基于光循环移频环的可重构微波光子滤波器  

A Reconfigurable Microwave Photonic Filter Based on an Optical Recirculating Frequency Shifting Loop

作　　者：陈权 王光英[1,2] 易振钊 曹元 冯新焕 关柏鸥[1,2] CHEN Quan;WANG Guangying;YI Zhenzhao;CAO Yuan;FENG Xinhuan;GUAN Baiou(Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communication,Institute of Photonics Technology,Jinan University,Guangzhou 510632,China;College of Physics&Optoelectronic Engineering,Jinan University,Guangzhou 510632,China)

机构地区：[1]暨南大学光子技术研究院广东省光纤传感与通信重点实验室,广州510632 [2]暨南大学物理与光电工程学院,广州510632

出　　处：《光子学报》2024年第11期51-60,共10页Acta Photonica Sinica

基　　金：国家自然科学基金(No.62275107);广东省自然科学基金(No.2021A1515011944)。

摘　　要：基于光循环移频环的频域多载波特性和时间延迟特性构建了一种结构简单、高可重构性的微波光子滤波器。光循环移频环的等间隔时间延迟特性可用于在不同抽头之间引入时间延迟。另外,由于光循环移频环所产生的多个光载波之间的频率差较大,因而可以避免由于光载波的高相干性所导致的强度干扰,可实现稳定的频谱响应。利用可编程光滤波器对光循环移频环的输出光谱进行整形,可实现不同抽头的筛选和每个抽头权重的调节,从而获得微波光子滤波器抽头数和自由频谱范围的有效调谐。实验展示了自由频谱范围为3.85 MHz情况下抽头数在2、5、10之间的切换,以及抽头数为2的情况下,自由频谱范围在3.85 MHz、1.925 MHz以及770 kHz之间的切换。通过光谱整形技术,实现了微波光子滤波器抽头数和自由频谱范围的可重构。Microwave Photonic Filters(MPFs)can find applications in the fields of optical communications,radar,optical fiber sensing.Due to the implementing of high-frequency optical signals and different optical processing devices,MPFs can achieve low loss,large bandwidth and compatible communication.To construct a finite impulse response MPF,researchers have proposed a variety of tapping and delay structures.An MPF can be classified as coherent one or incoherent one,according to the coherent characteristic of the adopted optical carriers.A simple approach of Phase-Modulation to Intensity-Modulation(PM-IM)conversion is usually used to construct a coherent MPF,but the frequency response of the MPF is limited by the adopted optical filter.The principle of the incoherent MPFs is based on the impulse response filters,which are constructed through multiple taps and time delays.One of the important indicators to evaluate the performance of the MPFs is the reconfigurability.In terms of tap implementation,using physical paths with equally spaced time delay is a common method,but this requires complicated switching structures to tune the length of each optical path.Another common approach is to use multiwavelength sliced broadband optical sources or incoherent laser arrays,combined with dispersion fibers to achieve time delay.Usually,the positive coefficient MPFs require incoherent light sources to reduce interference between the adjacent taps,b ut it will increase the system noise.Therefore,how to achieve a high signal-to-noise ratio incoherent filter with tunable and reconfigurable performance is one of the critical issues that needs to be solved urgently in the field of microwave photonic signal processing.In this paper,an MPF with a simple structure and a high reconfigurability is demonstrated based on an optical Recirculating Frequency Shifting Loop(RFSL).By adding a Single-Sideband(SSB)modulator to an optical fiber loop,a new optical frequency component will be generated each time when the optical carrier passes through the S

关 键 词：微波光子滤波器 光循环移频环 光频梳 抽头数 自由频谱范围 

分 类 号：TN249[电子电信—物理电子学]