Lensless Imaging Using Table-Top Soft X-Ray Lasers and High Harmonics Sources Reaching 70 nm Resolution

Abstract

A very promising high resolution imaging technique currently under rapid development is x-ray diffraction microscopy (or lensless imaging), in which a coherent x-ray diffraction pattern of a non-crystalline specimen is measured. In this technique, a sample is illuminated by coherent light, and the detailed scatter pattern is sampled at a rate higher than the Nyquist frequency. A computerized, iterative phase-retrival algorithm replaces the imaging optics, thus making it possible to reconstruct the image of the sample. Here we demonstrate soft x-ray diffraction microscopy with two complementary coherent soft x-ray sources- a capillary discharge soft x-ray laser at 47 nm [1] and a high harmonic generation source at 29 nm [2]. By using novel field curvature correction in the image reconstruction at high numerical aperture, we retrieve images with resolution as los was 70 nm using set-ups that fit on a 4′x8′ optical table- including both the soft x-ray source and the lensless microscope.