High-Speed GeSi Electroabsorption Modulator on the SOI Waveguide Platform

Following significant research and development work over the past few years, silicon photonics has become a promising candidate to provide low-power, low-cost, and high-speed photonic links for telecommunication, data communication, and interconnect applications. A high-speed optical modulator is one of the critical components for these links. In this paper, we report on our recent progress in the development of a GeSi electro-absorption (EA) modulator based on the Franz-Keldysh effect (FKE) integrated in a 3-μm silicon-on-insulator (SOI) platform. We first discuss the FKE in GeSi, and describe the EA modulator device design and fabrication. We then report on the performance of the fabricated device. Finally, we describe the monolithic integration of four modulators with a four channel wavelength division multiplexing (WDM) echelle grating to demonstrate a 112 Gbit/s (4 × 28 Gbit/s) WDM transmitter chip. This chip establishes silicon photonics as an enabling technology for low-power and low-cost data transmission applications.