In this way, and almost by chance, researchers at TU Wien developed a novel microscopy technique that allows the refractive index of biological samples to be measured at a resolution far below what conventional light microscopy theory would seem to allow. Their paper is published in the journal ACS Nano.

The trick behind resolution beyond the wavelength of light

What happens if you try to image two molecules whose separation is smaller than the wavelength of light? You will not see two distinct points, but a single blurred spot of light—the images of the two molecules overlap, no matter how precise the microscope is.