Label free nano-sensitive optical imaging beyond resolution limit of the imaging system

In this paper, we describe different approaches to improve resolution and get information about structure beyond the resolution limit of the imaging system. The approaches are based on collection of high spatial frequencies of the object using different techniques, including digital holography and spectral encoding of spatial frequency (SESF) approach. Synthetic aperture digital Fourier holography permits formation of the super-resolution images to extract microscopic information using wide field of view and long working distance low-numerical-aperture optics. SESF approach dramatically improves sensitivity to structural changes, up to nanoscale, and can form 2D and 3D nano-sensitive super-resolution images of highly scattering objects. Numerical simulation and experiments demonstrate advantages of these approaches.