Holographic Ordering of Nanoparticles for Nanophotonics

Photonic bandgap structures consisting of ordered nanoparticles and/or liquid crystals periodically aligned within an organic host can be used to control light. For example, a polymer containing periodic regions with embedded nanoparticles provides a periodic refractive index profile, and thus creates a diffraction grating. Our collaborative efforts under the AFOSR DURINT program on polymeric nanophotonics and nanoelectronics has shown that optical interference-based patterning of a photosensitizer containing nanoparticles can create such a structure. Hybrid nanophotonic materials consisting of nanoparticles and/or liquid crystals distributed within a polymeric matrix will be the focus of this talk. These hybrid materials allow us to combine the flexibility and ease of fabrication of organic materials with the stability and long device lifetimes associated with inorganic nanoparticles. The nanoparticles range from semiconducting nanoparticles, such as Si, InP, and GaP, to metallic nanoparticles.

This talk will begin with a brief introduction to interferometry as a method for the rapid production of periodic structures that serve as photonic bandgap materials. Typical resulting structures containing nanoparticles will be presented to demonstrate the success of this interferometric technique. This will be followed by an overview of the optically active semiconductor nanoparticles and, where pertinent, their associated CW and time-resolved optical characterization. Studies of the movement of the nanoparticles within the matrix will also be presented. Finally, example applications of these hybrid materials and structures will be presented.

Periodic Structure of Gold Nanoparticles written using the Holographic Technique

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Speaker Biography:

Alexander N. Cartwright is an Associate Professor of Electrical Engineering, Director of the Institute for Lasers, Photonics and Biophotonics at the University at Buffalo (UB), and Co-Director of the Electronics Packaging Laboratory at the UB. In 1998, he received a NSF CAREER Award that supported his research on GaN based optoelectronic devices and his educational activities. In 2000, he was awarded a Department of Defense Young Investigator Award for research in piezoelectricity in III-N materials. Dr. Cartwright’s research is focused on III-N materials, quantum dot materials, optical non-destructive testing of stress and strain for device reliability, nanophotonics and nanoelectronics.