Current research presents a visual-computational tool to design and investigate round electrostatic lenses in sense of analysis procedure. The finite elements methods is adopted to find the electrostatic potential in the lens region. Laplace’s equation is first replaced by a certain functional which physically represent the electric energy stored in the electric field. This functional is then minimized at each mesh point with respect to the nearest eight ones. This minimization process is proved to be entirely equivalent to solving Laplace’s equation. The requirement that the functional being minimized is then yields a set of nine point equations which inter relate the potentials at adjacent mesh points. Finally this set of equations is solved to find the electrostatic potential at each mesh point in the region of the lens under consideration. The procedure steps mention above are coded to program written in visual basic. Hence an interface tool for analyzing and designing electrostatic lenses has been built up. Designing results proved that the introduced tools has an excellent outputs in comparison with the others written in not visual programming languages. Furthermore it easier for researchers and designer to use such a tool over their counterpart ones.

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Multilayer antireflection coatings have been modeled in visible and infrared regions (1-5 μm) bands to increase the transmittance of glass and silicon substrates. The transmittance was studied using different semiconductor materials with different thickness ( single, double and three) layers to determine the best design that depends on the manufacture of antireflection coatings at low costs and few layers of coatings to reduce the stress generated by the increased number of layers. MgF2 and TiO2 materials are used in the visible region (300-1000 nm) at the central wavelength (500 nm). The transmittance of MgF2 single–layer with a quarter waves optical thickness is reached (98.61%) and the transmittance value is (98.74%) for arrangement (. The transmittance of the infrared spectrum for antireflection coating materials depends on the thickness and temperature of these materials because of scattering and absorption in such materials. LaF3, ZrO2, ZnSe, and CdTe materials are used in the infrared region at a design wavelength (3000 nm). The maximum value of transmittance is around (99.99%) for the best design that consisting of three layers with quarter wavelength thickness. Keywords: Antireflection Coatings, Multilayers, Semiconductor, Transmittance

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