A realistic approach for designing a single-mode Y-branch for weakly guiding material system using particle swarm algorithm

We designed and optimized a realistic single-mode Y-branch made of a relatively weakly guiding material system, with the aid of particle swarm algorithm combined with a 2D finite-difference time-domain solver. Design fabricability within a 1 mu m-resolution standard lithography was enforced. The proposed design has a mean total insertion loss of 0.45 dB over wavelengths ranging from 1450 to 1580 nm with a footprint of around 40 by 10 mu m. Finally, we investigated the effects of the structure's sidewalls angle on the fidelity of the simulation.