Digital in-line soft x-ray holography with element contrast

Abstract

Digital in-line soft x-ray holography (DIXH) was used to image immobilized polystyrene and iron oxide particles and to distinguish them based on their different x-ray absorption cross sections in the vicinity of the carbon K-absorption edge. The element-specific information from the resonant DIXH images was correlated with high-resolution scanning electron microscopy (SEM) pictures. We also present DIXH images of a cell nucleus and compare the contrast obtained for nuclear components with the appearance in optical microscopy.

A study on new approaches in coherent x-ray microscopy of biological specimens

“…down to about 0.3µm for systems with an x-ray/visible light converter [24] and to about 10 − 20 µm for direct illuminated CCD's [e.g. 48,121]. On the other hand, the Fresnel scaling theorem expressed in Eq.…”

X-ray holographic microscopy with zone plates applied to biological samples in the water window using 3rd harmonic radiation from the free-electron laser FLASH

“…Only the nucleolus (1) can be found in both images 3(e) and (f). As discussed in our previous study [32], such a difference can be explained by cellular components with similar optical properties for visible light, but either with a different material density or different chemical composition.…”

“…In this so-called water window, which is framed by the K-edges of carbon at 284 eV and oxygen at 540 eV respectively, the biologically relevant elements like potassium, calcium and carbon have a significantly shorter absorption length than water [31]. Due to this relative contrast the elemental distribution [32] and concentration within cells can be revealed. At the time of the experiment, FLASH was not yet capable of delivering radiation at fundamental wavelengths in the water window, and as such we used the 3rd harmonic (λ 3 = 2.68 nm) of the fundamental (λ = 8 nm) to explore this region.…”

Two and Three Dimensional Extreme Ultraviolet Holographic Imaging with a Nanometer Spatial Resolution

“…Femtosecond EUV radiation provided by the free-electron laser www.intechopen.com Two and Three Dimensional Extreme Ultraviolet Holographic Imaging with a Nanometer Spatial Resolution 307 FLASH was used for digital in-line holographic microscopy to image particles, diatoms and critical point dried fibroblast cells with 620 nm spatial resolution at 8 nm wavelength (Rosenhahn et al, 2009). Digital in-line SXR holography (DIXH) was used to image immobilized polystyrene and iron oxide particles with spatial resolution of 850 nm at wavelength range of 3.7-5.6 nm to take advantage of selective contrast in this wavelength range (Rosenhahn et al, 2008). Holographic measurement scheme to monitor the X-rayinduced explosion of microscopic objects was performed by a femtosecond time-delay X-ray holography, inspired by Newton's "dusty mirror" experiment, allowed to see the changes in EUV induced explosion of 140 nm diameter polystyrene beads (Chapman et al, 2007).…”