Micro-optical nonlinearity of a silver oxide layer

We studied the near-field formation mechanism of a silver oxide thin film sandwiched between protective layers using a pump probe with nanosecond laser pulse irradiation and tapping-mode tuning-fork near-field scanning optical microscopy. A multilayer composed of ZnS–SiO2/Ag2O/ZnS–SiO2 showed abnormal optical nonlinear properties compared to ordinary third-order nonlinear materials. The Ag2O layer played a role in generating a strong light scattering center in a reversible chemical reaction in only a small area of the multilayer, and the optical near field produced about the scattering center was 40 times stronger than that produced by an antimony layer instead of Ag2O.