Nonlinear Absorption and Ultrafast Dynamics of Ag Nanoparticle

Resonant nonlinear optical absorption of silver nanoparticles was studied experimentally via open aperture Z-scan using 130 fs, 400 nm laser pulses. Experimental results show that, at low intensity, can exhibit saturated absorption. While high it shows reverse The saturable is explained in terms ground state plasmon bleaching, while the believed to be from two-photon Saturable intensity and coefficient were obtained 1.3×1010 W/m2 3.3×10−10 m/W, respectively. energy relaxation process Ag after excitation pump-probe technique nm. demonstrated that included electron-phonon coupling with time constant τ1=(713±50) phonon-phonon τ2=(25.2±3) ps,