The Main Object Of The Second-order Nonlinear Optical Properties Of Doped Poled Polymer Film

Because of its excellent second-order nonlinear properties, Optical nonlinear organic materials especially azo class nonlinear optical materials have been extensity studied In optoelectronics, optical communication researches. In this paper, The PMMA doped azo compound films were prepared by using spin coating method. Their thickness, index of refractive and UV-Vis spectra were measured. The films were poled by corona poling method. The main works were as follows:1. The PMMA doped three different azo compound films were prepared by using spin coating method. Second harmonic generation (SHG) density were detected by real-time corona poling method. For azobenzene molecule with different substituent, the stronger the ability of push (pull) electron is, the bigger the value of SHG is. For the three systems the effective frequency-doubling coefficient is different. The result was disused: because of the ability of push (pull) electron is different; the first-order hyperpolarizability is different which determine the molecule will be poled easily or not.2. Nonlinear optical properties of IDMA/PMMA films were studied in different density, experimental result shows that the SHG raise at first then decline as the density of Azo-Dye molecules rise. Analyzed we know that at lower density the SHG raise because Azo-Dye molecules manifold, when the density is larger enough, intermolecular repulsion and intermolecular attraction which made the second order Polariabilityβsmaller can't be ignored, and SHG decline.3. Decay property of poled IDMA/PMMA film was detected at different temperatures, and Decay curve were fitted by Origin software. Results show that the average relaxation time becomes shorter with temperature increase; Decay property of poled IDMA/PMMA film was also detected at different thickness, Results show that the average relaxation time becomes longer with thickness increase.4. The effection of Molecular deflection angle at different thickness films and different temperature were studied. Result shows that the average alignment factor becomes bigger with temperature increase and For the films with different thickness, with the thickness increase the average alignment factor decrease.