Microfluidic-based sources for efficient XUV generation and manipulation

Coherent sources of XUV and soft-x ray light based on high-order harmonic generation provide a key asset to ultrafast XUV spectroscopy and attosecond science. However, their exploitation is significantly hindered by the low generation efficiency, particularly when moving towards higher photon energies. This limit underlies the compelling challenge of exploring novel approaches. Here, we report on developing innovative sources for XUV and soft-x rays' generation and manipulation based on microfluidic devices realized through femtosecond laser micro-machining. By leveraging the microfluidic approach, we demonstrate the efficient generation of broadband harmonics spectra, up to 200 eV, from tailored gas media within a hollow waveguide. Furthermore, this integrated microfluidic approach allows controlling the spatial properties of the HHG beam through the direct manipulation of the waveguide’s modal characteristics, making it possible to generate high-brightness attosecond XUV and Soft-x ray pulses with unique polarization properties.