Concentration and wavelength dependence of the effective third-order susceptibility and optical limiting of C₆₀in toluene solution

Abstract

The opticd limiting action of CSU in toluene solution is mainly due to revem saturable absorption (RSA). It is shown that the formalism describing nonlinear optical response due to instantaneous two-photon absorption can be used in the case of sequential two-photon absorption, yielding effective values of the relevant parameters of optical nonlinearity due to RSA. The effective twc-photon absorption parameter and the effective nonlinear refractive index parameter y&, which are related respectively to the imaginary and real parts of the effective third-order susceptibility $2. were measured by the L-scan technique as a function of fullerene concentration and of incident laser intensity and wavelength over the 42W nm region. The concentration dependence of these parameters indicates that the solution is optically lhin as far as the ground state of Cm is concerned, whereas he wavelength dependence confirms the applicability of the formalism used in the sequential two-photon absorption model. Comparisons are made with other I-scan results on Cm.

Nonlinear optical response of some Graphene oxide and Graphene fluoride derivatives

“…excitation with shorter laser pulse results in lower NLO response, since the response, in this case, arises from phenomena (e.g., electronic excitation, molecular re-orientation, Kerr effect, etc.) which are associated with smaller magnitude NLO response and are occurring in faster time scales as well, as it has been shown for example in the case of fullerenes [34,35]. Another consequence of this situation is that shorter laser pulses give rise to weaker NLO absorption, facilitating the measurement of the NLO refraction which otherwise can be concealed by the relatively stronger NLO absorption.…”

“…These NLO quantities are usually expressed in terms of the nonlinear absorption coefficient, β (m/W), and the nonlinear refractive index parameter, ′ (m 2 /W), which are related to the imaginary (Imχ (3) ) and real (Reχ (3) ) parts of the third-order nonlinear susceptibility, χ (3) , denoting in a more compact way the strength of the NLO response of a sample, through the following relations: The details of the Z-scan technique have been presented in details elsewhere [34,35], and only a brief description will be presented here. So, according to this technique the normalized transmittance of a sample translated along the propagation direction (e.g.…”

Optoelectronic and photoacoustic studies of an organic dye synthesized through green route

“…This is a favourable condition for reverse saturation absorption to occur. To confirm this, the value of β was evaluated with different on-axis peak intensities (I0) ranging from 1. suggests that excited state absorption be the principal mechanism for nonlinear absorption [9], which finds applications in optoelectronics.…”

Donor-Acceptor Conjugated Polymers and Their Nanocomposites for Photonic Applications

“…15,  is found to decrease with increasing input intensity. Such fall-off of  with increasing intensity is a consequence of the reverse saturable absorption (Couris et al, 1995). With increasing intensity the total absorption of these polymers approaches asymptotically the absorbance of the triplet state.…”