Silicon-on-insulator free-carrier injection modulators for the mid-infrared

• Main Authors: Nedeljkovic, Milos, Littlejohns, Callum George, Khokhar, Ali Z., Banakar, Mehdi, Cao, Wei, Penades, Jordi Soler, Tran, David T., Gardes, Frederic Y., Thomson, David J., Reed, Graham T., Wang, Hong, Mashanovich, Goran Z.
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2020
• Subjects: Engineering::Electrical and electronic engineering; Electromagnetic Wave Attenuation; Modulation
• Online Access: https://hdl.handle.net/10356/143567
• Institution: Nanyang Technological University

Experimental demonstrations of silicon-on-insulator waveguide-based free-carrier effect modulators operating at 3.8 μm are presented. PIN diodes are used to inject carriers into the waveguides, and are configured to (a) use free-carrier electroabsorption to create a variable optical attenuator with 34 dB modulation depth and (b) use free-carrier electrorefraction with the PIN diodes acting as phase shifters in a Mach-Zehnder interferometer, achieving a VπLπ of 0.052 V·mm and a DC modulation depth of 22 dB. Modulation is demonstrated at data rates up to 125 Mbit/s.