Unconventional Electromagnetic Scattering

Wednesday, April 13, 2011
7:00 PM
Free and open to the public

Electromagnetic scattering is a fundamental process widely used in ranging, imaging and spectroscopy applications, although it also constitutes a major source of loss and crosstalk in integrated photonics. In this talk, I will introduce the concept of photonic chiral edge states, through which electromagnetic waves are permitted to propagate only in a single direction and scattering is completely suppressed. Obstacles and disorder can no longer induce reflection, and 100% transmission is observed across seemingly-impassible perfectly-conducting barriers in numerical simulations. I will explain how such phenomena, analogous to chiral edge states in integer quantum Hall effects, can arise from magneto-optical photonic crystals. I will present microwave observations verifying the existence of these novel phenomena. The complete suppression of electromagnetic scattering also enables unusual opportunities in optomechanics, with the promising goal of nano-manipulation and assembly. I will also discuss piezoelectric fabrics based on multi-material multifunctional fibers that not only allow the control of electromagnetic scattering, but also create new ways of manipulating acoustic waves in sensing, actuation and imaging applications.

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Zheng Wang

Research Scientist
MIT Research Laboratory of Electronics