الفهرس 
Theoretical ConsiderationsOnly 14 pages are availabe for public view
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Abstract
Abstract The photoactive material is made up of a polymer containing light sensitive units (photoactive unit). These materials undergo a structural change when excited by ultraviolet or visible radiation, which in turn induces a physical change in the polymer. So it was very interesting to use these films in many applications, especially in integrated optics. This thesis is concerning with studying the optical properties of photoactive polymer films with different concentration of photoactive units, in particular the refractive index and the thickness. An introduction to photoactive polymer and its requirements, and theoretical considerations used for studying the optical properties of thin films are presented in chapter 1. Chapter 2 presents thin film preparation and experimental techniques used in this study. Also it presents an electronic fringe counter which used to measure the number of shifted fringes in our set-up. Chapter 3 introduces the basic elements for controlling stepper motor in our set-up, which, include power supply, I/O card, stepper motor driver, and the used computer program. In Chapter 4 theoretical equations are derived to calculate the refractive index and thickness of the prepared films, through changing the angle of incidence by using two different interferometric techniques, Michelson and Mach-Zehnder interferometer with automatic fringe counter. The results obtained using these techniques were found to be in good agreement. These interferometric techniques are limited in case of films doped with photoactive units more than 1%. This is due to the losses and scattering of laser beam, which, make the interference fringe pattern disappear. So to overcome this problem, we use a numerical method, which requires the measurements to be done at normal incidence of the transmission from two different thickness of a given thin film. A computer program is made to solve the numerical equations, which presented in chapter 5. Finally a conclusion and further work are given.