Third order optical nonlinearities in ZnFe2O4 nanocrystals

Abstract Using Z -scan method with picosecond laser at 532 nm, the third order optical nonlinearities of ZnFe 2 O 4 were investigated. The nonlinear refractive index is positive for all ZnFe 2 O 4 samples and decrease with the nanocrystal size. The nonlinear absorption dominated by saturable absorption for 19 nm and 11 nm ZnFe 2 O 4 but by two photon absorption for 5 nm ZnFe 2 O 4 organosol. Origin of the optical nonlinearities and the size effect has been discussed.