Periodic Index-Modulated Plasma Waveguide

We demonstrate a wire-obstructed cluster flow technique for making periodically modulated plasma waveguides in hydrogen, nitrogen, and argon with sharp, stable voids as short as 50 μm with a period as small as 200 μm. These gaps persist as the plasma expands for the full lifetime of the waveguide. We demonstrate guided propagation at intensities up to 2×10¹⁷ W/cm², limited by our laser energy currently available. This technique is useful for quasi-phase matching applications where index-modulated guides are superior to diameter modulated guides.