Spatial distribution clamping of discrete spatial solitons due to three   photon absorption in AlGaAs waveguide arrays
  We observe clamping of the output spatial light distribution of a waveguide array. Using a chirped pulse amplifier we reach peak intensities in the waveguides of ~24 GW/cm2. At this level, three photon absorption in the AlGaAs material clamps the discrete spatial soliton to a set distribution. Further increase in intensity does not change the distribution. 
Darren D. Hudson, J. Nathan Kutz, Thomas R. Schibli, Demetrios N.   Christodoulides, Roberto Morandotti, and Steven T. Cundiff
nlin.PS physics.optics