Research Article
The Critical Adiabatic Linear Tapered Waveguide Combined with a Multimode Waveguide Coupler on an SOI Chip
Figure 4
This linear tapered waveguide with a divergence angle of 1° is combined with the three different widths of a 1 × 1 MMI coupler Wmmi of 4 μm/8 μm/12 μm with respect to the exact imaging lengths Lmmi of 28.7 μm/113.0 μm/257.2 μm. When Wt/Wmmi is set at above 0.35, the output power of a 1 × 1 MMI coupler combined with a linear tapered waveguide achieves above 0.95.