  Fluorescence microscopy is indispensable in nanoscience and biological
sciences. The versatility of labeling target structures with fluorescent dyes
permits to visualize structure and function at a subcellular resolution with a
wide field of view. Due to the diffraction limit, conventional optical
microscopes are limited to resolving structures larger than 200 nm. The
resolution can be enhanced by near-field and far-field super-resolution
microscopy methods. Near-field methods typically have a limited field of view
and far-field methods are limited by the involved conventional optics. Here, we
introduce a combined high-resolution and wide-field fluorescence microscopy
method that improves the resolution of a conventional optical microscope by
exploiting correlations in speckle illumination through a randomly scattering
high-index medium: Speckle correlation resolution enhancement (SCORE). As a
test, we collect two-dimensional fluorescence images of 100-nm diameter
dye-doped nanospheres. We demonstrate a deconvolved resolution of 130 nm with a
field of view of 10 x 10 $\text{\mu m}^2$.
