Research Article
The Critical Adiabatic Linear Tapered Waveguide Combined with a Multimode Waveguide Coupler on an SOI Chip
Figure 8
When Wt/Wmmi is set at 0.35, the 1 × 1 MMI coupler with Wmmi = 4 μm/8 μm/12 μm achieves a minimum width of linear tapered waveguide at Wt = 1.4 μm/2.8 μm/4.2 μm, respectively. As the divergence angle θ of a linear tapered waveguide is scanning the range from 1° to 45° at a step of 1°, a maximum divergence angle θ = 16°/14°/8° is obtained under the constraint of ≥ 0.95, respectively.