X-ray microscopy has proven its advantages for resolving nanoscale objects. High Harmonic Generation (HHG) sources allow performing nanoimaging experiments at the lab scale and their femtosecond pulse duration and synchrony to an optical laser renders them useful for studying dynamic processes. HHG sources regularly provide high average photon flux but relatively low single-shot flux limiting time-resolved applications to adiabatic processes. Here, we show that soft X-ray lasers (SXRL) in turn provide high flux due to an X-ray lasing transition, but the coherence of an SXRL operating in the amplified-spontaneous-emission scheme is limited. The coherence properties of an SXRL seeded by an HHG source can be significantly improved allowing single-shot nanoscale imaging. In combination with ptychography, source properties are measured with high fidelity. This is applied to study the plasma dynamics of SXRL amplification in unprecedented quality.
Imaging of biological specimen is one of the most important tools to investigate structures and functionalities in organic components. Improving the resolution of images into the nanometer range call for short wavelengths light sources and large aperture optics. Subsequently, the use of extreme ultraviolet light in the range of 2 nm to 5 nm provides high contrast and high resolution imaging, if it is combined with lensless imaging techniques. We describe important parameters for high resolution lensless imaging of biological samples and specify the required light source properties. To overcome radiation based damage of biological specimen, we discuss the concept of ghost imaging and describe a possible setup towards biological imaging in the extreme ultraviolet range.
We evaluated the capabilities of an intense ultrafast high-harmonic seeded soft X-ray laser at 32.8 nm wavelength regarding single-shot lensless imaging and ptychography. Additionally the wave front at the exit of the laser plasma amplifier is monitored in amplitude and phase using high resolution ptychography and backpropagation techniques.Characterizing the laser plasma amplifier performance depending on the arrival time of the seed pulse with respect to pump pulses provides insight into the light plasma interaction in the soft X-ray range.