The intellectual merit of this project lies in the discovery that a chalcogenide glass exhibits spectacular reduction in the longitudinal elastic modulus with weak near-band-gap laser illumination. This phenomenon opens new areas of research along many fronts. The generality of the softening will be explored on a range of binary and ternary glasses to firmly establish the connection of photo-structural transformations to present theories of glasses and to understand electronic aspects of the new glassy state. We will investigate our finding that an electron beam can manipulate the agility of photo-softened glass towards creating novel photonic structures on the nano-scale. Combining the ability to modify the bonding in these covalent solids via low level light exposure with dimensional control offered by electron beams, presents technological opportunities to develop low-loss direct-write guided-wave structures, self-organized periodic structures, and high speed acousto-optical switches.
Broader Societal & Educational Impact The work proposed has broad implications since the physics underlying the rigidity of glasses extends to other systems of generic phases with anomalous properties adjacent to connectivity transitions in dilute electronic and molecular systems. Moreover, the discovery of new phenomena in glassy materials widely used in photonic and electronic applications, will impact information storage, memory applications, and the engineering of precision optics. The nano-scale electron beam patterning and self-organized features will set the stage for the development of chip scale photonic devices. The educational impact extends to training graduate students in an inter-disciplinary research program that overlaps Physics, Electrical Engineering and Chemistry. The PIs also guide outstanding undergraduates and under-represented students in research involving experimental, computational, and theoretical work as well as local high school students in summer projects. The educational component will also be enhanced by synergistic curriculum development. Such education and training activities within campus and in the community will continue to expand.
