Optimum design of an optical waveguide: Determination of the branching angle of s-bend waveguides

In this paper, the authors introduce a new expression to describe the branching angle of an s-bend waveguide. This expression is useful for designing s-bend waveguides because of the difficulty of determining the branching angle of such a waveguide. The optimum value of the branching angle leads to the optimization of output power, which contributes to high performance levels of optical devices. The waveguide was designed with a device designing tool that uses the beam propagation method (BPM) in modeling the design. Mathematical expressions are used to characterize the branching angle based on the available waveguide design parameters. The waveguide design is also integrated into the optical network to ensure the design's compatibility with the network and to validate the overall performance of the optical device in the network. Based on the s-bend waveguide design, it has been found that its branching angle strongly depends on two parameters: the lateral offset of curve, h, and the length of the s-bend waveguide, L. The simulation results were analyzed to determine the optimum branching angle. The optimum value of the branching angle of the s-bend waveguide is 3.03 degrees, with a produced output power of 96.9%. With the support of the two parameters, h and L, the branching angle from the equation obtained in this study is helpful in designing waveguides to produce high-performance optical devices.