Optimized Design and Fabrication of a Directional Coupler for Improved Extinction Ratio and Fabrication Tolerance

초록

We designed and fabricated a directional coupler to get better extinction ratio and fabrication tolerance. Also, we propose a design concept of a directional coupler to improve the characteristics, such as extinction ratio and fabrication tolerance. The adoption of curved waveguide and a reverse lateral shift on an optimized coupling region provides better characteristics. The extinction ratio of an optimized directional coupler is improved to ~7.4 dB higher than a conventional one.