We have constructed a soft x-ray microscope based on laser High Harmonic Generation of XUV at 30 nm and demonstrated ultra-high resolution imaging of biological samples including neurons. We continue to advance the technology for imaging in the x-ray water window and towards single protein molecule imaging as a complementary technique to cryo-EM.
The project developed from initial Basic Technology programme funding. The x-rays are produced using ultra-fast laser technology together with high harmonic generation (HHG). Currently producing > 108 photons/s of coherent x-rays around 30 nm illuminate the sample. The beam quality and stability of the XUV is critical to the successful imaging and considerable effort has been devoted to achieving a reliable high-quality source. Starting with recording Mie type scattering and diffraction from a self-assembled layer of 200 nm latex beads, we now utilize the technique of ptychographic phase retrieval to image biological and material samples.