Enhanced Optical Modulation in Integrated Silicon Waveguides for the Near-Infrared

Abstract

Optics in the near-infrared has emerged as a key technology in the past several decades. The primary application has been the rapidly expanding demand for high-bandwidth communications. A challenge in adopting this technology has been the relative expense of optical components, which are typically fabricated in exotic material systems. The possibility of utilizing the relatively low-cost silicon material platform for integrated optics is therefore extremely attractive. However, several key challenges must first be addressed. One of the key components in optical systems are high-bandwidth optical modulators. For modulators that have been demonstrated in silicon so far, the performance is significantly inferior to the conventional material systems. Here, I present two approaches to improve EO modulation in silicon. One of them is by introducing some highly nonlinear organic material to the silicon device. The other approach is a novel reverse-biased PN junction geometry. While reverse-biased PN junction geometries have been used for modulation previously, the new proposed design will achieve substantial improvements over the state of the art. These two approaches both address the challenge of modulation in silicon, and are important steps towards making silicon a more attractive platform for optical system.