Laser modification of optical properties of a carbon nanotube suspension in dimethylformamide

It is shown experimentally that a semitransparent suspension of multiwall carbon nanotubes (MWNTs) in $N$,$N$-dimethylformamide (DMF) is irreversibly bleached in a wide optical wavelength range in a field of nanosecond high-power laser radiation with a wavelength of 532 nm. The bleaching is accompanied by a sharp decrease in the nonlinear scattering; the suspension ceases to optically limit power. It is shown that the suspension is bleached due to light-induced chemical reactions between MWNTs and DMF molecules with formation of new hydrocarbon chemical bonds.