Super-Resolution Real Imaging in Microsphere-Assisted Microscopy

PLoS One. 2016 Oct 21;11(10):e0165194. doi: 10.1371/journal.pone.0165194. eCollection 2016.

Abstract

Microsphere-assisted microscopy has received a lot of attention recently due to its simplicity and its capability to surpass the diffraction limit. However, to date, sub-diffraction-limit features have only been observed in virtual images formed through the microspheres. We show that it is possible to form real, super-resolution images using high-refractive index microspheres. Also, we report on how changes to a microsphere's refractive index and size affect image formation and planes. The relationship between the focus position and the additional magnification factor is also investigated using experimental and theoretical methods. We demonstrate that such a real imaging mode, combined with the use of larger microspheres, can enlarge sub-diffraction-limit features up to 10 times that of wide-field microscopy's magnification with a field-of-view diameter of up to 9 μm.

MeSH terms

  • Microscopy / methods*
  • Microscopy, Atomic Force
  • Microspheres*

Grants and funding

We would like to thank the Hong Kong Research Grants Council (project codes CityU 11215614 and CityU 118513) and the City University of Hong Kong (project no. 9610216) for their financial support on this project. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.