Abstract: Design and performance of a beam shaping device based on a simple flexible plastic fiber-bundle stripe and a prism duct is described in this study. Such a system offers practical means to modify and change the output beam shape and also provides quantitative information concerning the transmitted power. It is possible to measure transmitted power signal by using a precise photodetector and also analyze beam images taken by a digital camera. The photograph picture of the illuminating LED beam just at its output point shows a circular shape with a radius of about 4 mm and the fiber-bundle output beam is rectangular shape with a dimension of 22.5x2 mm. A regular duct is tested in this study and the optimum condition for the maximum power transmission and best image quality is reported in this study. The transmitted output power signals by the fiber bundle and prism duct are measured as a function of distance from each optical element. Using this system at the first beam shaping stage, the input circular beam with a diameter of about 10 mm is changed into a rectangular beam shape of 22x2 mm width and height by the fiber bundle. The power signal efficiency of about 64.86% is obtained for this stage. The rectangular beam is then changed into a square beam shape of 5 mm width at the second stage and the overall power signal efficiency of about 6.48% is obtained for this design.