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.
Wednesday, April 13, 2011
Free and open to the public