Spectral And Nonlinear Optical Properties Of Organic Dye Tartrazine

Nonlinear optical(NLO)materials will be the key materials of the information age towards the future.The NLO materials are necessitated in the optoelectronic industry,such as optical switch,optical communication,optical information processing,optical computer,laser technology and etc.Recently,various NLO materials in recent decades has attracted widespread attention,including semiconductor quantum dots,inorganic nanofilms,metal nanoparticles,proton transfer materials and organic molecular materials.Based on the NLO molecule-designed theory,there are conjugated?bond structures in the organic dye molecule,which often leads to strong NLO effects.Thus,we choose the organic dye tartrazine as the research object.We perform the spectral and NLO investigation of the organic dye tartrazine.The content is as follows:Firstly,the absorption and fluorescence characteristics of organic dye tartrazine were studied by UV-vis spectrophotometer and fluorescence spectrophotometer.Two absorption bands were found,with absorption peaks of 257nm and 425nm respectively.Its absorption mainly comes from transition.The absorption peak,the best excitation wavelength and the variation of the absorption peak with the excitation wavelength are systematically analyzed.Secondly,the time-resolved fluorescence spectra of organic dye tartrazine at excitation wavelength of 369nm were measured by transient spectroscopy,and the fluorescence lifetime at peak wavelength of 551nm was calculated by fitting,and the mechanism of fluorescence generation was analyzed,which provided an effective basis for future correlation spectrum analysis.Finally,the nonlinear optical properties of organic dye-tartrazine were studied by Z-scanning technique using 532nm laser as excitation light and changing the excitation light energy.The results show that the organic dye lemon yellow has a large nonlinear optical coefficient under excitation of 532nm light.According to the results of ultraviolet absorption spectrum,the nonlinear absorption of organic dye tartrazine is attributed to two-photon absorption.The experimental results show that the nonlinear refractive index of tartrazine reaches the order of 10^-11esu and the nonlinear absorption cross section reaches a few hundred of GM,which indicate that tartrazine possess good nonlinear optical properties,which originate from the electron cloud distortion and the excited electron distribution.The excellent NLO properties of lemon yellow allow them to be potentially applied in light limiter,light switch,biological imaging,fluorescent labeling,full light switch and biological field.