Associate Prof. Jiafu Wang

Invited Speech Title: Dispersion Engineering of Spoof Surface Plasmon Polaritons in Metamateirals and on Metasurfaces

Speaker's Bio:
Jiafu Wang is currently an Associate Professor with the College of Science, Airforce Engineering University, Xi’an, China. He received the Ph.D. degree from Airforce Engineering University, China, in 2010. Hewas honored as the Rising Star of Young Scientist of Shaanxi Province in 2015 and is the grantee of the San Qin Talent Subsidy of Shaanxi Province. His doctoral dissertation won the nomination of National Excellent Doctoral Dissertation in 2012, and Excellent Doctoral Dissertation of PLA in 2011. He was awarded the First Prize of Excellent Achievement in Natural Science by Ministry of Education (ranked 4th) in 2012, the Second Prize for Excellent Teaching Achievement in Military Colleges in 2015 (ranked 4th). He was also awarded the Third-Class Merit each in 2004, 2007 and 2009. He has authored or co-authored more than 160 SCI-indexed journal papers, 21 as the first author and 34 as the corresponding author. He published 1 monographon metamaterial stealth technologiesMetamaterial Design and Its Applications to Stealth Technologies(Science Press, 2013).He is the Principal Investigator (PI) of more than 10 scientific research projects, including 2 from the Natural Science Foundation of China.His research interests include mainly electromagnetic metamaterials, metasurfaces, spoof surface plasmonpolaritons (SSPP), radar stealthy materials and technologies, antennas, microwave components, etc.

Invited Speech Abstract:
Spoof surface plasmonpolariton (SSPP), as an analogue to surface plasmonpolariton at optical frequencies, is a sub-wavelength mode confined around the interfaces between artificially structured materials or surfaces. Metamaterials and metasurfaces, as emerging artificial materials and surfaces, are the most important means of exciting SSPP modes. The most typical characteristic of metamaterials/metasurfaces is that their constituent artificial structures are sub-wavelength, which enables them to intrinsically support the sub-wavelength SSPP mode. In addition to the attractive shorter wavelength, SSPP exhibits very rich and unique dispersion properties due to its nonlinear asymptotic dispersion curve lying below the light line. The dispersion curve of SSPP can be divided into two regions: the linear weakly-dispersive region with low loss and the nonlinear strongly-dispersive region with high dissipation loss. By deliberately engineering the two dispersion regions comprehensively, novel microwave devises can be devised with significantly disparate EM performances in two closely adjacent bands, such as EM windows with strong absorption out of band, low RCS antennas, etc. In this report, we firstly briefly introduce the design principles of metamaterials from the perspective of dipole polarization mechanisms in dielectrics physics. Based on the electric dipole model, the effective electric/magnetic susceptibility of metamaterials is obtained and the design methodology of metamaterials is summarized. On this basis, the dispersion of SSPP in metamaterials or on metasurfacesare analyzed using the cascaded dipole model. Finally, we present some typical application of dispersion engineering of SSPP, such as beam steering, polarization conversion, RCS reduction, etc.