基于相移可调谐啁啾光纤光栅多波长滤波器的研究

发布时间：2018-05-05 06:27

本文选题：Ⅴ-Ⅰ传输矩阵法 + 啁啾相移光纤光栅　；参考：《北京交通大学》2015年硕士论文

【摘要】：相移光纤光栅是通过在常规布拉格光纤光栅(FBG)的某些特定位置引入相移而形成,相比普通FBG,相移光栅可以在反射谱的阻带中打开一个或多个线宽极窄的透射窗口,实现透射型滤波。而且,其透射窗口的位置可以通过改变相移量来调整,窗口的通透率以及线宽也可以根据通过调整相移点的位置来改变,因而可以根据不同的需要合理设计相移的数量、大小及位置,获得不同线宽和滚降特性的透射峰,并且相移光栅还具有插入损耗低、偏振无关等优点。因此其在窄带滤波、光纤激光器、波分解复用器、全光逻辑器件以及光纤传感等领域得到广泛应用,成为新型光器件的研究热点之一。啁啾相移光纤光栅是通过在啁啾光纤光栅中引入相移而形成,因此综合了啁啾光栅和相移光栅的一些重要特性,其反射带宽和透射窗口的线宽可以在很宽的范围内调谐,更加适用于多通道滤波。本文正是基于啁啾相移光纤光栅优良的滤波特性,通过在线性啁啾光栅中引入可调谐相移来实现波长和带宽均可调谐的多波长滤波器,从而在实际应用中实现更加灵活的波长选择。本文完成的主要工作和取得的成果如下： 1.基于规则光波导模式的正交性,详细推导了相移光纤光栅的耦合模方程,对相移光纤光栅的三种分析方法,传输矩阵法、多层膜法以及V-I传输矩阵法,进行了详细比较和误差分析,验证了V-I传输矩阵法能够满足分析的精度,并且大大提高了运算效率。 2.利用V-I传输矩阵法,对均匀相移光纤光栅和啁啾相移光纤光栅的透射谱特性进行比较分析,对比总结了两者在不同相移参数及光栅参数下的传输规律,为新型相移光纤光栅器件的研究提供依据。 3.实验研究了压电陶瓷(PZT)在线性啁啾光纤光栅中引入一个可调谐的且稳定的相移的基本特性,并分析总结了相移位置间隔及啁啾系数对啁啾相移光纤光栅陷波滤波器的波长间距的影响。结果表明,波长间距随相移位置间隔和啁啾系数的增长呈线性增长,且前者线性增长的灵敏度最大可达0.383nm/cm。在实际应用中可依据这两个线性关系来优化选择相移位置、相移数量及啁啾系数,并以PZT来控制相移量变化,设计出满足不同特性的多波长滤波器。
[Abstract]:Phase-shifted fiber gratings are introduced by introducing phase at specific locations of conventional fiber Bragg gratings (FBGs). The phase shifting grating can open one or more linewidths in the stopband of the reflection spectrum compared with the ordinary FBGs. Very narrow transmission window to achieve transmission-type filtering. Moreover, the position of its transmission window can be changed by changing the phase shift The window permeability and linewidth can also be adjusted by adjusting the position of the phase shift point, because The number, size and position of phase shift can be reasonably designed according to different needs, and different linewidth and roll down can be obtained. The phase-shifted grating also has the advantages of low insertion loss and polarization-independent. So it's narrow. The fields of band filter, fiber laser, wave decomposition multiplexer, all optical logic device and optical fiber sensor have been widely used. Universal application has become one of the research hotspots in new optical devices. Chirped phase-shifted fiber gratings are formed by introducing phase shift into chirped fiber gratings, so chirped fiber gratings are synthesized. Some of the important properties of the chirped grating and phase-shifted grating are reflected bandwidth and the linewidth of the transmission window can be very wide Range tuning is more suitable for multi-channel filtering. This paper is based on the excellent filter of chirped phase-shifted fiber grating. By introducing tunable phase shift into linearly chirped gratings to achieve tunable wavelengths and bandwidths Wavelength filter, thus realizing more flexible wavelength selection in practical applications. Main work accomplished in this paper And the results achieved are as follows: 1. Based on the orthogonality of regular optical waveguide modes, the coupled mode equations of phase-shifted fiber gratings are derived in detail. The three analytical methods of phase-shifted fiber gratings, the transfer matrix method, the multilayer membrane method and the V-I transmission matrix method, are presented. A detailed comparison and error analysis are carried out to verify that V-I transmission matrix method can meet the accuracy of the analysis and greatly improve the efficiency of calculation. 2. By means of V-I transmission matrix method, the transmission spectrum characteristics of homogeneous phase-shifted fiber grating and chirped phase-shifted fiber grating are compared and analyzed, and the transmission rules of the two gratings under different phase shift parameters and grating parameters are compared and summarized. It provides a basis for the study of novel phase-shifted fiber grating devices. 3. The basic characteristics of introducing a tunable and stable phase shift into a linearly chirped fiber grating by piezoelectric ceramics PZT are experimentally investigated. The influence of phase shift space and chirp coefficient on the wavelength spacing of chirped phase-shifted fiber grating notch filter is analyzed and summarized. The results show that the wavelength spacing increases linearly with the increase of phase shift spacing and chirp coefficient, and the sensitivity of the former increases linearly to 0.383 nm / cm ~ (-1). In practical application, the phase shift position, the number of phase shifts and the chirp coefficient can be optimized according to these two linear relations. The phase shift variation can be controlled by PZT, and a multi-wavelength filter with different characteristics can be designed.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN713

【参考文献】