Modeling multimode-input star couplers in polymers

In this paper, we present the first numerical study of highly multimode-input integrated-optic star couplers. Although the design utilizes the physical quantities appropriate for a polymer device, many of the results are applicable to multimode-input star couplers using a wide range of materials. Design parameters explored include the input-port waveguide width, refractive index difference, and insertion angle. The simulation work is done utilizing the beam propagation method. The statistically based scaling parameters for these highly multimode structures are shown to be compatible with the results of an analytical model which is suitable for initial device design.