Venkatraman Gopalan | Materials Science and Engineering at Penn State

Venkatraman Gopalan

Venkatraman Gopalan
Professor of Materials Science and Engineering
Associate Director, Center for Optical Technologies
N-212 Millennium Science Complex
(814) 865-2910
gopalan@matse.psu.edu
http://www.mri.psu.edu/Faculty/Gopalan/

Biographical Sketch:

Dr. Gopalan received his B.Tech. in Metallurgical Engineering from the Indian Institute of Technology, Chennai, in 1989, and his Ph.D. in Materials Science and Engineering from Cornell University in 1995. He was a postdoctoral scholar in the Electrical and Computer Engineering Department at the Carnegie Mellon University from 1995-1996, and was subsequently awarded a director funded postdoctoral fellowship at the Los Alamos National Laboratory, where he performed research on ferroelectrics and electro-optics till 1998.

He joined Pennsylvania State University as an assistant professor in December 1998, and became a full professor in 2007. He has been awarded the National Science Foundation CAEEER award (2000), Robert R. Coble Award from the American ceramics Society (2002), Corning Faculty fellowship in Ceramic Sciences (2004), National Research Council Faculty Fellowship (2004), Wilson award for excellence in research (2005), Eshbach Faculty Fellow at the Northwestern University (2007), Richard M. Fulrath award from the American ceramics Society (2009).

He is the associate director of the Center for Optical Technologies since 2003, has served on the editorial board of the Annual Reviews of Materials research since 2004, and served as the Chairman of the User Executive Committee for the Center for Nanophase Materials Science, Oak Ridge National Laboratory, in 2010-11. Gopalan has published over 150 papers, and has written five book chapters on ferroelectric complex oxides, nonlinear optics, optical metamaterials, and scanning probe microscopy.

Research Interests:

Optical materials
Electro-optics
Ultrafast nonlinear optics
Scanning probe microscopy
Near-field optical imaging
Ferroelectrics
Ferromagnets
Semiconductors
Photonic crystals structures
Electromagnetic wave modeling
Phenomenological modeling

Areas of Research:

Our research focuses on the science and technology of nonlinear optical materials. The work straddles materials science, physics, and optical engineering. We have three areas of current interest:

Multiferroics: Multiferroics are an exciting class of materials that have co-existing ferroelectricity and magnetism. To study the coupled dynamics of electrical and magnetic domains, we are performing real-time nonlinear optical probing with simultaneous measurement of coupled properties such as magnetoelectric effect, electro-optic and magneto-optic effects, hysteresis, and dielectric spectroscopy. The nanoscale structure of single domain walls is studied using scanning probe techniques such as piezoelectric force-, magnetic force-, nonlinear dielectric-, electric force- , and near-field scanning optical microscopies. Modeling tools include Ginzburg-Landau phenomenology, finite element method, and electromagnetic simulations.
Nonlinear optical devices: We are developing a new class of devices by integrating diverse optical functionalities, such as optical frequency conversion, beam steering, dynamic focusing, beam shaping and high-speed switching, on a single ferroelectric chip by microengineering ferroelectric domains into gratings, lenses, prisms, and other arbitrary shapes.
Hybrid semiconductor-metal-oxide nanostructures: In a recent breakthrough with Badding group (Chemistry), we have demonstrated microstructured silica optical fibers which contain hundreds of extreme aspect ratio (~105) semiconductor and metal-filled nanowires in a highly periodic array. We are currently characterizing light guiding and nonlinear optical responses of these hybrid fibers.

Experimental tools include ultrafast femtosecond lasers, electro-optics and fiber optics, scanning probe microscopies, dielectric and magnetic measurements, clean room, cryogenics, and simulations based on home-written MATLAB as well as commercial codes.

Technology Impacted By Research:

Multiferroics enable electrical control of magnetic devices, and vice versa, and dual electrical-magnetic storage media. Nonlinear optical devices are targeted for optical communications and infrared applications. The vision of hybrid semiconductor-metal-silica structures is all-fiber optoelectronics, where light generation, modulation and detection can be performed within a fiber.

Journal Articles and Publications:

V. Gopalan, D. B. Litvin, “New symmetries in crystals and handed structures,” Nature Materials , DOI: 10.1038/nmat2987 (2011). http://www.nature.com/nmat/journal/vaop/ncurrent/abs/nmat2987.html
J. R. Sparks, R. He, Noel Healy, M. Krishnamurthi, A. C. Peacock, P. J.A. Sazio, V. Gopalan, and J. V. Badding, “Low loss ZnSe Optical Fiber Waveguides,” Advanced Materials, 23, 1647-1651 (2011).
A. Vasudevarao, A. N. Morozovska, I. Grinberg, S. Bhattacharya, Y. Li, S. Jesse, P. Wu, K. Seal, S. Choudhury, E.A. Eliseev, S. Svechnikov, D. Lee, S. Phillpot, L.Q. Chen, A. M. Rappe, V. Gopalan and S.V. Kalinin, “Correlated polarization switching in the proximity of a 180 degree domain wall,” Phys. Rev. B. 82, 024111 (2010).
J. H. Lee, L. Fang, E. Vlahos, X. Ke, Y. W. Jung, L. Fitting Kourkoutis, J.W. Kim, P. Ryan, T. Heeg, M. Roeckerath, V. Goian, M. Bernhagen, R. Uecker, P. C. Hammel, K. M. Rabe, S. Kamba, J. Schubert, J. W. Freeland, D. A. Muller, C. J. Fennie, P. Schiffer, V. Gopalan, E. Johnston-Halperin & D. G. Schlom, “Creating a Strong Ferroelectric Ferromagnet via Spin-Phonon Coupling,” Nature 466, 954 (2010).
I. A. Temnykh, N. F. Baril, Z. Liu, J. V. Badding, V. Gopalan, “Optical multistability in a silicon-core silica-cladding fiber,” Optics Express, 18, 5305-5313 (2010).