Project Details
Description
Ferroelectric materials, which have a built-in electrical dipole moment in the absence of an external field, are making their way into our daily lives in countless ways. We find them in barcode readers in grocery checkouts, in high-speed electro-optic modulators and in other active elements that power our information superhighway. One of the most attractive features of this class of materials is that the material properties can be tailored by properly arranging the ferroelectric domain axis. Examples are non-linear optical devices that efficiently and selectively convert light from one wavelength to another by modulating the nonlinear optical properties by periodically changing (periodically poling) the ferroelectric axis. The feature sizes and periods of domain patterns in existing devices of this kind are limited, so far, to a minimum of a few microns. To develop nano-photonics devices that are more compact and offer both novel and higher functionalities, a new level of control of the ferroelectric domain orientation on the submicron and nanometer scale is required. This work addresses this major challenge by bringing together a multifaceted approach that includes solving basic science questions about the nano-scale domain wall structure and dynamics, developing new techniques for domain patterning using light and scanning probe microscopies, and demonstration of devices such as an optical parametric oscillator with backward nonlinear coupling, electro-optical Bragg reflector, and nonlinear photonic crystal devices. This international project is being carried out in collaboration among three groups in the US (Lehigh University, Pennsylvania State University State, and the University of Florida), the Applied Physics group (Prof. Sohler) at the University of Paderborn, Germany, and the Applied Optics Group (Prof. Buse) at the University of Bonn, Germany. Recent discoveries by this team have shown that the key to achieve smaller feature sizes lies in a detailed understanding of the structure and dynamics of the domain wall region and how they depend on atomic size defects. The project will explore these issues using a combination of theory and novel experimental tools for domain wall imaging and real-time characterization. Recent breakthroughs in laser-aided domain writing have shown that a delicate manipulation of these defects based on a sound understanding of the underlying processes can become a powerful novel tool for precise control of domain growth and nano-scale patterning. Education and outreach is a critical part of this collaboration. The undergraduate, graduate and post-doctoral scholars working in the PIs groups will acquire a unique perspective in interacting globally through travel exchanges and workshops involving all participating organizations. The team will hold annual workshops on advanced materials and their cutting edge technologies for K-12 through WISER and BEST programs as well as through the Lehigh Science Outreach program. This NSF project is co-funded by the Office of International Science and Engineering.
Status | Finished |
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Effective start/end date | 7/1/06 → 6/30/10 |
Funding
- National Science Foundation: $689,000.00