration of the embargo on 2013-06-30. |
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