253692.fig.008a
(a)
253692.fig.008b
(b)
Figure 8: The normalized real part of the longitudinal component of electric vector of low-index (1) and high-index (2) TM0 Bessel surface plasmon polariton versus the distance inside the 50 nm gold film separating the SF10 glass and air (a) or fluid with refractive index 1.33 (b). The distance from the Bessel surface plasmon polariton axis is , and the wavelength is .