Synthesis of Second-Order Optical Nonlinearities with Electronic Metamaterials

University Of California-San Diego, La Jolla CA

Investigators

Abstract

Nontechnical description: The ongoing explosion in generation of big data relies on development of new information processing techniques and technologies that can compute and communicate large volumes of information with unprecedented speed. The current trend in achieving such performances depends on seamless integration of electronics and photonic (optical) technologies. However, the state of the art photonic technologies are costly, bulky, fragile in their alignment, and difficult to integrate with electronic systems, both in terms of cost effective manufacturing and in terms of delivery and retrieval of massive volumes of data that photonic circuits can process. To overcome these deficiencies, the current trend emphasizes the construction of photonic subsystems directly on an electronic processor chip, with the same manufacturing process as the surrounding electronics. Development of photonic materials with substantial nonlinear characteristics is essential for the construction of integrated, high speed photonic devices and systems for ultrafast information processing of big data. The project provides scientific training for students at graduate and undergraduate levels as well as serves as a platform for outreach, education and collaborative efforts with middle and high schools. Engagement of students of diverse ethnicity, gender and economic backgrounds in Science, Technology, Engineering and Mathematics (STEM) is enabled through various ongoing student and teacher training activities. Technical description: Optical materials with large second-order nonlinear susceptibilities are essential for the construction of integrated, CMOS compatible, high speed photonic devices for ultrafast on-chip modulation, switching and wave mixing of optical fields. Such nonlinear optical materials can be constructed by engineering the electronic band structure of semiconductors via either fixed charges at dielectric/semiconductor interfaces or gradient of work functions at metal/semiconductor interfaces. This project focuses on the design, fabrication and testing of nonlinear metamaterials, in free-space and guided wave configurations, for operation in the visible and near-IR regions. Additionally, relationships between the electrical and optical properties of the metamaterials are investigated in order to design electrically tuned optical nonlinearities for novel applications such as ultrafast switching. The overall goal of this project is to further advance nonlinear optical metamaterial science and technology, with focus on three specific approach objectives. The first objective focuses on theoretical analysis and modeling of metamaterials by engineering nanostructure composition exploiting various CMOS compatible materials; the second addresses development of nanofabrication methods of these metamaterials; lastly, the third objective targets experimental validation of the theoretical predictions and testing of the fabricated nonlinear metamaterials. This study also paves the way for development of numerous applications of metamaterials including modulation, switching, and wave mixing of optical fields. The PI continues to be committed to outreach, education and collaborative efforts within the university as well as with San Diego middle and high schools, through ongoing REU, RET and summer teaching programs.