基于螺旋长周期光纤光栅的宽带模式转换器  

Broadband Mode Converter Based on Helical Long-Period Fiber Gratings

作　　者：张伟栋 马跃辉 姜晨 陈龙 刘云启 Zhang Weidong;Ma Yuehui;Jiang Chen;Chen Long;Liu Yunqi(Key Laboratory of Specialty Fiber Optics and Optical Access Network,School of Communication&Information Engineering,Shanghai University,Shanghai 200444,China;Advanced Photonic Technology Lab,College of Electronic and Optical Engineering&College of Flexible Electronics(Future Technology),Nanjing University of Posts and Telecommunications,Nanjing 210023,Jiangsu,China)

机构地区：[1]上海大学通信与信息工程学院特种光纤与光接入网重点实验室,上海200444 [2]南京邮电大学电子与光学工程学院、柔性电子(未来技术)学院先进光子技术实验室,江苏南京210023

出　　处：《激光与光电子学进展》2024年第15期96-102,共7页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(62075124)。

摘　　要：随着光通信网络的发展,高性能宽带模式转换器成为了迫切需求。提出并实验制备了强调制相移少模光纤螺旋长周期光栅,其可以实现全光纤宽带轨道角动量模式转换器的功能。通过增大二氧化碳激光的辐射功率在较短的少模光纤中制备强调制光栅可以显著增大光栅带宽,当在强调制光栅引入相移时,光栅的模式转换带宽会进一步增大。高阶模式转换的10-dB带宽均大于200 nm,且光栅在宽带波长范围内能够直接激发2阶与3阶轨道角动量模式。通过对光栅施加扭转与应力,能够实现宽带波长调谐。该少模光纤螺旋长周期光栅模式转换器可以实现大范围高转换效率的高阶轨道角动量模式激发。With the development of optical communication networks,the need for high-performance broadband mode converters has become increasingly urgent.In this study,we propose and experimentally fabricate strongly-modulated phase-shifted helical long-period gratings(HLPGs)inscribed in few mode fibers,which can realize the function of all fiber broadband orbital angular momentum mode converters.The strongly-modulated HLPG could be fabricated in few mode fibers with short lengths by exposing the fibers to high-power CO_(2) laser.The fabricated mode converter has a large bandwidth,which could be further increased considerably by introducing a phase shift in the grating.The 10-dB bandwidth of the high-order mode conversion is greater than 200 nm,and the second-and third-order orbital angular momentum modes could be directly excited within the broadband wavelength range.Broadband wavelength tuning could be realized by applying torsion and strain to the gratings.The proposed HLPGs inscribed in the few mode fibers can be adopted as mode converters to realize high-order orbital angular momentum mode excitation with a large wavelength range and high conversion efficiency.

关 键 词：螺旋长周期光纤光栅 少模光纤 轨道角动量 模式转换器 

分 类 号：TN253[电子电信—物理电子学]