scholarly journals Synthesis of silver nanostructure on gold nanoparticle using near field assisted second harmonic generation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Takashi Yatsui ◽  
Felix Brandenburg ◽  
Benjamin Leuschel ◽  
Olivier Soppera

AbstractBy using gold (Au) nanoparticles (NPs) as an optical near-field source under far-field illumination in combination with a silver (Ag) ion solution containing a photoinitiator, we coated Ag on Au NPs using a near-field (NF)-assisted process. We evaluated the change in the size of the NPs using transmission electron microscopy. Evaluation of the synthesized Ag volume over illumination power confirmed the squared power dependence of the NP volume with illumination using 808 nm light, i.e., a wavelength longer than the absorption edge wavelength of the photoinitiator molecules. The rate of volume increase was much lower than the plasmonic field enhancement effect. Therefore, the squared power dependency of the volume increase using a wavelength longer than the absorption edge wavelength originated from NF-assisted second-harmonic generation and the resulting excitation.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guang-Can Li ◽  
Dangyuan Lei ◽  
Meng Qiu ◽  
Wei Jin ◽  
Sheng Lan ◽  
...  

AbstractEfficient frequency up-conversion of coherent light at the nanoscale is highly demanded for a variety of modern photonic applications, but it remains challenging in nanophotonics. Surface second-order nonlinearity of noble metals can be significantly boosted up by plasmon-induced field enhancement, however the related far-field second-harmonic generation (SHG) may also be quenched in highly symmetric plasmonic nanostructures despite huge near-field amplification. Here, we demonstrate that the SHG from a single gold nanosphere is significantly enhanced when tightly coupled to a metal film, even in the absence of a plasmon resonance at the SH frequency. The light-induced electromagnetic asymmetry in the nanogap junction efficiently suppresses the cancelling of locally generated SHG fields and the SH emission is further amplified through preferential coupling to the bright, bonding dipolar resonance mode of the nanocavity. The far-field SHG conversion efficiency of up to $$3.56\times 10^{-7}$$ 3.56 × 1 0 − 7 W−1 is demonstrated from a single gold nanosphere of 100 nm diameter, two orders of magnitude higher than for complex double-resonant plasmonic nanostructures. Such highly efficient SHG from a metal nanocavity also constitutes an ultrasensitive nonlinear nanoprobe to map the distribution of longitudinal vectorial light fields in nanophotonic systems.


2018 ◽  
Vol 27 (01) ◽  
pp. 1850003 ◽  
Author(s):  
Mohamadreza Soltani

Here, we propose a novel plasmonic structure, called asymmetric plasmonic nanocavity grating (APNCG), which is shown to dramatically enhance nonlinear optical process of second harmonic generation (SHG). The proposed structure consists of two different metals on both sides of lithium niobate and a thin layer of graphene. By using two different metals the nonlinear susceptibility of the waveguide would be increased noticeably causing to increase SHG. On the other hand, it consists of two identical gratings on one side. By two identical gratings, the pump beam is coupled to two opposing SPP waves, which interfere with each other and result in SPP standing wave in the region between the two gratings. The distance between two gratings will be optimized to reach the highest SHG. It will be shown that by optimizing the geometry of proposed structure and using different metals, field enhancement in APNCG waveguides can result in large enhancement of SHG.


Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 848 ◽  
Author(s):  
Kanta Mochizuki ◽  
Mako Sugiura ◽  
Hirofumi Yogo ◽  
Stefan Lundgaard ◽  
Jingwen Hu ◽  
...  

Metasurfaces of gold (Au) nanoparticles on a SiO2-Si substrate were fabricated for the enhancement of second harmonic generation (SHG) using electron beam lithography and lift-off. Triangular Au nanoprisms which are non-centro-symmetric and support second-order nonlinearity were examined for SHG. The thickness of the SiO2 spacer is shown to be an effective parameter to tune for maximising SHG. Electrical field enhancement at the fundamental wavelength was shown to define the SHG intensity. Numerical modeling of light enhancement was verified by experimental measurements of SHG and reflectivity spectra at the normal incidence. At the plasmonic resonance, SHG is enhanced up to ∼3.5 × 103 times for the optimised conditions.


2011 ◽  
Vol 133 (40) ◽  
pp. 16317-16317 ◽  
Author(s):  
Hongping Wu ◽  
Shilie Pan ◽  
Kenneth R. Poeppelmeier ◽  
Hongyi Li ◽  
Dianzeng Jia ◽  
...  

1999 ◽  
Author(s):  
Anatoly V. Zayats ◽  
Igor I. Smolyaninov ◽  
Christopher C. Davis

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