Investigation On The Optical Nonlinearities Of Bis (Phthalocyninato) Rare Earth Double-decker Complexes

With the development of nonlinear optical effects and its applications,finding materials with strong nonlinear effect and fast response has been a necessary research trend.In the past few years,it has been demonstrated that the novel functional materials are applied to military,technology,medical and other fields.Many researchers pay close attention to organic materials because of its unique photonic,electronic and magnetic properties.Particularly,due to phthalocyanine has large delocalized ?-electron system,high thermal chemical stability and the diversity of molecular structure,it has been a very important functional material.Therefore,it is very crucial to characterize the nonlinear photonic properties of phthalocyanine complexes and evaluate their practical application values.The innovation of this thesis mainly includes two parts.First,we investigated the nonlinear optical properties of symmetrical sandwich-type bis(phthalocyaninato)rare earth complexes and its oxidation product,its reduced product.The results indicate that the nonlinear optical properties of bis(phthalocyaninato)rare earth complexes could be manipulated by the redox reaction.Secondly,the nonlinear absorption effect of a series of asymmetric sandwich-type bis(phthalocyaninato)rare earth complexes was investigated.It is found that found complexes with large delocalized ?-electron can effectively enhance its two-photon absorption cross section.The main research works are as follows:1.We briefly introduced the basic characteristics of phthalocyanine complexes and their current development situation in nonlinear optics.We described the basic theories and experimental method of third-order nonlinear optical effects using Z-scan technique in detail.We used the standard samples CdS and quartz to illustrate how to measure the third-order optical nonlinearity of materials by Z-scan technique.2.We performed the experimental study on the third-order nonlinear optical properties and the relationship between the input irradiance and nonlinear transmittance of the homoleptic bis(phthalocyaninato)rare earth praseodymium double-decker complexs.By performing the closed-and open-aperture Z-scan measurements at the wavelenghth of 800 nm,we investigated the third-order nonlinear refraction effect and nonlinear absorption effect of the neutral complex Pr(OOPc)2 and its oxidation species[Pr(OOPc)2]+ and reduced species[Pr(OOPc)2]-,respectively.According to the experiment results combined spectra properties,we analyzed the underlying mechanisms of the observed optical nonlinearities.More importantly,it is found that the redox reaction changes the nonlinear optical properties of bis(phthalocyaninato)rare earth complexes.Finally,we discussed their applications in optical limiter,all-optical switch and saturable absorber.3.We prepared a series of asymmetric sandwich-type bis(phthalocyaninato)rare earth complexes Yb(Pc)(OOPc),Y(Pc)(OOPc),Er(Pc)(OOPc),Ho(Pc)(OOPc)and investigated their nonlinear absorption effects by femtosecond Z-scan experiments.Due to the highly delocalized ?-electron system and intense ?-? interactions between the phthalocyaninato macrocycles,all complexes exhibited large two-photon absorption.It is found that all these complexes had excellent optical limiting behaviors.