Pulsed laser deposition of nanocomposite thin films for photonic applications

Nanocomposite thin films formed by metal or semiconductor nanocrystals (NCs) embedded in a host exhibit interesting nonlinear optical properties related to the small size of the NCs (typically around 10 nn or below). These properties make these materials potential candidates for the development of all-optical switching devices. The challenge is to produce nanocomposite materials with controlled and suitable characteristics. The present work aims to show that nanocomposite materials produced by pulsed laser deposition (PLD) might have superior structural and non-linear optical properties than those obtained by other techniques. This result will be illustrated in systems formed by metallic NCs (Bi, Cu) embedded in an Al2O3 host. Fundamental aspects related to the nucleation and growth mechanisms or the reactivity of the NCs with the host will be discussed. Finally, the excellent nonlinear properties of the PLD synthesized composites will be illustrated in the case of Cu:Al2O3 films, in which the dependence of the nonlinear third order optical susceptibility (chi((3))) has been investigated as a function of the NCs size and chi((3)) values as large as 10(-7) esu have been achieved.