Saturable absorption in aqueous suspensions of detonation nanodiamonds under irradiation with femtosecond laser pulses

The phenomenon of saturable absorption has been observed in aqueous suspensions of detonation nanodiamonds (DNDs) with 34, 50, and 110 nm sized clusters of nanoparticles under irradiation with 795-nm laser pulses of 120-fs duration. The saturable absorption intensity has been studied as a function of the DND concentration in suspension. At a concentration of 2 wt% of DNDs with 50-nm average cluster size, the saturable absorption intensity amounts to 950 GW/cm$^2$.