Third nonlinear optical properties of semiconductor PbS nanoparticles

The nonlinear optical properties of PbS nanoparticles were studied by the Z -scan technique with 50 ps pulse width, 530 nm and 1060 nm wavelengths from a mode-locked Nd: YAG laser. It is found that the sample shows a saturatio n absorption at 530 nm, and a two-photon absorption at 1060 nm. The optical limiting properties of PbS nanoparticles at these two wavelengths were als o studied.