Multiple and Extended References in Fourier Transform Holography

The Fourier Transform Holography (FTH) in the range of soft X- rays is a fast growing research field supported by the development of Free Electron Lasers (FEL). In the conventional FTH with only one pinhole as reference, the signal intensity is very weak when it comes to measurements on a very short time scale. Fortunately, the high transverse coherence of the FEL- beam enables the creation of expanded reference structures leading to a high signal intensity in a short exposure time. In this thesis two expanded reference structures are investigated, the multiple and the extended reference structure. The former reference structure is a combination of many separate pinholes, whereas the latter one can have any shape in combination with at least one corner. As a representative for the multiple reference structure the Uniformly Redundant Array and for the extended reference structure the HERALDO-Pattern, standing for Fourier Transform Holography with Extended Reference by Autocorrelation Linear Differential Operation, are introduced. Both reference patterns are promising candidates for future soft X-ray FTH-experiments, especially for femtosecond time resolved imaging.

Autorentext

born in 1978, received his Diploma with main focus in theoretical solid state physics at the TU-Berlin in 2006. In 2010 he obtained his doctorate degree at the HZB. While accomplishing his PhD in soft X-ray FTH, he gained inside in SEM/FIB-preparation, in XA/XE-spectroscopy and in femtosecond time-resolved imaging at the FEL facility FLASH.