Dynamically Modulating Plasmonic Field by Tuning the Spatial Frequency of Excitation Light

oleh: Sen Wang, Minghua Sun, Shanqin Wang, Maixia Fu, Jingwen He, Xing Li

Format: Article
Diterbitkan: MDPI AG 2020-07-01

Deskripsi

Based on the Fourier transform (FT) of surface plasmon polaritons (SPPs), the relation between the displacement of the plasmonic field and the spatial frequency of the excitation light is theoretically established. The SPPs’ field shifts transversally or longitudinally when the spatial frequency components <inline-formula> <math display="inline"> <semantics> <mrow> <msub> <mi>f</mi> <mi>x</mi> </msub> </mrow> </semantics> </math> </inline-formula> or <inline-formula> <math display="inline"> <semantics> <mrow> <msub> <mi>f</mi> <mi>y</mi> </msub> </mrow> </semantics> </math> </inline-formula> are correspondingly changed. The SPPs’ focus and vortex field can be precisely located at the desired position by choosing the appropriate spatial frequency. Simulation results are in good agreement with the theoretical analyses. Dynamically tailoring the plasmonic field based on the spatial frequency modulation can find potential applications in microparticle manipulation and angular multiplexed SPP focusing and propagation.