Extending the Photonics Toolbox with Plasmonic Super Absorbers and Active Optical Metamaterials

Koray Aydin
California Institute of Technology

Thursday, November 18, 2010 at 1:00pm
Engr IV Maxwell Room 57-124

Abstract

Controlling and probing the interactions of photons with nanoscale materials is a standing challenge due to the inherent optical diffraction limit and the restricted optical material parameter space. Plasmonic nanostructures and metamaterials are poised to revolutionize optical engineering by overcoming fundamental challenges in optical materials. Engineered nanophotonic materials hold substantial promise to impact applications in solar energy conversion, bio-chemical sensing and optical communications. In this seminar, I will first introduce ultrathin plasmonic super absorbers consisting of reflective metals and transparent dielectric and enabling broadband (400-750 nm), polarization-independent resonant light-absorption (~250 nm). Plasmonic super absorbers could find applications for light harvesting and photon management in photovoltaic and thermophotovoltaic cells. Then, I will present the first experimental demonstration of active infrared metamaterials composed of hybrid metal-vanadium dioxide (VO2) split-ring resonators. Drastic changes in the optical properties of VO2 with the phase transition enable control over the transmission and reflection properties of nanophotonic structures. Finally, I will introduce tunable, stretchable optical metamaterials that enable resonant line-width tuning and amplitude modulation of metamaterial and Fano resonances upon applying mechanical actuation to the polymeric metamaterial. This device the first mechanically tunable metamaterial in the near infrared, where modifying the distance between coupled resonator elements drastically changes the resonance frequency by a line-width (~400 nm). At the end, I will propose reconfigurable bio-sensors that relies on the active control of the metamaterial substrates for field-enhanced infrared absorption spectroscopy.

Biography

Koray Aydin is currently a postdoctoral research scholar in Applied Physics at California Institute of Technology. Dr. Aydin's research in the group of Harry Atwater has focused on the experimental and theoretical investigation of active plasmonic nanostructures and metamaterials and their applications in solar energy conversion and bio-sensing. He received his Ph.D. degree in Physics from the Department of Physics at Bilkent University, Ankara, Turkey under the supervision of Ekmel Ozbay. During his PhD, he investigated the novel electromagnetic phenomena, such as negative refraction, superlensing and enhanced transmission, in microwave metamaterials and photonic crystals. Dr. Aydin has authored more than 45 SCI-Index journal publications that are cited more than 1300 times. He is a member of the professional societies of OSA, APS, IEEE, MRS and SPIE and the recipient of 2007 SPIE Educational Scholarship.