Photonic crystal waveguide modulator with embedded p-n junction

Abstract

We demonstrate a photonic crystal (PhC) waveguide modulator based on a Mach-Zehnder Interferometer (MZI) configuration on a silicon-on-insulator (SOI) substrate. A p-n junction is embedded in the PhC waveguide such that the carrier concentrations in the waveguide can be changed with applied voltage, which changes the refractive index of the silicon material forming the waveguide. Our PhC waveguide is designed to work at 1550 nm. The slow light effect in the photonic crystal waveguide can enhance light-matter interaction, which helps to achieve sufficient modulation in a short interaction length around 100 micron, which may also help reduce the power consumption. Modulation speed of 8.5Gb/s has been measured.