**7. Conclusions**

In this chapter the EUV table-top holographic imaging using a compact EUV laser as the illumination source was presented. The spatial resolution of the images of AFM tips, obtained by numerical reconstruction, was assessed utilizing a wavelet image decomposition and image correlation method leading to 164 nm. By increasing the numerical aperture of the recording and digitization wavelength-resolution EUV holograms were generated. The images were numerically reconstructed from the hologram recorded in surface of the photoresist and digitized with the AFM. Images of carbon nanotubes were obtained with 46±2 nm resolution determined by a knife edge test. Continuing development of highly coherent table-top EUV/SXR lasers in the vicinity of 10 nm (Wang et al., 2006) can be expected to enable future holographic imaging only limited by the photoresist resolution. Increasing flux of the EUV and SXR table top lasers opens a perspective in the future for single shot recording, permitting full field time resolved holographic imaging. This imaging method allows hologram recording without any previous object preparation, as required in electron microscopy, and free of any interaction with a probe that may occur in scanning microscopes. Photon based imaging systems also allow spectroscopic contrast, an important characteristic in imaging with shorter wavelength radiation. It also opens the possibility to study specimens in different environments, for example in the presence of external magnetic or electric fields. Moreover detailed processing of the reconstructed holographic images, performed by changing object-hologram distance in the reconstruction code was presented. It enables retrieving the depth information from a single high NA hologram. Using a specially fabricated 3-D object the numerical reconstruction and analysis of the hologram allowed to map the surface topography with a depth resolution close to 2 μm.
