The Nonlinear Optical Properties Of Phthalocyanine Dye At The Wavelength Of Red Light

Materials that possess nonlinear optical (NLO) properties have investigated extensively for their potential applications in optical switches,optical limiting devices, and received much attention. Therefore,it is important to look for the new nonlinear optical materials. In recent years,the cluster Polymer of metal with strong nonlinear optical properties have been studied popularly. Phthalocyanine dye as a promising optical nonlinear organic material has been widely studied. In order to enhance the nonlinear properties, we can change the center metal atom and design the molecular structure of the phthalocyanine.This paper introduces the theory of 4f coherent imaging technique. We improve the system into a double 4f system because the spatial distribution of the beam is unstable. We used the plush of the nonlinear parametric generator (OPG) to measure the third-order nonlinear optical properties of PbPc (CP)4 at the wavelength of 600nm. With the data simulation, we can get the nonlinear absorption coefficient is 6.8×10 ?12m/Wand the nonlinear refraction coefficient is 6.1×10 -19 m 2/W.When the time-resolved pump-probe technique is introduced into the 4f system, it can be used to measurement the dynamic characteristics of excited states nonlinear absorption and refraction. In the paper, we experimentally studied the dynamic excited-state nonlinearities of PbPc (CP)4 by 19ps laser plush at the wavelength of 532nm by the time-resolved pump-probe system based on 4f system. During the experiment, we use the CCD to get the nonlinear images with different time delay. Some photophysical parameters of the PbPc (CP)4 are obtained theoretically fitting the experimental curves using the excited-state nonlinearity theory and molecular three-energy-level model. The absorption cross sections of the ground stateσ0 = 1.2×10 ?21 m2 which is get from the linear transmittance and the absorption cross sections of first singlet stateσ1 = 5.2×10 ?21 m2, the molecular refractive index difference between the first excited singlet state and ground stateΔη=η1 ?η0 = 6.1×10 ?28 m3. According to its absorption spectrum, the nonlinear properties of PbPc (CP)4 at 600nm origins from the excited state refraction.