1 × 4 signal router using three

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 (LiNbO 3) 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. 1 Introduction Curvilinear directional couplers, branching and combining waveguides, S-shaped bend waveguides, and tapered wave-guides are indispensable components in constructing an integrated optical circuit. In practical directional couplers, however, light coupling in the S-shaped bend waveguide regions, in the front and rear of parallel waveguides, should be taken into account in order to evaluate the propagation characteristics precisely. Optical interferometer circuits, composed of optical couplers and optical delay parts, are a basic element employed in various optical devices. 1–3 Such circuits include Mach-Zehnder interferometers (MZIs), lattice-form filters (or cascaded MZIs), transversal-form filters, and interferometers with ring resonator filters.