70 Journal of Natural Sciences Research www.iiste.org ISSN 2224-3186 (Paper) ISSN 2225-0921 (Online) Vol.6, No.16, 2016 Second- harmonic generation improved of hybrid nanostructures Nadia Mohammed Jassim 1 , Nada Abdul Hadi Kareem 2 1 University of Diyala, College of Science, Department of Physics, Iraq. 2 University of qadissiya, College of Education, Department of Physics, Iraq Nadia Jassim@Sciences.uodiyala.edu.iq, Nada.almislimawy@qu.edu.iq Abstract We provide the synthesis and characterization of semiconductor nanowire attached with metallic nanoparticles. The wires consist of zinc sulfide (ZnS) attached with gold nanoparticles (Au NPs). The nonlinear optical properties of the semiconductor nanowires are combined with the plasmonic of metallic nanoparticles (Au NPs) and offer an improved optical signal in the near infrared spectral range. The plasmonic of a metallic (Au NPs) offers the effect of locally improving the electric field of the incident light on the nanowire and consequently inducing a much stronger second harmonic generation (SHG) signal. By comparing SHG signals measured from bare ZnS NWs and ZnS –Au hybrid nanostructures we obtain 6 time improvement of the SHG intensity It is demonstrated that is ZnS NWs is an ideal candidate for nanolasers, nanoprobes especially for the ultraviolet region, nonlinear optical microscopy and nanophotonic. Keywords: plasmonic nanostructures. Chemical synthesis, ZnS NWs, Second - Harmonic generation (SHG). 1. Introduction Nonlinear optical (NLO) harmonic generation play an important role in photonics[1], materials science[2] and bio sensing[3]. Second harmonic generation (SHG) is the lowest order frequency mixing nonlinear optical process where two photons create a single photon with half the incident wavelength [4]. This provides a convenient a practical means to obtain blue emission from a near- infrared laser. Practically, however NLO harmonic generation is generally inefficient at such a small scale. Plasmonic nanocavities are thus intriguing for the construction of more efficient coherent NLO light sources [5]. Surface-plasmon occurs, when light interacts with electron plasma waves at the metal surface. The electromagnetic field associated with these surface plasmons depends on the details of the nanostructure [6]. Localized surface-plasmon (LSP), in nanoparticle mediated emission has been proven as an efficient means to improve the quantum efficiency of light emitting devices [7] because of the strong coupling exciton effect between the surface-plasmons (SP) of the noble metal and the excitons of the semiconductors[8], the noble metal/semiconductor core/shell composite nanostructure has been one of the most promising composite nanostructures of the 21st century[9].Nanostructure plasmonic metal systems are known to greatly improve a variety of optical processes[10] including surface-plasmon enhanced photo catalysis, light-harvesting, and photo voltaic[11], surface-plasmon enhanced fluorescence[12], and forster resonance energy transfer[13], as well as the nonlinear optical properties of the semiconductors can be improved by the surface-plasmon[7], such as, second – and third- harmonic generation (SHG and THG)[ 14]. These have many potential uses in nanodevices for instance, nanolaser [15], and frequency doublers[16]. Semiconductor – metal hybrid nanostructures gives the basic information and improved optical properties on the optical coupling of the semiconductor and metal. Zinc sulfide (ZnS) is an important semiconductor with chemical stability and low brought to you by CORE View metadata, citation and similar papers at core.ac.uk provided by International Institute for Science, Technology and Education (IISTE): E-Journals