Guiding of high-intensity laser pulses in 100-mm-long hydrodynamic optical-field-ionized plasma channels
Hydrodynamic optically-field-ionized (HOFI) plasma channels up to 100 mm long are investigated. Optical guiding is demonstrated of laser pulses with a peak input intensity of 6 ×1017 Wcm -2 through 100 mm long plasma channels with on-axis densities measured interferometrically to be as low as ne 0=(1.0 ±0.3 )×1017 cm-3 . Guiding is also observed at lower axial densities, which are inferred from magneto-hydrodynamic simulations to be approximately 7 ×1016 cm-3 . Measurements of the power attenuation lengths of the channels are shown to be in good agreement with those calculated from the measured transverse electron density profiles. To our knowledge, the plasma channels investigated in this work are the longest, and have the lowest on-axis density, of any free-standing waveguide demonstrated to guide laser pulses with intensities above >1 017 Wcm -2 .