**Ting Zhang 1, Kan Li 2, Charankumar Godavarthi <sup>3</sup> and Yi Ruan 2,\***


Received: 16 August 2019; Accepted: 10 September 2019; Published: 12 September 2019

**Abstract:** Tomographic diffractive microscopy (TDM) is a label-free, far-field, super-resolution microscope. The significant difference between TDM and wide-field microscopy is that in TDM the sample is illuminated from various directions with a coherent collimated beam and the complex diffracted field is collected from many scattered angles. By utilizing inversion procedures, the permittivity/refractive index of investigated samples can be retrieved from the measured diffracted field to reconstruct the geometrical parameters of a sample. TDM opens up new opportunities to study biological samples and nano-structures and devices, which require resolution beyond the Rayleigh limit. In this review, we describe the principles and recent advancements of TDM and also give the perspectives of this fantastic microscopy technique.

**Keywords:** tomographic diffractive microscopy (TDM); diffracted field; holographic interferometry; inverse scattering
