## 5 Discussion and Conclusions
Such values fit with that obtained usingother compact systems operating in the \"water window\" spectral range such as capillary discharge [101] and X-ray absorption spectroscopy [102], allowing to obtain a photon flux of \(\sim\)10\({}^{9}\) photons/s. The presented microscopes offer a superior spatial resolution to the visible light (optical) microscopes and, in contrast to other microscopy techniques such as SEM or TEM, do not require a preliminary special preparation of the samples to image. Although the spatial resolution achieved cannot compete with the SEM, it has to be taken into account that the EUV/SXR microscopes still operate using photons (with higher energy), instead of electrons. Thus, the photons-matter interaction allows obtaining different information from the sample, which can be integrated with the SEM one, based on electron-matter interaction. Moreover, despite the resolution of the presented microscopes is similar to that achievable with the stimulated emission depletion microscope (STED) in the visible light region [103], they allow the acquisition of full field images, contrary to STED systems, which operates in scanning mode, without the requirement of any fluorescence markers or staining, which modify the sample to be imaged. The resolution of the compact microscopes can be improved by employing a zone plate with a larger number of zones or by using high-repetition-rate lasers, to increase the photon flux on the sample plane and decrease the exposure time. The employment of a sub-pixel super-resolution camera in SXR represents also a solution to improve the actual achievements [62]. Moreover, the possibility to equip the presented full field microscopes with a cryo-stage, could make possible to image in vivo biological samples. In conclusion, the presented SXR and EUV compact microscopes, providing high optical contrast, can be employed as complementary imaging tools to already existing, well-established ones, providing additional information about the investigated samples. Such microscopes bring together remarkable factors, such as the desktop size, fast exposures, and nanometer spatial resolution, opening the possibility to establish partnerships in university and laboratories or companies, and multidisciplinary collaborations in a wide scientific environment. [PERSON] performed the EUV/SXR full field microscopy experiments, processed the data, and wrote the paper; [PERSON], [PERSON] conceived the experiments; [PERSON] designed the experiments, performed the measurements, and assisted in the preparation of the manuscript; [PERSON] designed and developed the gas-puff target source; [PERSON] and [PERSON] helped in the development of the whole equipment; [PERSON] also conceived the gas-puff target source. All authors have read and agreed to the published version of the manuscript. This research was funded by the National Science Centre, Poland under the Beethoven Programme, grant number 2016/23/G/ST/04319, and the European Union under the Horizon 2020 Programme Laserlab-Europe, grant number 871124. This work was supported also by the National Centre for Research and Development's, LIDER programme, Grant #LIDER/004/410(1-4/12/NCR/2013, and the National Science Centre, Opus programmes, Grant agreement numbers UMO-2015/17/B/ST7/03718, DEC-2011/03/D/ST2/00296 and UMO-2015/19/B/ST3/00435. The authors acknowledge also financial support from the EU FP7 Erasmus Mundus Joint Doctorate Program EXATIC under framework partnership agreement FPA-2012-0033, Ministry of Science and Higher Education of Poland and the European Commission's Seventh Framework Program (Laserlab Europe III--grant agreement 284464, Laserlab-Europe IV, grant agreement No. 654148 and COST Action MP601) European Economic Area (EEA) grants. This work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement no 871124 Laserlab-Europe.