  Efficient optical excitation of hybridized plasmon modes in nanoantennas is
vital to achieve many promising functionalities, but it can be challenging due
to a field-profile mismatch between the incident light and the hybrid mode. We
present a general approach for efficient hybrid-mode excitation by focusing the
incident light field in the basis of cylindrically polarized vector beams of
various higher-order spiral phases. Such basis vector beams are described in
the higher-order polarization states and Stokes parameters (both defined
locally in polar coordinates), and visualized correspondingly on the
higher-order Poincar\'e spheres. The focal field is formulated exclusively in
cylindrical coordinates as a series sum of all focused beams of the associated
high-order paraxial beams. Our focal field decomposition enables an analysis of
hybrid-mode excitation via higher-order vector beams, and thus yields a
straightforward design of effective mode-matching field profile in the tightly
focused region.

Optics