Subtraction imaging by the combination of higher-order vector beams for enhanced spatial resolution.

ABSTRACT

We demonstrate that the spatial resolution in confocal laser scanning microscopy is remarkably improved by simple image subtraction between images acquired by higher-order transverse modes of a cylindrical vector beam, referred to as radially and azimuthally polarized Laguerre-Gaussian mode beams. Two types of combinations of vector mode beams suitable for subtraction imaging are derived by a systematical study based on numerical calculations. The spatial resolution of about 100 nm is experimentally achieved without the degradation of image quality.