The effect of graded nanometal particles and their shape on the enhancement of nonlinear optical properties of oxide glasses

Abstract

In the optical and infrared spectral ranges, nanometal particles such as Au, Ag and Cu have large real and small imaginary dielectric constants, so they possess strong plasmon resonance frequencies and large local fields. Metal nanoparticles change the nonlinear optical properties of glasses. Third-order nonlinear susceptibilities χ(3) of composite glasses with ellipsoidal nanometal inclusions have been calculated using the T-matrix method. We have investigated the effect of the shape of nanometals on the nonlinear optical properties of oxide glasses. It was found that the results of our model and the experiment compare well and spherical metal nanoparticles change the nonlinear optical susceptibilities of glasses more than cylindrical (two dimensional) nanoparticles.It is shown that if nanometals are included in glasses as graded profiles, their figure of merit (FOM) increases significantly and hence makes them promising materials for photonic applications such as all-optical switching. The FOM of SiO2 has been found to be enhanced by a factor of 6–7 by the inclusion of graded Au and Cu nanoparticles.

Enhancement of nonlinear optical properties of compounds of silica glass and metallic nanoparticle

“…In this paper, results of the T-matrix method and the experimental ones for different composite glasses are compared well [8,31]. …”

“…By utilizing appropriate approximations, various methods for calculating effective dielectric constant can be found in refs [6][7][8][9][10]. Maxwell-Garnett formula is used for inhomogeneities of small volume fraction (VF) (lower than 0.1), and its potential approximations are often applicable [2,5,11].…”

Third-order nonlinearity of metal nanoparticles: Isolation of instantaneous and delayed contributions

“…It has been shown that for a randomly dispersed sample averaging over the three cartesian directions gives a good approximation for of average field. 17 Using this approximation and Eqs. (8) and (10), the average electric field hEi and the average displacement vector hDi in the composite material are given by…”

The effect of the electronic intersubband transitions of quantum dots on the linear and nonlinear optical properties of dot-matrix system

“…when the wavelengths corresponding to the optical transitions become much larger than the QD size, one can use the so called effective medium theories such as Maxwell-Garnett (MG) method. This method has been used extensively by authors in the calculation of effective linear and nonlinear optical properties of composite mediums consisting of random distribution of nano particle [44]. Tian et al [45] have used MG effective medium theory to study the optical properties of a nanoporous array in silicon.…”