Cluster model of polarization upon reflection from metallic surfaces
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Authors
Baldwin, Craig Wesley
Subjects
Metallic clusters
Metallic reflectors
Micro particles
Finite systems
Polarization
Metallic reflectors
Micro particles
Finite systems
Polarization
Advisors
Biblarz, Oscar
Date of Issue
1991-12
Date
December 1991
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
Polarization of light due to metallic reflection is at best only partially explained by current models. A new model is proposed to account for this phenomenon involving "native clusters". These clusters are assumed to be an integral part of metallic bulk surfaces and to manifest their dielectric properties in the visible region. As index of refraction may be computed based on a pseudo-Brewster angle, that angle of incidence where the minimum perpendicular reflectance occurs. Next the model identifies the cluster-to-bulk surface area ratio of the material and formulates the contribution of reflection from these areas by utilizing the Fresnel equations. Reflectance from the remainder, the bulk-surface area, is computed by applying conventional metallic reflection techniques. By combining the two contributions of reflectance for angles of incidence from 0 to 90 degrees, reflectance curves are generated for gold, silver, nickel and aluminum. These calculations assume a wide-band radiating source of light. Although the magnitude of reflectance for the model showed some variance over the range of angles of incidence (within 10%), the curves are similar in shape. The minimum perpendicular reflectance and grazing angles in incidence are consistent with experimental findings. The computer surface ratio for each metal varies indirectly with the metals' normal reflectance value, as expected from the model. Spectral information on the complex index of refraction is included to infer probable cluster size.
Type
Thesis
Description
Series/Report No
Department
Department of Aeronautics and Astronautics
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
Funder
Format
60 p.
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.