M.Sc.

        This thesis was including study the effect of different concentration (X=0.1,0.2,0.3,and 0.4), thickness, t (200-500)nm ,and substrate temperature ,T (300-393)K on the structural and electrical properties for CdXSe1-Xs  thin films ,which prepared by thermal evaporation on glass substrate under vacuum of (2 2 ×10 -5 mbar), and studying the mechanism of transition  for the d.c conductivity and a.c conductivity.

    Acousto-optics science deals with the interaction between sound and light waves. Acousto-optic waves are most important in transferring signals through the communication systems, since modulating signals takes a great advantages in the field of communication engineering, bio-medical, laser beam deflection and laser intensity modulation. The aim of this work is to simulate the fundamentals of an Acousto-Optic Modulator.

         A theoretical and computational investigation was carried out in the field of laser-plasma interaction using the Finite Difference Method to study the acceleration of electrons with non-relativistic elocities in a non-magnetized and magnetized collisionless plasmas.First, a (Nd:YAG) laser pulse of  25 fs duration and 5x10  intensity was assumed in the present study.When this laser pulse was allowed to nteract with a stationary electron in vacuum, it was found that the electron is accelerated during the interaction only and returns to stationary state af