可实现完美相位保持的OPC-NOLM全光幅度再生  

All-Optical OPC-NOLM Amplitude Regeneration for Intact Phase Preservation

作　　者：郭飚 武保剑 文峰 邱昆 Guo Biao;Wu Baojian;Wen Feng;Qiu Kun(Key Laboratory of Optical Fiber Sensing&Communications,Ministry of Education,School of Information and Communication Engineering,University of Electronic Science and Technology of China,Chengdu 611731,Sichuan,China)

机构地区：[1]电子科技大学信息与通信工程学院光纤传感与通信教育部重点实验室,四川成都611731

出　　处：《光学学报》2023年第3期14-20,共7页Acta Optica Sinica

基　　金：国家自然科学基金(61975027,62001086)。

摘　　要：针对现有相位保持幅度再生方案仍然存在残余相位扰动的问题,提出光学相位共轭器辅助的非线性光纤环形镜(OPCNOLM)方案,该方案可实现多电平全光幅度再生功能,具有相位扰动几乎为零的完美相位保持能力。以16阶正交幅度调制(16QAM)信号为例,仿真了OPCNOLM再生方案性能。研究表明,在输入信噪比为15 dB时,与不使用OPC的单一非线性光纤环形镜(NOLM)情形相比,所提方案的噪声抑制比提高了3.8 dB。Objective Amid the rapid development of modern communication networks,highorder modulation formats,such as quadrature phase shift keying(QPSK)and quadrature amplitude modulation(QAM),have been used widely for large capacity and highspeed data transmission.However,compared with binary signals,highorder modulated signals are easily degraded by channel crosstalk noise and amplified spontaneous emission(ASE)noise.In this case,alloptical regeneration technology can help improve the optical signaltonoise ratio(OSNR)directly in the optical domain.Alloptical amplitude or phase regeneration can usually be achieved by some optical structures with nonlinear effects,such as the nonlinear optical loop mirror(NOLM),the MachZehnder interferometer(MZI),the phasesensitive amplifier(PSA),and the semiconductor optical amplifier(SOA).In the process of alloptical amplitude regeneration,the conversion of amplitude noise to phase perturbation is always adopted to a certain extent.Therefore,phasepreserving amplitude regeneration(PPAR)schemes have been put forward for QPSK and QAM signals.Nevertheless,phase perturbation(larger than 3.8°)remains.The objective of the paper is to present an intact PPAR scheme without phase perturbation.Methods This paper proposes an optical phase conjugator(OPC)-assisted NOLM(OPCNOLM)PPAR scheme,in which the reflected signal from the NOLM unit is used to achieve a stepwise power transfer function(PTF)and the OPC is utilized to compensate for the phase perturbation.The optical field output from the OPCNOLM regenerator is derived and used to analyze the phasepreserving mechanism of the regenerator from the two aspects of amplitude and phase.The structural parameters of the OPCNOLM regenerator are optimized by the PTF and phase perturbation curves.Then,an OPCNOLM regenerator simulation platform for optical 16QAM signals is built to verify the intact PPAR performance of the proposed scheme by comparison with the NOLM scheme.Results and Discussions According to the PTF and amplitudetophase conversion characteri

关 键 词：光纤光学 全光再生 非线性光环镜 相位保持 幅度再生 多级调制格式 

分 类 号：O437.[机械工程—光学工程]