%0 Generic
%A Schürmann, Martina
%D 2007
%F heidok:7785
%K Lochblenden , LichtleiterDigital In-Line Holography , Microscopy , DIHM , high resolution
%R 10.11588/heidok.00007785
%T Digital In-Line Holographic Microscopy with Various Wavelengths and Point Sources Applied to Static and Fluidic Specimens
%U https://archiv.ub.uni-heidelberg.de/volltextserver/7785/
%X Holography is a lensless imaging technique with intrinsic three-dimensional properties. Employing spherical waves enables the acquisition of magnified images. As the method in contrast to conventional microscopy does not require lenses, the achievable resolution only depends on the illumination wavelength and the solid detection angle. Approaching short wavelengths is thus advisable. In this thesis, 5.9, 2.9, 0.752, 0.500 and 0.356 µm polystyrene beads could be resolved. Furthermore, fibroblast cells with a diameter of about 100 µm and lithographic structures with random forms and shapes were imaged. By introducing an oil chamber with a higher refractive index into the setup, a significant increase of the numerical aperture and thus the achievable resolution was obtained. Nanosecond UV and synchrotron picosecond VUV radiation were proven to provide coherent illumination for in-line holographic microscopy measurements, enabling submicron resolution. First experiments in extending the method towards the fourth dimension included the tracking of tracer particles such as microspheres and oil droplets in flow channels. In addition to the commonly used pinholes, optical fibers were tested with respect to their suitability as alternative point sources. Due to their flexibility these sources could be used in complicated measurement geometries. Furthermore, their ability to be applied in situ makes them interesting for biological studies.