953212.fig.003a
(a)
953212.fig.003b
(b)
953212.fig.003c
(c)
953212.fig.003d
(d)
Figure 3: Numerical simulation. (a) Refractive index of the simulated device. (b) The power flow distribution along the “Y coupler” without the particle. (c) and (d) The power flow distribution along the “Y coupler” waveguide while the gold nanoparticle ( 𝜎 = 3·107 [S/m]) is placed in the lower and upper part of the air gap, respectively.