Plasmon-Waveguide Resonances with Enhanced Figure of Merit and Their Potential for Anisotropic Biosensing in the Near Infrared Region

Figure 4

Spectral reflectivity of the guided modes in the CPWR configuration versus the reflectivity of conventional SPR without the SiO₂ dielectric layer for (a) TM polarization and (c) TE polarization. The incidence angle in (a) and (c) was tuned to 50.44°; (b) dispersion branch of the conventional SPR mode in a reduced region, showing the bending effect due to the prism dispersion. The arrows show the appearance of the LWSPR and SWSPR modes at 50.44° that correspond to the two dips shown in (a). (d) Full and opened diamonds show, respectively, the FWHM and FOM of the TM₀ mode whereas the filled and opened circles show the FWHM and FOM of the conventional SPR.

(a)

(b)

(c)

(d)