Lateral resolution enhancement of laser scanning microscopy by a higher-order radially polarized mode beam

We demonstrate that the lateral resolution of confocal laser scanning microscopy is dramatically improved by a higher-order radially polarized (HRP) beam with six concentric rings. This beam was generated simply by inserting liquid crystal devices in front of an objective lens. An HRP beam visualized aggregated 0.17 μm beads individually and is also applicable to biological imaging. This method can extend the capability of conventional laser scanning microscopes without modification of the system, with the exception of the addition of the liquid crystal devices in the optical path.