Photo-Induced Optical Density in Poly(Methyl Methacrylate) /Brilliant oil scarlet BThin Films Abbas Sandouk 1 and Yousef T. Salman 2 1 Department of Electrical Power Engineering, Faculty of Mechanical and Electrical Engineering, Damascus University, Syria 2 Department of Physics, Faculty of Science, Damascus University, Syria Abstract: The photo-induced optical density of Brilliant oil scarlet /BPMMA thin films has been investigated using the pump-probe method. The results showed the dynamic evolution of the optical density where it increased rapidly in an exponential fashion, a photostationary state was reached and the relaxation phase decreased exponentially in a slow manner. Existence of the Angular Hole Burning (AHB) and the Angular Redistribution (AR) effects in the Brilliant oil scarlet Bmolecules in the PMMA polymeric host was proved. Finally, the results showed the behavior of the optical density as a function of the pump beam intensity of the Brilliant oil scarlet B/PMMA sample and the predominance of the photostationary state. Keywords: Photo-Induced, Optical Density, Photoisomerization, Angular Hole Burning (AHB), Angular Redistribution (AR), Brilliant oil scarlet B. 1. Introduction The photoinduced optical density (POD) in polymer/organic dye systems has been the subject of intensive investigations in the recent years. Materials with POD properties are very promising for use in many photonic applications [1-2], such as production of optical elements for polarization holographic [3-5], fabricating high quality aligning substrates[6-7] and molecular strain sensors for polymer films [8-11], etc. Research has centered on the potential applications of the polymers doped with azobenzene-based dyes [12].The studies performed on dichroic-dyes dispersed in polymer matrix predicted that it is a useful technique to enhance the optical response of the devices[13].The formation of such highly dichroic polarizing films may be used for the fabrication of anisotropic non-linear optical devices [14-17]. The assembly of organic molecules into polymeric thin films has potential applications for miniaturized optoelectronic devices [18-19]. The presence of azo groups in Brilliant oil scarlet Band their symmetry suggest the possibility of isomerization. Due to the highly anisotropic nature of azobenzenes, polarized light activates the photoisomerization in a selective manner [20].The photoisomerization induced in the azo-polymer leads to conformational changes in the polymer chains, which, in turn, leads to macroscopic variations in the chemical and physical properties of their surroundings and media. Incident light on an organic dye containing polymer induces an important property; photochemical trans →cis →trans isomerization [21].In Brilliant oil scarlet B/ PMMA thin film, photoisomerization activity is induced constantly and rapidly by polarized light through the excitation of the Brilliant oil scarlet Bdye molecules. This process results in a series of motions leading to optical density. Such phenomenon could be exploited in photonic applications [22]. International Journal of ChemTech Research CODEN (USA): IJCRGG ISSN: 0974-4290 Vol.8, No.12 pp 530-535, 2015