This research aims at the complex optical microstructures fabrication for optical films to provide a better backlighting module brightness. It utilizes UV lithography technology cooperated with Snell's law. When light pass through an optically transparent material, light deflection depends on the refraction index of the material. By using various transmission medium and changing the substrate inclination, the controllable complex optical microstructures can be fabricated. After being verified by the optical simulation, a 65deg micro-ridge array film can enhance optical brightness more than 50% (from 476 to 716 mcd). It will contribute the backlighting modules industry for liquid crystal display applications.