Current Seminars

Tuesday, February 16, 2016
  • 4pm
  • Dow Science Complex 107
  • Dr. Stephen Rand, Department of Electrical Engineering and Computer Science, University of Michigan​
Magnetism at Optical Frequencies in Natural Materials
​Abstract: In optics, effects of the optical magnetic field are generally negligible at low intensities.  However in recent optical experiments intense magnetic light scattering has been observed as the result of a dynamic m​agneto-electric interaction that transcends the bounds of the multipole expansion.  The implications of this discovery for generating intense magnetic fields and converting solar energy to electricity with negligible heat generation will be discussed.
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Wednesday, February 17, 2016
  • ​2pm
  • Dow Science Complex 109
  • Dr. Roberto Merlin, University of Michigan
​​From Negative Refraction and Superfocusing to Wireless Power Transfer: The Path of the Superlens
​​Ernst Abbe published in 1873 a ground-breaking paper on the limit of resolution of an optical instrument, that was later rederived by Lord Rayleigh using Fourier analysis. The famous expression d = l/nsina relates d, the smallest separation that can be resolved, to the light wavelength l, the refractive index n and the angle of the cone of light that can enter the objective, 2a. The first part of the talk will take us from the late 1800's to the turn of the 20th century, when the field of near-field optics experienced a tremendous growth, emphasizing recent developments motivated by the work of John Pendry on negative refraction. We will also discuss how Abbe's result is related to Heisenberg's uncertainty principle and how the diffraction limit can be bypassed without violating any physical law.In the second part of the talk, the concept of near-field plates will be introduced. These are grating-like planar structures which rely on a hitherto unrecognized property of Maxwell's equations to provide focusing well beyond the diffraction limit, at arbitrary frequencies. The subwavelength electromagnetic-field distributions closely resemble those of slabs of negative-index material. The structures' design is related to that of the Fresnel plates in that diffraction forces the input field to converge to a spot on the focal plane. Unlike the conventional zone plates, for which focusing results from interference of traveling waves, the subwavelength plates control the near field and, as such, their superlensing properties originate from a static form of interference. Practical implementations of these plates hold promise for near-field data storage, non-contact sensing, imaging, nanolithography and, in particular, wireless power transfer applications. Experimental results demonstrating superfocusing and remote battery charging will be presented. 

Tuesday, February 23, 2016
  • 4pm
  • Dow Science Complex 107
  • Dr. Sukrit Mukhopadhyay, Senior Chemist, The Dow Chemical Company
​​Impact of Intermolecular Interactions on Optical Properties of Conjugated Molecules
Tuesday, March 29, 2016
  • 4pm
  • Dow Science Complex 107
  • Dr. Pengpeng Zhang, Department of Physics and Astronomy, Michigan State University
Title: TBA
Tuesday, April 12, 2016
  • 4pm
  • Dow Science Complex 107
  • Dr. Durdu Guney, Department of Electrical and Computer Engineering, Michigan Technological University
Title: TBA