TITLE:

Designing Al/dielectric metamaterials with hyperbolic dispersion

DATE:

Friday, February 05th, 2016

TIME:

3:30 PM

LOCATION:

GMCS 214

SPEAKER:

Prof. Lyuba Kuznetsova, Physics Department SDSU

ABSTRACT:

A special class of nano-layered hyperbolic metamaterials has received a lot of attention recently due to their unique optical property

namely that the dispersion of the dielectric constant for hyperbolic metamaterials exhibits a topological transition in the isofrequency surface from

an ellipsoid to a hyperboloid. The unique property of propagating waves in such a metamaterial is that the wavevectors have unbounded magnitudes

which allows dramatic increases of the photon density of states. The presence of these additional electromagnetic states allows modification of the

spontaneous emission rate. Exploring these effects with an Al/dielectric metamaterials could allow for an efficient integration into current

technology for potential use in label-free detection of organic and biological systems, and ultrafast LEDs.

This talk will cover a few concepts and materials systems that are promising for designing metamaterials with hyperbolic dispersion. In particular, I will discuss our recent work on the fabrication and characterization of nano-layered Al/dielectric metamaterials with a limited number of atomic size layers. I will talk about the theoretical modeling of the permittivity of the Al/dielectric nano-layered structures. I will introduce our recently developed method for analysis of spectroscopic ellipsometry data to extract the optical permittivity for this highly anisotropic metamaterial. This method maps the electromagnetic response using the dielectric tensor of a material. Finally, I will talk about our recent study of the “infinitely small” nanocavities and conclude with the possible directions for future work toward creating ultrafast LEDs and low threshold lasers.

HOST:

Dr. Jose Castillo

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