Broadband and High Extinction Ratio Mode Converter Using the Tapered Hybrid Plasmonic Waveguide

• Main Authors: Zhuo Cheng, Jun Wang, Zeyuan Yang, Haiying Yin, Wei Wang, Yongqing Huang, Xiaomin Ren
• Format: Article
• Language: English
• Published: IEEE 2019-01-01
• Series: IEEE Photonics Journal
• Subjects: Mode converter; hybrid plasmonic waveguide; TE<inline-formula xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <tex-math notation="LaTeX">$_{0}$</tex-math> </inline-formula>-to-TM<inline-formula xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <tex-math notation="LaTeX">$_{1}$</tex-math> </inline-formula>
• Online Access: https://ieeexplore.ieee.org/document/8723578/

We propose and numerically analyze a broadband and high extinction ratio mode converter to achieve the mode conversion between the fundamental transverse electric mode (TE₀) and the first-order transverse magnetic mode (TM₁). The mode converter is achieved by using the tapered hybrid plasmonic waveguide which the metal is directly covered on the Si waveguide without a thin low-index layer. After optimizing the structure of the tapered hybrid plasmonic waveguide, a wide operation bandwidth of 100 nm is obtained with the extinction ratio of the TM₁ mode and TE₀ mode larger than 20 dB in the output Si waveguide for the forward propagation. And for the back propagation, the operation bandwidth over 65 nm is obtained with the extinction ratio larger than 20 dB in the output Si waveguide. The whole footprint of the mode converter is only 0.8 &#x00D7; 11 &#x03BC;m². Fabrication tolerance analysis is also demonstrated.