Seminar meets Fridays at 2:00 pm in Parker 328 unless otherwise noted.
2014 - 2015
Speaker: Junshan Lin
Title: Electromagnetic Field Enhancement for Metallic Nano-gaps
Abstract: There has been increasing interest in electromagnetic field enhancement and extraordinary optical transmission effect through subwavelength apertures in recent years, due to its significant potential applications in biological and chemical sensing, spectroscopy, terahertz semiconductor devices, etc. In this talk, I will present a quantitative analysis for the field enhancement when an electromagnetic wave passes through small metallic gaps. We focus on a particular configuration when there is extreme scale difference between the wavelength of the incident wave, the thickness of metal films, and the size of gap aperture. Based upon a rigorous study of the perfect electrical conductor model, we show that enormous electric field enhancement occurs inside the gap. Furthermore, the enhancement strength is proportional to ratio between the wavelength of the incident wave and the thickness of the metal film, which could exceed 10000 due to the scale difference between the two. On other hand, there is no significant magnetic field enhancement inside the gap. The ongoing work along this research direction will also be discussed.