Drastic increase in the second-order optical susceptibilities for monodisperse In2O3nanocrystals incorporated into PMMA matrices

I V Kityk, J Ebothé, Qingsheng Liu, Zhaoyong Sun, Jiye Fang
2006 Nanotechnology  
Using photoinduced second-order non-linear optical methods, we have determined that monodisperse In 2 O 3 nanocrystals of size ∼11-24 nm incorporated into poly(methyl methacrylate) (PMMA) matrices possess significant second-order optical susceptibilities up to 17 pm V −1 at λ = 1.76 µm; this is almost one order higher than that of traditional nanolayers of In 2 O 3 . A substantial increase in the corresponding susceptibilities is dependent on a relatively high monodispersion of the
more » ... of the nanocrystals. Calculations such as quantum chemical, molecular dynamics and band structure simulations of interfaces indicate that the principal role in the observed non-linear optical effects is played by interfaces on the borders separating the nanocrystals and the surrounding host polymer matrix. In order to clarify a role of the monodispersion and that of the surfaces, additional experiments were carried out using samples with a larger size-distribution of nanocrystals and highly polarized photopolymers of oligoethercrylates as the host matrix. A drastic decrease in the effective optical nonlinearity in these two cases further supports the crucial role of the nanointerfaces. (Some figures in this article are in colour only in the electronic version)
doi:10.1088/0957-4484/17/8/011 fatcat:5xjy2uy7mrdp5gzwd6pydsgh7e