Unveiling and engineering of third order optical nonlinearities in NiCo${}_2$O${}_4$ nanoflowers

Abstract

In this paper, we demonstrate NiCo${}_2$O${}_4$ (NCO) as an efficient new nonlinear optical material with straightforward potential applications in optical limiting devices. We obtain nonlinear absorption coefficient ($\beta$) and nonlinear refractive index ($n_2$) in parallel by performing Z-scan technique, in both open and closed aperture configurations, respectively. To understand the mechanism responsible for third order optical nonlinearity in NCO, we excited the sample with contrasting laser pulse durations, 7 ns and 120 fs, at two different off-resonant wavelengths. For ns excitation, nonlinearity is mediated by excited state absorption (ESA) and free-carrier absorption, that gives rise to large \b{eta}ESA and positive $n_2$. On the other hand, when excited with fs laser, two-photon absorption (TPA) takes place and bound carriers induce strong negative $n_2$. The values obtained for $\beta$ and $n_2$ in NCO are found to be higher among the family of well-known conventional transition metal oxides, therefore are promising for optics and other photonics applications.

6 figures, 4 tables, 24 pages

References in corpus (7)

• Optical Limiting and Theoretical Modelling of Layered Transition Metal Dichalcogenide Nanosheets
• Designing hybrid graphene oxide- gold nanoparticles for nonlinear optical response: Experiment and theory
• Enhancement of Two photon absorption with Ni doping in the dilute magnetic Semiconductor ZnO Crystalline Nanorods
• Quantification of nonlinear absorption in ternary As-Sb-Se chalcogenide glasses
• Role of thermal and photo annealing on nonlinear optical response of Ge30Se55Bi15 thin films
• Near resonant nanosecond laser driven nonlinear optical response in As50S50 thin films
• Pulse-duration dependence of saturable and reverse saturable absorption in ZnCo2O4 microflowers