Depolarized Hyper-Rayleigh Scattering from Copper Nanoparticles

Abstract

In this paper we report the results of polarization resolved hyper-Rayleigh scattering measurements of copper nanoparticles of 5-55 nm size. The polar plot of polarization-resolved second harmonic intensity against polarization angle from the copper nanoparticles resembles the pattern seen from a dipolar source. The measured first hyperpolarizability values scale quadratically with the particle size, which implies that the second harmonic response from the copper nanoparticles results from symmetry breaking at the surface of the particle rather than in the bulk.

Selective Detection of Mercury (II) Ion Using Nonlinear Optical Properties of Gold Nanoparticles

“…As a result, the total nonlinear polarization consists of different contributions such as multipolar radiation of the harmonic energy of the excited dipole and possibly of higher multipoles, as we discussed in our previous publication or reported by others. 20,[24][25][26] The HRS intensity therefore also consists of several contributions. The first one is the electric dipole approximation, which may arise due to the defects in nanoparticle.…”

“…This contribution is very important when the size of the particle is no longer negligible when compared to the wavelength, as we reported before. 20,[24][25][26] Figure 2 shows how the HRS intensity varies after addition of different concentrations of Hg (II) into modified gold nanoparticle solution (12 nM). We observed a very distinct HRS intensity change (about 1.2 times) even after addition of 5 ppb Hg(II) as shown in Figure 2b.…”

“Small-particle limit” in the second harmonic generation from noble metal nanoparticles

“…At the molecular level, the contribution of the various dipolar, quadrupolar and retardation terms to the HRS intensity and their polarization angular distributions were worked out by Bersohn [8]. Recently, polarization-resolved hyper-Rayleigh measurements have been carried out by Brevet and his coworkers [9][10][11] on Au and Ag nanoparticles, and by us on Cu nanoparticles [12]. The data in all these experiments have been fitted nicely to the angular distribution expression suggested by Bersohn et al [8] for HRS from small molecules in solution.…”

Size and Shape Effect on Biomedical Applications of Nanomaterials

“…Non linear optical properties of nanostructured materials [16][17][18] can be useful in optoelectronics. Size and shape dependent properties of noble nanomaterials are resulting in the strong scattering and absorption of light [19][20][21] due to large optical field enhancement, however in semiconductors, due to the confinement of the electronic motion to a length scale that is comparable to or smaller than the length scale characterizing the electronic motion in bulk semiconducting material [22][23][24].…”