V-型化合物的非线性光学效应研究

论文总字数：32382字

摘 要

本文对非线性光学理论进行了简单概述，并简要介绍了查尔酮及其衍生物的结构与应用，总结了查尔酮衍生物目前在非线性光学领域的研究进展。较为详细地介绍了双/多光子吸收和非线性折射的相关理论，并介绍了Z-扫描表征技术的原理和通过Z-扫描曲线判断样品非线性吸收系数与非线性折射率符号的方法。

本文主要工作是合成了三种V-系列查尔酮衍生物［(1E,4E)-1-(4-甲氧基)-5-苯基-1,4-戊二烯-3-酮（V1）、(1E,4E)-1-(4-甲硫基)-5-苯基-1,4-戊二烯-3-酮（V2）和(1E,4E)-1-(4-二甲氨基)-5-苯基-1,4-戊二烯-3-酮（V3）］，分析了其取代基与非线性光学效应的结构-性质关系。采用密度泛函理论结合半经验方法，数值计算了三种衍生物在800 nm波长下的二阶超分子极化率。在800 nm波长下对三种衍生物进行了飞秒脉冲激光Z-扫描实验，并计算得到了三种衍生物的非线性吸收系数和非线性折射率。结果发现三种衍生物的非线性光学效应强度呈现V3gt;V2gt;V1的顺序。原因在于V3中的取代基作为电子供体具有比另外两种衍生物中的取代基更强的电子供给能力，从而增强了分子的非线性光学性质。因此通过合适的取代基的选择，就能设计出具有强非线性光学效应的D-π-A-π-A型查尔酮分子。

关键词：非线性光学效应，查尔酮衍生物，Z-扫描表征技术，结构-性质关系

Abstract

This paper briefly introduces the theory of nonlinear optics, and briefly introduces the structure and application of chalcone and its derivatives, and summarizes the research progress of chalcone derivatives in the field of nonlinear optics in recent years. The related theories of two/multi-photon absorption and nonlinear refraction are introduced in detail, and the principle of Z-scan technique and the method of extracting nonlinear absorption and nonlinear refraction of samples by the Z-scan curve are introduced.

The main content of this paper is to synthesize three V-series chalcone derivatives, i.e., (1E,4E)-1-(4-methoxyphenyl)-5-phenylpenta-1,4-dien-3-one (V1), (1E,4E)-1-[4-(methylsulfanyl)phenyl]-5-phenylpenta-1,4-dien-3-one (V2), and (1E,4E)-1-[4-(dimethylamino)phenyl]-5-phenylpenta-1,4-dien-3-one (V3). The structure-property relationship between their substituents and nonlinear optical effects is analyzed. Theoretically, the second hyperpolarizability of three derivatives at the wavelength of 800 nm is numerically computed from the combination of density functional theory and semi-empirical method. The femtosecond-pulsed laser Z-scan measurements were performed on the three derivatives at 800 nm. The nonlinear absorption coefficients and nonlinear refractive indexes of the three derivatives were evaluated. The results show that the magnitude of nonlinear optical response of three derivatives is in the order of V3gt;V2gt;V1. The reason is that the substituent -N(CH₃)₂ in V3 as an electron donor has a stronger electron donating ability than that of substituents in the other two derivatives, thereby enhancing the nonlinear optical properties of the molecule. Therefore, D-π-A-π-A chalcone molecules with strong nonlinear optical effects can be designed by the selection of suitable substituents.

Key words: Nonlinear optical effect; chalcone derivatives; Z-scan technique; structure-property relationship.

目 录

1. 绪论……………………………………………………………………………………1

1.1 引言…………………………………………………………………………………1

1.2 非线性光学概述……………………………………………………………………2

1.3 查尔酮衍生物及其研究现状简介…………………………………………………3

1.4 本文的主要研究内容………………………………………………………………5

1. 非线性光学效应和Z-扫描表征技术 ………………………………………………6

2.1 非线性光学原理……………………………………………………………………6

2.1.1 非线性吸收………………………………………………………………6

2.1.2 非线性折射………………………………………………………………8

2.2 Z-扫描表征技术……………………………………………………………………9

2.3 本章小结……………………………………………………………………………11

1. V-型化合物的非线性光学性质研究…………………………………………………12

3.1 引言…………………………………………………………………………………12

3.2 实验设计……………………………………………………………………………12

3.2.1 半经验计算………………………………………………………………12

3.2.2 非线性光学基团设计……………………………………………………13

3.3 实验部分……………………………………………………………………………14

3.3.1 材料合成…………………………………………………………………14

3.3.2 Z-扫描表征………………………………………………………………15

3.4 结果与讨论…………………………………………………………………………15

3.4.1 DFT结合半经验方法……………………………………………………15

3.4.2 材料特性…………………………………………………………………18

3.4.3 三阶非线性光学特性……………………………………………………19

3.5 本章小结……………………………………………………………………………22

1. 总结与展望……………………………………………………………………………24

致谢 ……………………………………………………………………………………………26

参考文献 ………………………………………………………………………………………27

第一章 绪论

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