Improving confocal microscopy resolution by tangentially polarized illumination and image subtraction

Confocal microscopy is widely used, but its resolution is limited. To improve confocal microscopy resolution, tangentially polarized illumination light and image subtraction are studied. Tangentially polarized light or vortex phase modulated tangentially polarized light are used as confocal microscopy illumination light. The effective point spread function difference of the confocal microscopy using tangentially polarized light and using vortex phase modulated tangentially polarized light is got first. The full width at half maximum of the point spread function difference is smaller. Simulation shows that the resolution of the confocal microscopy using tangentially polarized light illumination and image subtraction is increased by 19.9% compared with ordinary circularly polarized light. When compared with confocal microscopy using vortex phase modulated tangentially polarized light, simulation and fluorescence beads imaging experiment show that the resolution of the aforementioned confocal microscopy is improved by 13.6% and 11.2%. In conclusion, the resolution of confocal microscopy using tangentially polarized light illumination and image subtraction could be improved. Compared with other resolution enhancement technologies, this method is much simpler and does not need strong lasers.