Superresolution imaging with focused radially polarized beam

Focused radially polarized beam is used to image non-fluorescent specimens to enhance the spatial resolution of conventional confocal microscopes.

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Summary

With pupil engineering of the common radially polarized illumination, a more tight focal spot can be obtained. Combining this character with a confocal laser scanning system, we can demonstrate both numerically and experimentally that this condition can offer spatial resolution improvements for imaging.

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Research description

Rigorous vectorial focusing theory is presented in this paper for imaging small
particles next to each otherwith a confocal laser scanning system.We consider radially polarized illumination with an optimized amplitude distribution and an annular lens to obtain a narrower spot size of the longitudinal component of the field in focus.

A polarization convertor at the detector side is added to transform radial polarization to linear polarization in order to make the signal detectable with a single mode fiber.

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