Effect of betanin natural dye extracted from red beet root on the non linear optical properties ZnO nanoplates embedded in polymeric matrices

Abstract

In this article, we have investigated the effect of betanin natural dye extracted from red beetroot on nonlinear optical properties of ZnO nanoplates embedded in polymeric matrices through the Z-scan technique using an Nd: YAG laser (532 nm, 7 ns, 10 Hz). We observed reverse saturable absorption (RSA) at 532 nm for dye and ZnO nanoplates. A strong influence on RSA behavior of nanoplates-PVA matrix was observed by adding betanin natural dye. The influence of betanin on the nonlinear character of ZnO-PVA system leads to saturable absorption and again to RSA on increasing input fluence. Such a change over in the sign of the nonlinearity is due to the interplay of the exciton bleaching and optical limiting mechanisms, and probably due the presence of sucrose. Theoretical analysis has been performed using a model based on nonlinear absorption coefficient and saturation intensity. The result of present study gives an additional mechanism for the gain enhancement in dye doped ZnO matrix.

Influence of Pr Doping on the Structural, Morphological, Optical, Luminescent and Non-linear Optical Properties of RF-Sputtered ZnO Films

“…Earlier reports show that ZnO exhibits second and third-order nonlinear optical behavior, both in single crystals and in thin films [90]. The 1 wt% Pr doped ZnO film shows a normalized transmittance peak at the beam focus, indicating a negative nonlinear absorption due to saturable absorption (SA) [94,95].However, the 5 wt% Pr doped ZnO film exhibits astrong positive nonlinear absorption due to reverse saturable absorption(RSA) [89].…”

“…With increasing intensity, if the excited states show saturation owing to their long lifetimes, the transmission will show saturable absorption behavior. If the excited state has strong absorption compared with that of the ground state, the transmission will show reverse saturable absorption behavior [30,89]. Earlier reports show that ZnO exhibits second and third-order nonlinear optical behavior, both in single crystals and in thin films [90].…”

“…These defect centers can act as photon-trapping states over the surface. In semiconductor nanocrystals, the surface chemistry of the localized trapping states is responsible for the optical nonlinear properties [89].If the linear absorption cross-section of the trap states is higher than the ground state, then direct excitation from these surface-trapped states will promote the photocarriers to higher energy levels in the nanocrystal, giving rise to the optical nonlinearity. The nonlinear optical response of trapped states also depends on the density and lifetime of trapped states [89,97,98].…”

Size Dependent Optical Nonlinearity and Optical Limiting Properties of Water Soluble CdSe Quantum Dots

“…The nonlinear optical characterization of the samples was carried out using the -scan technique at 532 nm [13,14]. The samples to be investigated were translated through the focal point of a lens of focal length of 20 cm.…”

Z-scan and optical limiting properties of Hibiscus Sabdariffa dye

“…Similarly to the so-called poled organic materials, which are asymmetric organic molecules with a large molecular hyperpolarizability due to their electron delocalization along the conjugated backbone [1,2], specific natural dyes have been found to exhibit very attractive nonlinear optical (NLO) characteristics with nonlinear coefficients 10 4 -10 6 times higher than that of CS 2 . This natural dye family includes Chlorophyll, red Carmine, Chinese tea and betanin, Hibiscus Sabdariffa as well as, recently, functionalized DNA [2][3][4][5][6].…”