通道间隔可切换的双Lyot滤波器的结构设计与性能分析  

Structural Design and Performance Analysis of Dual Lyot Filter with Switchable Channel Interval

作　　者：忻伶怡 周雪芳[1] 毕美华[1] 杨国伟[1] 胡淼[1] 李浩珍 王天枢[2] Xin Lingyi;Zhou Xuefang;Bi Meihua;Yang Guowei;Hu Miao;Li Haozhen;Wang Tianshu(School of Communication Engineering,Hangzhou Dianzi University,Hangzhou 310018,Zhejiang,China;Institute of Space Optoelectronics Technology,Changchun University of Science and Technology,Changchun 130022,Jilin,China)

机构地区：[1]杭州电子科技大学通信工程学院,浙江杭州310018 [2]长春理工大学空间光电技术研究所,吉林长春130022

出　　处：《中国激光》2022年第21期155-163,共9页Chinese Journal of Lasers

基　　金：浙江省教育厅一般科研项目(Y202146926);国家自然科学基金(61705055);浙江省重点研发计划项目(2019C01G1121168);浙江省大学生科技创新活动计划暨新苗人才计划项目(2022R407B065)。

摘　　要：在传输矩阵理论推导与实验验证的基础上,提出了一种通道间隔可切换的全光纤梳状滤波器。该滤波器基于双Sagnac环滤波结构,是两个Lyot滤波器的并联。滤波器的两条支路分别由偏振控制器(PC)和不同长度的保偏光纤(PMF)组成,可通过调节PCs,控制光进入PMF时的偏振态,实现通道间隔切换和消光比调谐。其中,通道间隔分别由两支路上的PMFs特性决定,通过改变PMFs的长度和双折射率,可得到不同的通道间隔可切换组合。在上述设计的基础上,增设了一个PC,经实验检验,滤波器的可调性得到了进一步提升。最后,实验证实了以此滤波器为基础构建的多波长光纤激光器(MWFL)在实现通道间隔切换方面的可行性。Objective Fiber comb filters are widely concerned because of simple structure, low cost, strong stability, and strong compatibility with optical fiber communication systems. A common application scenario for fiber comb filters involves multiwavelength fiber lasers( MWFLs). Generally, an all-fiber comb filter is fixed with a constant channel interval that is challenging to meet the needs of tunability in some practical uses. In previous research, our team has conducted detailed theoretical studies and transmission characteristics tests on a double Sagnac loop and experimentally verified its viability in channel interval switching when used in MWFL. In this research, we unravel the double Sagnac loop and transform it into a novel dual Lyot filter based on parallel polarization-maintaining fibers. The findings of theoretical analysis and experimental tests demonstrate that the channel interval is switchable and the extinction ratio is tunable with the polarization controller’s adjustment. The MWFL based on the dual Lyot filter is capable of generating a multiwavelength output with two various channel intervals. This research may provide some references for scholars who engage in the study of MWFL with high flexibility.Methods First, the designed dual Lyot filter’s transmission function is derived based on the theoretical analysis and the transfer matrix theory. Then, the transmission spectrum is simulated using the Matlab software. The channel interval switch function is confirmed from a theoretical perspective. By replacing the polarization-maintaining fibers(PMFs), various wavelength interval combinations can be accessible, further confirming the filtering structure’s flexibility in obtaining channel interval switching. After that, the impact of the polarization controller(PC) before PMF on the extinction ratio( ER) of the transmission spectrum is discussed. Furthermore, a PC is added to the proposed filter to optimize the filter’s ER performance and tunability. Moreover, to confirm the theoretical conclus

关 键 词：光纤光学 梳状滤波器 传输矩阵 Lyot滤波器 通道间隔可切换 

分 类 号：O436[机械工程—光学工程]