一种近红外光记录与存储材料——克酮酸染料的三阶非线性光学性质

克酮酸染料是一类新型的近红外吸收染料,由于具有良好的光热稳定性和荧光性能,因而在光记录与存储等领域有着潜在的应用价值.本文利用简并四波混频技术,在近红外区不同吸收波长,在脉宽为130 fs条件下研究了一种吲哚克酮酸染料在溶液和薄膜中的三阶非线性光学性质.该克酮酸染料在773 nm,四氢呋喃溶液中的共振三阶超分子极化率γ为5.3×10-29esu,在薄膜中的共振三阶非线性极化率χ(3)值达到10-8esu数量级.同时,对于三阶非线性光学响应及其动力学机制也进行了研究和探讨.     

Synthesis and characterization of side‐chain polyimides for second‐order nonlinear optics via a post‐azo‐coupling reaction

A two‐step, generally applicable synthetic approach for nonlinear optical (NLO) side‐chain polyimides was developed. This included the preparation of a preimidized, organosoluble polyimide with benzene moiety pendant from main chains, followed by the covalent bonding of the NLO chromophores onto the polyimide backbone via a post‐azo‐coupling reaction. The degree of functionalization of polyimides was estimated by UV‐VIS spectroscopy. The glass transition temperature (T_g) of a polyimide decreased by only 10–20°C after the functionalization, which was much smaller than the decrease in T_g when the chromophores were chemically bonded to the polyimide main chains through an ether linkage using a post‐Mitsunobu condensation. The solubility and thermal stability of polyimides were also studied. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 290–295, 2000