Fabrication of spatial transient-density structures as high-field plasma photonic devices

Fabrication of periodic transient-density structures in a gas jet with a boundary scale length approaching 10 μm was demonstrated. This was achieved by passing an ultrashort high-intensity laser pulse through a patterned mask and imaging the mask onto the target plane. Gas/plasma density at the laser-irradiated regions drops as a result of hydrodynamic expansion following ionization and heating by the laser pulse. The fabrication of gas/plasma density structures with such a scheme is an essential step in the development of plasma photonic devices for applications in high-field physics.