Nonlinear optical properties and markedly higher two photon absorption of ordered c-shaped plasmon-active metal nanostructures

Abstract Development of materials with highly nonlinear optical activity represents an intensively studied discipline due to potentially unique applications of such materials in photonics and information technologies. In this work the creation of ordered nanostructured arrays of c-shaped metals (Ag, Au, Al, and Pd) and characterization of their nonlinear optical properties are described. Large scale ordered arrays were created by the excimer laser pattering of a polymer surface and subsequent coating with Ag, Au, Al, and Pd. The successful creation of required structures was confirmed by the conductive AFM and FIB-SEM techniques. Linear optical response of the structures was examined using the UV–Vis technique and strong excitation of surface plasmon polariton resulting in appearance of strong absorption band was confirmed. The Z-scan technique with femtosecond laser pulses was used to determine the nonlinear optical response of the prepared metal arrays. It was found that the strong two-photon absorption appears under the illumination at the wavelength corresponding to the surface plasmon excitation. Extensive comparison with available literature data shows that the present structures exhibit markedly higher two-photon absorption activity.