ECE / ITA Colloquium

  Dispersion control and active materials integration have yielded plasmonic components including i) three-dimensional single layer plasmonic metamaterials ii) all-optical, electro-optic and field effect modulation of plasmon propagation iii) plasmon-enhanced absorption in solar cells. We expand upon recently reported work on direct observation of two-dimensional negative refraction in the visible frequency range to develop a general approach to realization of three-dimensional single-layer, all-angle, polarization-independent plasmonic metamaterials exhibiting negative refraction.  Full wave simulations and dispersion calculations are used to demonstrate that metal-dielectric-metal plasmonic structures are characterized by negative wave vectors and negative refractive indices.  Metal-dielectric plasmon waveguides can serve as active switching elements when the dielectric refractive index can be actively modulated.  We demonstrate electro-optic refractive index modulation in metal-dielectric-metal plasmon waveguides using low-voltage electro-optic modulation of both silicon and perovskites oxide dielectric layers.  The efficiency and cost effectiveness of photovoltaic cells can both be increased by reduction of the active semiconductor absorber layer thickness and ability to fabricate ultrathin absorber layers opens up new possibilities for solar cell device design.  The strong mode localization of surface plasmon polaritons at metal-dielectric interfaces leads to strong absorption in semiconductors thin films, enabling a dramatic (10-100X)  reduction in the semiconductor absorber physical thickness needed to achieve an optically thick film.  Modal analysis in full wave simulation allows us to determine the fraction of power absorbed by the solar cell to be determined for both dielectric and plasmonic modes.

Harry Atwater is currently Howard Hughes Professor and Professor of Applied Physics and Materials Science at the California Institute of Technology.
  
  Atwater received his S.B. (1981), S.M. (1983), and Ph.D. (1987) in Electrical Engineering from the Massachusetts Institute of Technology.
  
  He currently serves as Director of Caltech’s Center for Science and Engineering of Materials (an NSF MRSEC; www.csem.caltech.edu), and is also Director of the Caltech Center for Sustainable Energy Research(www.ccser.caltech.edu ). Professor Atwater has consulted extensively for industry and government, and has actively served the materials community in various capacities, including Material Research Society Meeting Chair (1997), Materials Research Society President (2000), AVS Electronic Materials and Processing Division Chair (1999), and Board of Trustees of the Gordon Research Conferences. He was also Chair for the 2008 Gordon Research Conference on Plasmonics. He is also the founder of two companies focused on semiconductor film fabrication and solar energy, Aonex Technologies and Alta Devices.
  
  Atwater has been honored by awards including the Joop Los Fellowship from the Dutch Society for Fundamental Research on Matter, 2005; A.T. & T. Foundation Award, 1990; NSF Presidential Young Investigator Award, 1989; IBM Faculty Development Award, 1989-1990; Member, Bohmische Physical Society, 1990; IBM Postdoctoral Fellowship, 1987.
  
  Outside the science and technology world, his passion lies on the soccer field, and he enjoys coaching soccer teams for his sons, ages 14 and 10.