ZTE Communications ›› 2012, Vol. 10 ›› Issue (1): 34-39.

• Special Topic • Previous Articles     Next Articles

Design of a Silicon-Based High-Speed Plasmonic Modulator

Mu Xu, Jiayang Wu, Tao Wang, and Yikai Su   

  1. State Key Laboratory of Advanced Optical Communication Systems and Networks, Shanghai Jiaotong University, Shanghai 200240, P.R.China
  • Received:2011-11-30 Online:2012-03-25 Published:2012-03-25
  • About author:Mu Xu (xumu@sjtu.edu.cn) is master’s candidate at the State Key Laboratory of Advanced Optical Communication Systems and Networks, Shanghai Jiaotong University. He received his BS degree from the Department of Sophisticated Instruments and Optoelectronics Engineering, Tianjin University, in 2010. His research interests include silicon photonics and plasmonic photonics.

    Jiayang Wu (jiayangwu@sjtu.edu.cn) is a PhD candidate at the State Key Laboratory of Advanced Optical Communication Systems and Networks, Shanghai Jiaotong University. He received his BS degree in communication engineering from Xidian University in 2010. His research interests include silicon photonics and micro-fabrication technology of photonic devices.

    Tao Wang (wangtao2007@sjtu.edu.cn) is PhD candidate at the State Key Laboratory of Advanced Optical Communication Systems and Networks, Shanghai Jiaotong University. He received his BS degree in electronic engineering from the Department of Electronic Engineering, Shandong University, in 2004. He received his MS degree from the Chinese Academy of Sciences in 2007. His research interests include optical signal processing, silicon photonics, and micro-fabrication technology in photonic devices.

    Yikai Su (yikaisu@sjtu.edu.cn) received his BS degree from Hefei University of Technology, China, in 1991. He received his MS degree from Beijing University of Aeronautics and Astronautics (BUAA) in 1994 and his PhD degree in electronc engineering from Northwestern University, IL, in 2001. He worked for Bell Laboratories at Crawford Hill for three years before joining Shanghai Jiao Tong University, Shanghai, as a full professor in 2004. His research interests include optical signal processing in nano-photonic devices, ultra-fast signal transmission, and display optics. He has authored approximately 200 publications in international journals and conferences. He holds five US patents and has more than 20 US or Chinese patents pending.

Abstract: In this paper, we propose a silicon-based high-speed plasmonic modulator. The modulator has a double-layer structure with a 16 μm long metal-dielectric-metal plasmonic waveguide at the upper layer and two silicon single-mode waveguides at the bottom layer. The upper-layer plasmonic waveguide acts as a phase shifter and has a dielectric slot that is 30 nm wide. Two taper structures that have gradually varied widths are introduced at the bottom layer to convert the photonic mode into plasmonic-slot mode with improved coupling efficiency. For a modulator with two 1 μm-long mode couplers, simulation shows that there is an insertion loss of less than 11 dB and a half-wave voltage of 3.65 V. The modulation bandwidth of the proposed modulator can be more than 100 GHz without the carrier effect being a limiting factor in silicon. The fabrication process is also discussed, and the proposed design is shown to be feasible with a hybrid of CMOS and polymer technology.

Key words: plasmonic phase modulator, gradually varied taper, high speed