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

Abstract

Measurement of transient absorption of a sample allows estimation of the evolution of the nonlinear response of materials after excitation by a short pump pulse. In this work, the time dependent nonlinear response of silver nanoplatelets in water was measured using transient absorption technique for various volume fractions of silver in water. These measurements were carried out in subpicosecond time scales and a suitable theoretical model was developed. It is been shown that the hot-electron contribution to the third-order nonlinearity of metal colloids is much higher than its instantaneous third-order nonlinearity. At low volume fractions, the delayed hot-electron contribution to third-order nonlinearity increases linearly with the volume fraction.

High-order optical nonlinearities in plasmonic nanocomposites—a review

“…Many publications related to the basic characteristics of metal nanocolloids and solidstate metal composites appeared in the past years [65][66][67][68][69][70][71][72][73][74][75][76][77][78]. In the majority of the experiments the authors focused on the third-order properties of the materials.…”

“…When applied to the study of MDNCs, the nonlinearity management can be done by varying f and the incident laser intensity [98,105]. Indeed, due to large nonlinearity of metallic NPs, small changes in the filling fraction may produce significant modifications of the effective NL response of the nanocomposite [72,101,106,107].…”

Photoluminescence and nonlinear optical phenomena in plasmonic random media—A review of recent works

“…The optical response of silver colloids was studied under different experimental conditions and NL susceptibilities associated to high-order processes were measured [6][7][8]. The results support the description of the medium through effective NL susceptibilities of (2Nþ1) order, χ ð2N þ 1Þ ef f , with N¼1, 2, 3…, that include contributions from the NPs and the host liquid.…”

“…For instance, large NL susceptibilities of colloids based on silver and gold NPs, excited by lasers operating in the 400-1000 nm range, were demonstrated for different values of f [2,[4][5][6][7][8]. On the other hand many studies were focused on rareearth ions (REI) doped glasses containing metallic NPs [1,3,[9][10][11][12][13].…”

A large enhancement of (hyper)polarizabilities of polyyne capped by Cu

“…Both Cu and Ag have appealing linear and nonlinear optical properties when they individually exist as nanoparticles or nanoplanets [24][25][26][27]. In this work, we calculated the linear and nonlinear polarizabilities of the linear CuC 2n Cu and CuC 2n H (n = 1-7) molecules by using the ab initio finite field method.…”