© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 1 wileyonlinelibrary.com COMMUNICATION www.MaterialsViews.com www.advopticalmat.de achieve with the material on its own. In our case, a synergetic combination of a nanoporous plasmonic metal film and a sup- portive dielectric membrane formed a complex metal-dielectric assembly. This metal-dielectric host was then filled by a plas- monic metal nanorod guest with nanocarbon on top, resulting in a more complex host-guest configuration. Thermo-evapora- tion and electrochemical deposition technique enabled facile, yet precise fabrication without need for expensive nanofabrica- tion tools. The metal-dielectric assembly possessed significant unconventional nonlinearities induced by surface plasmon res- onance, which was further manipulated by the host-guest con- figuration. Finite element method (FEM) simulations provided theoretical support on the SPR-induced NLO effect. Our system combined cost-effective fabrication, well-controlled structural complexity, and highly tunable nonlinearity, therefore could be an emerging promising candidate for nonlinear optics. The SPR-modulated unconventional nonlinear optics was characterized using z-scan method with a femtosecond laser. Z-scan technique is a very convenient and sensitive characteri- zation method for third-order nonlinear optics. [19] Figure 1a pre- sents a schematic setup for open-aperture (OA) z-scan experi- ment. It measures the total transmission passing through the sample as a function of incident laser intensity, while the sample is gradually moved through the focus of a lens (along the z-axis). For closed-aperture (CA) z-scan setup (Figure S1), an aperture is placed in front of the (second) lens allowing only the central part of the light to be collected by the detector. The samples used in this work, namely porous anodic alumina (PAA) membrane, Au-PAA, Au-PAA-Au, and Au-PAA-Au-C 60 were fabricated as illustrated in Figure 1b. In specific, three metal-dielectric assembly samples (Au-PAA-8 min, Au-PAA-5 min, and Au-PAA-10 min, where Au and PAA represent for the metal and dielectric section respectively, while 8 min, 5 min, and 10 min indicate the duration for pores widening of the PAA prior to gold evaporation) were obtained by thermo-evap- oration method. Based on Au-PAA-8 min (Au-PAA in brief) samples, more complex host-guest configurations (e.g., Au- PAA-Au and Au-PAA-Au-C 60 ) were produced through electro- deposition method. For the metal-dielectric assembly samples, the metallic section is a nanoporous gold thin (110–120 nm) film while the dielectric section is a PAA membrane with hexagonally aligned cylindrical nanochannels (∼21 μm long). From Figure 1c, the mean diameter of the nanochannel was calculated to be approximately 76 nm for PAA-8 min. Thermo- evaporation of gold onto the membrane at an oblique angle of approximately 45° resulted in a unique and significantly sub- wavelength metal-dielectric assembly (Au-PAA). This complex assembly then served as a nano-host which incorporated other nano-guest to form more complex host-guest configuration. As shown in Figure 1c, Au-PAA-Au configuration was prepared Hybrid Plasmonic Nanostructures with Unconventional Nonlinear Optical Properties Yong Zhang,* Jing Jing Wang, Kyle E. Ballantine, Paul R. Eastham, and Werner J. Blau* Dr. Y. Zhang, K. E. Ballantine, Prof. P. R. Eastham, Prof. W. J. Blau School of Physics and Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) Trinity College Dublin Dublin 2, Ireland E-mail: zhangyo@tcd.ie; wblau@tcd.ie Dr. J. J. Wang Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin Dublin 2, Ireland DOI: 10.1002/adom.201300503 Nonlinear optical (NLO) materials play a central role in photo- nics and optoelectronics. Although much effort has been put in the development of new NLO materials, [1,2] there is still urgent need for novel highly nonlinear components. [3] For the past two decades, nanomaterials and nanostructures have become the focus of research in the field of nonlinear optics. Particularly, carbon-based nanomaterials have attracted much interest due to their rich structural variations including carbon black (CB), fullerene (e.g., C 60 ), carbon nanotube, and graphene. [4–6] In recent years, noble metal nanoparticles and their ordered nanostructures have shown fascinating properties as NLO materials thanks to their surface plasmon resonance (SPR)-induced optical effects. [3,7–11] SPR-induced optical effect is very sensitive to the constituent metal and dielectric environment and their relative arrangement. For instance, SPR-enhanced linear optical (LO) transmission has been reported in periodic hole arrays through a silver thin film. [9] Hybrid nanostructures provide an alternative route towards the development of novel NLO components. Compared with its individual constituents, hybrid nanostructures often show enhanced NLO effects and/or flexible processability. [12–18] Two types of hybrid nanostructures are currently attracting much interest. One is based on dispersion of single or multiple NLO components (e.g., organic dyes, quantum dots, carbon materials, and plasmonic metals) into a polymer matrix for flexible NLO thin films. [12,13] The other is fabricated through incorporation of at least two NLO components into one system for enhanced NLO effects. [14–18] Several synthetic methods including colloidal synthesis, [14] non-covalent/covalent binding, [15–17] and E-beam evaporation [18] have been developed for such incorporation pro- cess. However, there have been few reports on the fabrication and characterization of ordered hybrid nanostructures for NLO applications. Here we demonstrate that by employing an ordered com- bination of nanomaterials, the nonlinear optical response of the final structure can be tuned in a way that is impossible to Adv. Optical Mater. 2014, DOI: 10.1002/adom.201300503