Full-polarized tomographic diffraction microscopy achieves a resolution about one-fourth of the wavelength.

We present a marker-free microscope that records the phase, amplitude, and polarization state of the field diffracted by the sample for different illumination directions. The data are processed with an appropriate inversion method to yield the sample permittivity map. We observe that the full-polarized information ameliorates significantly the three-dimensional image of weakly scattering subdiffraction objects. A resolution about one-fourth of the illumination wavelength is experimentally demonstrated on complex samples.