Multi-slice ptychography with large numerical aperture multilayer Laue lenses

The highly convergent X-ray beam focused by multilayer Laue lenses with large numerical apertures is used as a three dimensional probe to image layered structures with an axial separation larger than the depth of focus. Instead of collecting weakly scattered high spatial frequency signals, the depth resolving power is purely provided by the intense central cone diverged from the focused beam. Using the multi-slice ptychography method combined with the on-the-fly scan scheme, two layers of nano-particles separated by 10 μm are successfully reconstructed with 8.1 nm lateral resolution and with a dwell time as low as 0.05 second per scan point. This approach obtains high resolution images with extended depth of field, which paves the way for multi-slice ptychography as a high throughput technique for high resolution 3D imaging of thick samples.