Probing Emergent Phenomena in Complex Oxides through Nonlinear Optics and Coherent X-rays

Abstract: The fast-paced improvements in ultrafast radiation from X-ray, ultraviolet, visible, and infrared to terahertz frequencies is enabling simultaneous probing of electron, phonon, and spin dynamics on the ps-to-ns time scales, as well as sub-micrometer length scales.   In this talk, I will present a brief introduction to nonlinear optics, followed by examples of the discovery of new low symmetry phases with large property enhancements in decades old ferroelectric crystals using nonlinear optical microscopy.  In a second example, I will show how an ultrafast laser pulse can create complex polar supertextures with modulation periodicities on tens of nanometers scale. 

Bio:  Gopalan received his PhD in Materials Science and Engineering at Cornell University in 1995.  After a brief stint as a postdoctoral scholar in the Electrical and Computer Engineering at the Carnegie Mellon University, he joined Los Alamos National Labs as Director-funded Postdoctoral fellow.  In 1999, he joined Pennsylvania State University as a tenure-track assistant professor, and became a full professor in 2008.  His interests are in symmetry, quantum materials, nonlinear optical imaging and spectroscopy, diffraction techniques, and optical device applications. He is the recipient of the NSF Career award, Robert R. Coble award and Richard M. Fulrath award both from the American Ceramics Society, the Faculty Scholar Medal from the Pennsylvania State University, and the IEEE UFFC Ferroelectrics Robert E. Newnham Award.  He is a Fellow of the American Physical Society and the American Ceramics Society.