Quasi-phase-matched high harmonic generation in structured plasmas

Structured plasmas are employed in order to realize the quasi-phase-matched generation of high harmonics. The plasma originates from laser ablated solids leading to the appearance of multiple separated jets. By altering the shape of the solid the dimensions of the plasma structure are easily optimized. Combining optimal jet widths and spacing the maximum enhancement of the harmonic intensity by a factor of 16 is observed after four plasma jets.