Saturable Absorption in Suspensions of Single-Digit Detonation Nanodiamonds

Highly nonlinear optical properties of nanocarbon materials make them perspective candidates for saturable absorption (SA) applications, characterized by a short-term decrease in the optical medium absorption at high incident light intensity. The nonlinear optical properties and SA of aqueous suspensions of 5 nm detonation nanodiamonds (DNDs) have been studied by the z-scan technique under irradiation with nanosecond laser pulses at wavelengths of 532 and 1064 nm. The saturation intensity and nonlinear absorption coefficient describing the SA were obtained for concentrations of DND suspensions ranging between 0.5 and 5 wt %. It was concluded that the single-digit DND suspensions are suitable for optical limiting only at relatively high intensities of incident radiation, with saturation intensities of ∼5.9 and 14.1 MW/cm2 for 532 and 1064 nm incident excitation, respectively.