In the field of optical microscopy, it is well known that spatial resolution is limited by diffraction of light. There have been variously efforts to achieve resolution beyond diffraction limit. However, most previous methods rely on nonlinearities of fluorescence, and thus require high-intensity lasers or special labeling strategies. In 2011, a novel superresolution technique based on a dielectric microlens and simple bright field microscope was demonstrated. The scheme is unexpectedly simple, since neither labeling nor intense laser is necessary, while the resolution is significantly higher than diffraction limit. Nevertheless, the contrast of bright field microscope is poor. In this work, we combine a dielectric microlens along with confocal laser scanning microscopy to considerably enhance image contrast. By simply inserting a microsphere onto the sample, the resolution is undoubtedly better than diffraction limit of the objective. Meanwhile, the contrast exhibits almost one order of enhancement. Field of view and magnification of the microlens imaging system are also characterized. Comparing with bright field microscope, laser scanning confocal microscopy provides better contrast under this microslens assisted super-resolution scheme. Our finding will contribute to material science and biomedicine research.

Date Published: 9 March 2015
PDF: 5 pages
Proc. SPIE 9331, Single Molecule Spectroscopy and Superresolution Imaging VIII, 93310O (9 March 2015); doi: 10.1117/12.2078060

Published in SPIE Proceedings Vol. 9331:
Single Molecule Spectroscopy and Superresolution Imaging VIII
Jörg Enderlein; Ingo Gregor; Zygmunt Karol Gryczynski; Rainer Erdmann; Felix Koberling, Editor(s)