N型四能级原子系统中的克尔非线性特性研究
发布时间：2019-06-12 07:59
【摘要】：自从上世纪60年代第一台激光器被发明以来,人们可以将强度很高、单色性很好的激光光束与物质相互作用,从而观察到一系列前所未有的新奇现象,如光学整流、差频、和频、倍频、混频、受激拉曼散射、光束自聚焦等等,为了深入了解这些有趣的现象,非线性光学理论便应运而生了。 随着非线性光学的研究日趋成熟,人们开始逐渐将已取得的研究成果广泛应用到各个科技领域中,如利用光学非线性效应在光纤中产生光孤子、通过交叉相位和自相位调制制作全光开光、制造读取速度更快,保真度更高的光存储器件等等,这些应用在未来的量子计算与量子通信领域将产生巨大作用。基于非线性光学丰富并且重要的应用价值,越来越多的人们开始关注如何增强与调控激光与介质相互作用时的光学非线性效应。近年来人们逐渐将非线性光学的研究拓展至量子水平,比如在单光子条件和微腔中探究非线性增强的量子相干效应等等。 我们采用密度矩阵方法对N型四能级系统与三个光场的相互作用过程进行了数值模拟,计算中考虑了多普勒效应、碰撞增宽等多种实际效应的影响；并用缀饰态理论进行了分析和解释。实验上,自行搭建了光学腔系统,通过腔透射谱的不对称度获得了N型四能级系统的自克尔非线性系数,并估算得到了该系数的绝对值。同时,测量了不同调节场强度下自克尔非线性系数随探测场频率的变化,所得结果和理论计算基本吻合。对两者之间存在差异的原因我们也进行了较为合理的分析。本研究将为光孤子传输及基于自相位调制的部分应用提供新思路,从而更好地应用在光纤通信、全光开关等。
[Abstract]:Since the invention of the first laser in 1960s, people can interact with matter with high intensity and good monochromaticity, and a series of unprecedented novel phenomena, such as optical rectification, difference frequency, sum frequency, frequency doubling, mixing, stimulated Raman scattering, beam self-focusing and so on, have been observed. In order to deeply understand these interesting phenomena, nonlinear optical theory emerges as the times require. With the maturity of nonlinear optics, people begin to widely apply the existing research results to various scientific and technological fields, such as the generation of optical solitons in optical fiber by optical nonlinear effect, the fabrication of all-optical open light by cross-phase and self-phase modulation, the fabrication of optical memory devices with faster reading speed and higher fidelity, and so on. These applications will play a great role in the field of quantum computing and quantum communication in the future. Based on the rich and important application value of nonlinear optics, more and more people begin to pay attention to how to enhance and regulate the optical nonlinear effect of laser-dielectric interaction. In recent years, the study of nonlinear optics has been gradually extended to the quantum level, such as exploring the quantum coherence effect of nonlinear enhancement in single-photonic conditions and microcavities. In this paper, the interaction process between N-type four-level system and three light fields is simulated by density matrix method, and the effects of Doppler effect, collision broadening and other practical effects are taken into account in the calculation, and the affixed state theory is used to analyze and explain the interaction between N-type four-level system and three light fields. In the experiment, the optical cavity system is built, and the self-Kerr nonlinear coefficient of the N-type four-level system is obtained by the asymmetry of the cavity transmission spectrum, and the absolute value of the coefficient is estimated. At the same time, the variation of self-Kerr nonlinear coefficient with the frequency of detection field under different intensity of regulating field is measured, and the results are in good agreement with the theoretical calculation. We also make a reasonable analysis of the reasons for the differences between the two. This study will provide a new idea for optical soliton transmission and some applications based on self-phase modulation, so as to be better used in optical fiber communication, all-optical switch and so on.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN248
本文编号：2497858
[Abstract]:Since the invention of the first laser in 1960s, people can interact with matter with high intensity and good monochromaticity, and a series of unprecedented novel phenomena, such as optical rectification, difference frequency, sum frequency, frequency doubling, mixing, stimulated Raman scattering, beam self-focusing and so on, have been observed. In order to deeply understand these interesting phenomena, nonlinear optical theory emerges as the times require. With the maturity of nonlinear optics, people begin to widely apply the existing research results to various scientific and technological fields, such as the generation of optical solitons in optical fiber by optical nonlinear effect, the fabrication of all-optical open light by cross-phase and self-phase modulation, the fabrication of optical memory devices with faster reading speed and higher fidelity, and so on. These applications will play a great role in the field of quantum computing and quantum communication in the future. Based on the rich and important application value of nonlinear optics, more and more people begin to pay attention to how to enhance and regulate the optical nonlinear effect of laser-dielectric interaction. In recent years, the study of nonlinear optics has been gradually extended to the quantum level, such as exploring the quantum coherence effect of nonlinear enhancement in single-photonic conditions and microcavities. In this paper, the interaction process between N-type four-level system and three light fields is simulated by density matrix method, and the effects of Doppler effect, collision broadening and other practical effects are taken into account in the calculation, and the affixed state theory is used to analyze and explain the interaction between N-type four-level system and three light fields. In the experiment, the optical cavity system is built, and the self-Kerr nonlinear coefficient of the N-type four-level system is obtained by the asymmetry of the cavity transmission spectrum, and the absolute value of the coefficient is estimated. At the same time, the variation of self-Kerr nonlinear coefficient with the frequency of detection field under different intensity of regulating field is measured, and the results are in good agreement with the theoretical calculation. We also make a reasonable analysis of the reasons for the differences between the two. This study will provide a new idea for optical soliton transmission and some applications based on self-phase modulation, so as to be better used in optical fiber communication, all-optical switch and so on.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN248
【参考文献】
相关博士学位论文 前1条
1 李淑静;多能级原子系统中量子相干增强的弱光非线性[D];山西大学;2008年
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