839747.fig.003a
(a)
839747.fig.003b
(b)
839747.fig.003c
(c)
839747.fig.003d
(d)
Figure 3: Types of the possible nanocouplers realizations: (a) tapered waveguide coupler, (b) direct coupler transferring the power from a wide waveguide to a narrow waveguide, (c) lens coupler, (d) scatterer coupler.