Optical Properties of Cu Nanocrystalline-OPAA Composite Film: Optical Properties of Cu Nanocrystalline-OPAA Composite Film

Optically transparent Cu nanocrystalline/OPAA composite film was successfully prepared by electrodepositing Cu into ordered porous anodic alumina (OPAA) template using constant voltage direct current technique. The morphology, structure, linear optical absorption, third-order optical nonlinearity and ultrafast dynamics of the Cu/OPAA composite were characterized by field emission scanning electron microscope (FESEM), transmission electron microscope (TEM). UV-Vis spectrophotometer, Z-scan technique and femtosecond pump-probe experiment. The results show that Cu nanoparicles have diameters of 40-50nm with face center cubic structure and disperse in the branched pores of the OPAA template, which induce a surface plasmon resonance (SPR) absorption at 584 nm. When the probe optical wavelength is far away from the SPR wavelength, Cu nanocrystalline/OPAA composite film possesses a character of light-induced absorption. When the probe optical wavelength is near the SPR wavelength, it possesses a photo-bleaching character. The composite film has a non-resonant third-order nonlinear susceptibility of 0.73x10(-9) esu and a response time of 1.3 ps.