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Photo-assisted polarization and photoinduced birrefringence in thin films containing azobenzene groups

Grant number: 08/04673-1
Support type:Regular Research Grants
Duration: December 01, 2008 - November 30, 2010
Field of knowledge:Physical Sciences and Mathematics - Physics - Condensed Matter Physics
Principal Investigator:José Alberto Giacometti
Grantee:José Alberto Giacometti
Home Institution: Faculdade de Ciências e Tecnologia (FCT). Universidade Estadual Paulista (UNESP). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil

Abstract

Measurements of the electro-optic activity and photo-induced birrefringence in films containing azobenzene groups will be performed varying various experimental parameters. The electro-optic activity in the films will be induced by means of the photo-assisted polarization technique and its value will be measured using a Mach-Zehnder interferometer and the birefringence will be induced by a linearly polarized light. Films with the azobenzene groups will be prepared employing different experimental techniques and their characterization will be performed using the UV-Vis and infrared spectroscopy techniques. The electro-optic and photo-induced birefringence measurements will be performed for different films and azobenzene molecules, films thickness, temperature, excitation light power and other experimental parameters. The photo-assisted and photo-induced measurements will be performed below the room temperature that were not frequently studied in literature. Such measurements will allow evaluating the dependence photo-isomerization and photo-assisted polarization processes on the free volume and results of orientation and relaxation processes on temperature will be analyzed with theoretical model and phenomenological equations. (AU)