Fig. 1. AFM image of a spatially isolated silver nanorod. Inset left: Profiles of the particle taken along the white dashed lines. Inset right: Image of a representative silver nanorod cut from a transmission electron microscope-micrograph (its aspect ratio equals R ≃ 2). Note that the hight (short axis) of the imaged nanorod equals b = 25 nm.

Fig. 2. Scheme of the optical setup (MC: Mode converter, SF: Spatial filter, BS: Beam splitter, L: Lens, MO: Microscope objective, SC: (x,y)-scanning stage, S: Sample). Inset (I): Intensity profiles in the focal regime of the excitation beams focused on a glass-PVA interface: Linearly polarized Gaussian mode (LPGM), left; azimuthally polarized doughnut mode (APDM), center; radially polarized doughnut mode (RPDM), right. (a)-(c): x and y in-focus intensity cross-sections (continuous/dotted line) taken from the images (d)-(f), (d)-(f): (x, y)-plane in-focus intensity profiles, (g)-(i): (x, z)-plane intensity profiles. Inset (II): Intensity profiles of the parallel beam for the three different modes. Note that the polarization is indicated by arrows.

Fig. 3. CISM images of silver nanorods on a glass cover-slide covered by PVA and excited with an APDM (left) and a RPDM (right), respectively at 514 nm. (a), (b): Experimental data, the insets show the intensity profiles along the white dashed lines. (c), (d): Simulated data. Poissonian noise was added to account for the experimental conditions.

Fig. 4. CISM images of the same three silver nanorods (1,2,3) using an LPGM (a) and a APDM (c). Left column: Experimental data. Right column: Patterns reproduced by the fit algorithm based on Equations 7 (b) and 8 (d).

Fig. 5. CISM images of the same silver nanorod excited with an APDM. The sample is rotated from picture to picture by around 10. (a)-(c): Experimental data. (d)-(f): Fitted patterns reproduced by the model function defined in Eq. 8. To guide the eye the measured angle α _0,1,2 is indicated. (g): Plot of the measured angle α versus the adjusted angle α’.