Nanoantenna structures for the detection of phonons in nanocrystals

• Alexander G. Milekhin,
• Sergei A. Kuznetsov,
• Ilya A. Milekhin,
• Larisa L. Sveshnikova,
• Tatyana A. Duda,
• Ekaterina E. Rodyakina,
• Alexander V. Latyshev,
• Volodymyr M. Dzhagan and
• Dietrich R. T. Zahn

Beilstein J. Nanotechnol. 2018, 9, 2646–2656, doi:10.3762/bjnano.9.246

• itself is explained by the fact that the far field radiation that is scattered (re-emitted) by the nanoantenna array is summed from the dipole radiation of individual antennas, where a specific intensity per unit solid angle is governed by the classical formula [39]: where c is the speed of light and n

• is the unit radius vector directed from the nanoantenna to the observation point. The simulations were accomplished with the help of ANSYS EM Suite R18 software, wherein the regime of Floquet ports and periodic boundary conditions was employed to model the nanoantenna array as a uniform periodic

• medium supporting the nanoantenna array was assumed to fill semi-infinite space. This was implemented in ANSYS EM Suite by allowing the Si medium to touch one of the Floquet ports. In simulations, the procedure of adaptive meshing was accomplished at the highest frequency in the region of interest (3000

Nanoantenna-assisted plasmonic enhancement of IR absorption of vibrational modes of organic molecules

• Alexander G. Milekhin,
• Olga Cherkasova,
• Sergei A. Kuznetsov,
• Ilya A. Milekhin,
• Ekatherina E. Rodyakina,
• Alexander V. Latyshev,
• Sreetama Banerjee,
• Georgeta Salvan and
• Dietrich R. T. Zahn

Beilstein J. Nanotechnol. 2017, 8, 975–981, doi:10.3762/bjnano.8.99

• enhancement up to 1014 can be achieved. Although SEIRA is a relatively new tool for detection of organic and biological substances, it is found to be very effective for probing extremely low concentrations. Adato et al. demonstrated detection of 3 × 10−19 moles of silk protein for the entire nanoantenna array

• CoPc on nanoantenna arrays allows the homogeneity of the CoPc coverage on a nanoantenna array to be investigated using Raman mapping. The intensity of the C=N stretching mode at 1543 cm−1 was monitored. The Raman map obtained for a Au nanoantenna array with a 3 nm thick CoPc film shown in Figure 2b,c

• agrees well with the SEM image of the same structure. One can see from Figure 2c that the Raman mapping indicates the position of the nanoantennas by the stronger Raman (SERS) intensity (brighter regions), which reproduces the 5 µm periodicity of the nanoantenna array and evidences the homogeneous

Localized surface plasmons in structures with linear Au nanoantennas on a SiO₂/Si surface

• Ilya A. Milekhin,
• Sergei A. Kuznetsov,
• Ekaterina E. Rodyakina,
• Alexander G. Milekhin,
• Alexander V. Latyshev and
• Dietrich R. T. Zahn

Beilstein J. Nanotechnol. 2016, 7, 1519–1526, doi:10.3762/bjnano.7.145

• between plasmonic excitations of gold nanoantennas and optical phonons in SiO2 leads to the appearance of new plasmon–phonon modes observed in the infrared transmission spectra the frequencies of which are well predicted by the simulations. Keywords: nanoantenna array; localised surface plasmon resonance

• near the nanoantenna surface were numerically studied. To model the nanoantenna array as a uniform periodic structure, we exploited a regime of Floquet ports and periodic boundary conditions applied to the structure unit cell. The nanoantennas were considered to be supported by a thin SiO2 layer with a

• , 1400, and 1900 nm chosen for practical implementation were used in numerical simulations. The listed nanoantenna lengths (1400 and 1900 nm) secure the proximity of ther LSPR energy to the energy of optical phonons in SiO2. For the fixed structural parameters of the nanoantenna array, the simulations

Linear and nonlinear optical properties of hybrid metallic–dielectric plasmonic nanoantennas

• Mario Hentschel,
• Bernd Metzger,
• Bastian Knabe,
• Karsten Buse and
• Harald Giessen

Beilstein J. Nanotechnol. 2016, 7, 111–120, doi:10.3762/bjnano.7.13

• an artist’s impression in Figure 1. These materials can be fabricated as nanoparticles, either directly from a wet chemical process or by mechanical milling [71][72]. Another benefit afforded by the nanocrystal/nanoantenna array approach is as follows: As the nanoantenna array is inversion symmetric

• . Overall, the spectra demonstrate the excellent filling rate, manifesting itself in pronounced and reproducible spectral shifts in the linear response. Figure 4 shows the results of linear and nonlinear measurements with both a filled nanoantenna array and a nanoantenna array without filling

• , blue for the unfilled and in red for the filled antennas (SEM micrographs shown in Figure 5d). Figure 5e,f depicts the second harmonic emission spectrum of the two arrays. Yet again, the bare antenna array radiates second harmonic light, and the filled nanoantenna array produces a stronger signal