Download Spring 2006 Seminar Series

Spring 2006 Seminar Series
NEAR FIELD OPTICS OF PARTICLES ON SUBSTRATES
F. Moreno
Optics Group. Department of Applied Physics
University of Cantabria
39005 Santander. Cantabria. Spain
[email protected]
STATISTICS OF THE SCATTERED RADIATION FROM ENSEMBLES OF
PARTICLES IN VOLUME OR LOCATED ON SUBSTRATES
Francisco González
Grupo de Óptica. Dpto. Física Aplicada. Universidad de Cantabria
39005 Santander. Cantabria. Spain
[email protected]
Light scattering by particles on substrates has been a research topic of interest since long ago. This is because of the
applications of this type of scattering geometry in different fields like detection of surface contaminants, SERS,
biotechnology, nanophotonics, and others. The first part of this seminar will be given by Professor Moreno to present
the research conducted by the Optics Group in near field scattering by particulate surfaces. This will be complemented
with results about the generation of surface/localized plasmons by particles located on flat metallic/dielectric
substrates.
The second part of the seminar will be presented by Professor Gonzales to highlight the basic research on light
scattering by ensembles of particles (in free space or located on surfaces). This work is shown to be of interest in many
fields like cell inspection in biology, detection and monitoring of contaminants in the atmosphere and water or control
contamination in the semiconductor industry. One of the main interest of the researchers in this topic has been related
to the solution of the inverse problem, that is how to obtain information about the scattering system from the analysis
of the scattered radiation. Two different procedures are: 1) The analysis of the experimental scattering patterns. 2) The
analysis of the fluctuations of some property of the scattered radiation.
The main objective of the talk is to use the fluctuations of the intensity and polarization of the scattered radiation by
particle systems, in order to obtain information of the density, shape or optical properties of the particles. In the study
we use statistical parameters like the second moment of the scattered intensity, <I2>/<I>2 and the probability density
function of the cross-polarized intensity. We present results of particle systems consisting of isolated particles in
volume, particles located on substrates, and aggregates of particles (in which multiple scattering plays an important
role). Finally, we show experimental results of the fluctuations of the intensity of the scattered light obtained from
samples constituted by metallic particles located on conducting flat substrates.
This NECP Seminar is jointly sponsored by the Departments of Chemical and Materials Engineering,
Electrical and Computer Engineering, Mechanical Engineering, the NECP and the CeNSE.
Refreshments will be served starting at 3:15 pm.
Wednesday, March 22, 2005
CRMS 323
University of Kentucky, Lexington, KY
3:30 pm - 4:30 pm