This paper presents an overview of integrated optical signal routing based on the principle of electro-optic effects. There are some specific types of materials whose refractive index changes due to the application of the electric field. Lithium-niobate (LiNbO3 ) and gallium arsenide are some important electro-optic materials. Due to the application of the voltage across electrode present in one of the arms of Mach-Zehnder interferometer (MZI), the electric field changes, hence, phase change in the signal present in one of the arms. Depending upon the phase change introduced, signal shifts from one waveguide to the other waveguide. Hence, this paper provides the detailed description of 1×4 signal router, using three MZI, and its construction using beam propagation method. Finally, the results are verified by the MATLAB-based results.