Quantitative Surface Plasmon Interferometry via Upconversion Photoluminescence Mapping
Interference fringes dispersed along the -direction on Au squares with different incident angles. (a, b) Experimentally observed (a) and simulated (b) interference fringes supported by a ()μm2 Au square with different incident angles. (c) Schematic illustration for the excitation of SPPs on Au surface by an oblique TM laser. The incident light creates SPPs and a running wave of polarization (RWP). The interference between the SPP and the RWP forms fringes dispersed along the -direction. (d) Simulated intensity dispersion of interference along the -direction for different incident angles. (e) Simulated (red line) and experimentally observed (black square) spatial frequencies () for various incident angles. The simulated fringes reproduce the experiment results precisely. Scale bar: (a, b) 50 μm.