Center for Functional Nanomaterials Seminar

Silicon is an attractive platform for the integration of optical components because of the mature infrastructure dedicated to the fabrication of silicon microelectronic devices. Furthermore, the silicon optical components can be readily integrated with transistors to form complex signal processing systems. At the wavelengths most relevant for optical communication (near 1550 nm), silicon has a high index and low inherent loss, making it an ideal material for compact devices. However, such compact devices also have large scattering loss. In addition, the electro-optic effects are weak in silicon, making it difficult to realize active components. This talk will describe techniques for fabricating low-loss silicon waveguides, low-power silicon PIN diode optical modulators, and high-performance silicon photodiodes using a CMOS IC process. The photodiodes exploit ion implantation damage to create midgap states that enhance sensitivity at the 1550 nm wavelength. These components are being developed for a high-speed optical sampling system that will be used to implement an analog-to-digital converter.