Nanophotonics is a nascent research field which holds tremendous promise for control and manipulation of information in nanoscale dimensions and at high operating frequencies. A wide variety of novel Nanophotonic devices are being proposed and demonstrated by the research community. In this talk I will discuss my work on one class of devices known as Plasmonic Metasurfaces. These devices consist of an ultrathin (~30 nm) array of metal nanostructures fabricated by electron beam lithography on top of a substrate. The incident light excites resonant charge oscillations in metal nanostructures known as plasmons. These plasmons dramatically alter the propagation of light, and provide new insight into fundamental optical concepts such as Law of Refraction. In the latter part of my talk I will discuss my work on demonstrating tunable plasmonic resonances. Currently the resonant wavelength of plasmonic nanostructures is fixed by the material and structural parameters. The post-fabrication dynamic control is rather limited and remains a fundamental challenge. I will show that it is possible to use the highly tunable interband transitions in graphene to effectively control the plasmonic resonance. I will also describe a numerical approach to model graphene using full wave electromagnetic simulations. My simulations show excellent matching with experiments and point the direction for further optimization.
Naresh Emani graduated with MTech (Microelectronics) degree from IIT
Bombay in 2007. From 2007 to 2009 he worked in the area of CMOS
reliability as an engineer at TSMC, Taiwan. Subsequently he received his
PhD degree, specializing in Nanophotonics, from Purdue University in Dec
2014. In Jan 2015 he joined Data Storage Institute (A*STAR), where he is
currently working on demonstration of new on-chip light sources using
active dielectric nanoantennas.
Personal webpage: https://sites.google.com/site/nareshpurdue/home