基于掺铒光纤动态光栅与光纤Bragg光栅F-P腔特性的研究

发布时间：2018-01-20 01:57

本文关键词： 动态光栅光纤Bragg光栅 F-P腔传输矩阵反射谱　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：人们对于光纤Bragg光栅和动态光纤光栅的研究已经非常成熟。光纤Bragg光栅的体积小,质量轻,柔韧度高,耐高温、抗电磁干扰以及化学性能稳定都很强,因此在应用中有很大的优势。另一方面,由于动态光栅在光纤传感器、自适应干涉仪以及光学存储元件等方面有重要应用,因此在掺铒光纤中写入的动态光栅引起了人们的关注。动态光栅有一些特有的优点,例如光栅的中心波长、光栅强度以及线宽等参量动态可调。本论文利用光纤Bragg光栅和动态光纤光栅的固有优势,设计基于掺铒光纤动态光栅与光纤Bragg光栅的F-P腔,并研究了它的特性。首先研究了在掺铒光纤中形成的动态光栅,对其透射率和反射率进行计算。接下来研究其与光纤Bragg光栅形成的F-P腔的特性。这种F-P腔的一个重要性质是可以动态调制腔的透射和反射特性。相比于两个光纤Bragg光栅制成的F-P腔,可调的系统相比于固定的系统更加灵活。而两个光纤Bragg光栅制成的F-P腔,由于腔长固定,F-P腔的共振响应不能动态可调。我们提出的一个可调的动态光栅和光纤Bragg光栅形成的F-P腔,它的透过和反射特性可以通过调节相干场的拉比频率等参数进行动态调制。另外,在F-P腔两端,两个紫外写入的光栅由于制作流程的限制,通常两个光栅很难完全对称,如不对称的光栅周期、折射率调制深度等。这种不对称性会降低F-P腔的优势特性。用动态光栅和光纤Bragg光栅形成的F-P腔,只要通过改变波长、耦合场的拉比频率等,就可以克服这种不对称的缺陷。本论文的研究成果如下:1.针对具体的二能级掺铒光纤动态光栅模型,根据半经典相互作用理论以及耦合模理论,算出二能级掺铒光纤动态光栅的透过率和反射率。实验验证二能级掺铒光纤动态光栅的存在,并根据计算出的结果进行数值分析,画出在不同参数下的二能级掺铒光纤动态光栅反射谱。2.应用传输矩阵理论,算出掺铒光纤动态光栅与光纤Bragg光栅形成的F-P腔的透过率与反射率。对于动态F-P腔的三个部分分别进行参数的调制,并进行数值分析。改变的参数分别为:动态光纤中相干场的拉比频率,光纤Bragg光栅的折射率调制深度以及F-P腔的腔长,画出多种情况下的反射谱,分析以上参数改变对于动态F-P腔光学性质的影响。本论文对动态光栅与光纤Bragg光栅形成F-P腔的特性进行了研究,对于后续的实验与实际应用提供了一些参考。
[Abstract]:The research of fiber Bragg grating and dynamic fiber grating is very mature. Fiber Bragg grating is small in volume, light in weight, high in flexibility and high temperature resistance. The anti-electromagnetic interference and chemical stability are very strong, so it has a great advantage in application. On the other hand, because of the dynamic grating in the fiber sensor. Since adaptive interferometers and optical memory devices have important applications, the dynamic grating written in erbium-doped fiber has attracted much attention. Dynamic grating has some special advantages, such as the center wavelength of grating. The intensity and linewidth of the grating are dynamically adjustable. In this paper, the inherent advantages of the fiber Bragg grating and the dynamic fiber grating are utilized. The F-P cavity based on erbium-doped fiber dynamic grating and fiber Bragg grating is designed, and its characteristics are studied. Firstly, the dynamic grating formed in erbium-doped fiber is studied. The transmissivity and reflectivity of F-P cavity formed with fiber Bragg grating are studied. One of the important properties of F-P cavity is the transmission and reflection characteristics of dynamically modulated resonator. Compared with the F-P cavity fabricated by two fiber Bragg gratings. The adjustable system is more flexible than the fixed system, and the F-P cavity made by two fiber Bragg gratings is fixed because of the length of the cavity. The resonant response of F-P cavity can not be dynamically adjustable. We propose a tunable dynamic grating and fiber Bragg grating to form F-P cavity. Its transmission and reflection characteristics can be dynamically modulated by adjusting the Rabi frequency of coherent field. In addition, at the two ends of F-P cavity, two ultraviolet writing gratings are limited by the fabrication process. Usually two gratings are difficult to be completely symmetric, such as asymmetric grating periods. The refractive index modulation depth and so on. This asymmetry will reduce the predominance of F-P cavity. The F-P cavity formed by dynamic grating and fiber Bragg grating can only change the wavelength, the Rabi frequency of coupling field, and so on. The research results of this thesis are as follows: 1. For the specific two-level erbium-doped fiber dynamic grating model, according to the semi-classical interaction theory and coupling mode theory. The transmittance and reflectivity of the two-level erbium-doped fiber dynamic grating are calculated. The existence of the two-level erbium-doped fiber dynamic grating is verified by experiments, and the numerical analysis is carried out according to the calculated results. The reflection spectra of two-level erbium-doped fiber gratings with different parameters are drawn. 2. The transfer matrix theory is applied. The transmittance and reflectivity of the F-P cavity formed by the erbium-doped fiber dynamic grating and the fiber Bragg grating are calculated. The three parts of the dynamic F-P cavity are modulated by the parameters. Numerical analysis shows that the parameters changed are: the Rabi frequency of coherent field in dynamic fiber, the refractive index modulation depth of fiber Bragg grating and the cavity length of F-P cavity. The influence of the above parameters on the optical properties of the dynamic F-P cavity is analyzed. In this paper, the characteristics of the F-P cavity formed by the dynamic grating and the fiber Bragg grating are studied. Some references are provided for further experiments and practical applications.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN253

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