Beam propagation modelling of the digital response in cosine S-bend waveguide branch

The crosstalk performance of cosine S-bend branch has been simulated using finite difference beam propagation method (FD-BPM) accomplished by BPMCAD. The simulation was done for TE mode at the operation wavelength of 1.55 μm. The overall crosstalk performance of the cosine S-bend is slightly higher compare to that of linear Y-branch. With the same opening branching angle, the waveguide separation of cosine S-bend branch is smaller than that of linear Y-branch. The waveguides gap can be reduced up to 33.2 %.