Comunicazione
Femtosecond laser micromachining of integrated devices for XUV generation.
Barbato P., Crippa G., Ciriolo A.G., Devetta M., Vozzi C., Stagira S., Osellame R., Martinez V'azquez R.
Extreme ultraviolet radiation (XUV, $10\mbox{--}124 {eV}$) is at the core of the most advanced technologies for the in-depth study of matter, but the need for huge and expensive facilities to generate such high-energies photons limits its availability to few laboratories around the world. We propose a new kind of approach, based on integrated photonic, to generate and manipulate XUV radiation in a few-centimeter platform, consisting of a network of empty channels embedded in a glass sample. To realize this platform, we push beyond the limits of an extremely versatile micromachining technique called Femtosecond Laser Irradiation followed by Chemical Etching, which allows the realization of a 3D hollow core structure inside transparent materials. We demonstrated that these structures can host the interaction between a noble gas and a femtosecond laser beam, triggering high-order harmonic generation which ends up in the delivery of ultrashort XUV pulses, with a conversion efficiency of up to $10^{-5}$ in the $40\mbox{--}50 {eV}$ spectral region. This result represents the basis for the future development of a miniaturized and a highly efficient XUV source.