Investigation of nonlinear optical properties in bismuth nanospheres suspensions

Bismuth nanospheres with diameters below 100 nm were synthesized. Optical nonlinearities of Bi nanospheres suspensions have been investigated by Z-scan technique in the condition of non-resonant excitation with femtosecond laser, and the third order nonlinear refractive index was obtained for Bi nanospheres. These samples also exhibit optical limiting ability through the refraction optical limiting detection. The results indicate that the nonlinear absorption and scattering can be ignored for the solvent ethanol and the Bi nanospheres suspensions present obvious nonlinear refraction properties under the non-resonant femtosecond laser pulse excitation after excluded the nonlinear absorption and nonlinear scattering.