Enhanced short wave IR third order nonlinearity of gold nanoparticle embedded ZnO thin films

Gold nanoparticle embedded ZnO thin films have been studied at the fundamental and second harmonic wavelengths of a picosecond laser by Z-scan technique. The films exhibit the effect of saturable absorption and selfdefocusing. Large value third order nonlinear susceptibility (∼10 -8 esu) has been observed at 1064 nm. Fast relaxation time measurements have been performed with the diffraction of the probe beam with laser-induced transient grating technique. Figure of merit values for optical switching applications have been obtained. One of the samples has been tested for passive mode-locking applications in combination with the standard saturable absorber, IR26. © 2013 Optical Society of America.