红外与激光工程
2023, 52(9): 20220814
1 空军航空维修技术学院,湖南 长沙 410124
2 复旦大学信息科学与工程学院,上海 200433
本文首先从理论上分析了在共极化双泵浦方案中,波长转换不会改变概率整形(PS)信号的概率分布,并且正交频分复用(OFDM)信号子载波的顺序可以保持不变的原因。然后,通过实验验证了全光波长转换后,PS-64QAM-OFDM信号通过高非线性光纤在零差相干检测系统中的传输。最后,通过实验证明,当波特率为20 Gbaud、误码率为1×10-2时,普通64QAM信号的光信噪比(OSNR)损耗为1 dB,PS-64QAM信号的OSNR损耗改善了0.5 dB。
光纤光学与光通信 概率整形 正交频分复用 波长变换 非线性光纤 激光与光电子学进展
2023, 60(19): 1906001
光子学报
2022, 51(10): 1019003
Author Affiliations
Abstract
1 The Chinese University of Hong Kong, Department of Electronic Engineering, Shatin, Hong Kong SAR, China
2 University of Science and Technology of China, CAS Key Laboratory of Quantum Information, Hefei, China
3 University of Science and Technology of China, CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei, China
Modern information networks are built on hybrid systems working at disparate optical wavelengths. Coherent interconnects for converting photons between different wavelengths are highly desired. Although coherent interconnects have conventionally been realized with nonlinear optical effects, those systems require demanding experimental conditions, such as phase matching and/or cavity enhancement, which not only bring difficulties in experimental implementation but also set a narrow tuning bandwidth (typically in the MHz to GHz range as determined by the cavity linewidth). Here, we propose and experimentally demonstrate coherent information transfer between two orthogonally propagating light beams of disparate wavelengths in a fiber-based optomechanical system, which does not require phase matching or cavity enhancement of the pump beam. The coherent process is demonstrated by interference phenomena similar to optomechanically induced transparency and absorption. Our scheme not only significantly simplifies the experimental implementation of coherent wavelength conversion but also extends the tuning bandwidth to that of an optical fiber (tens of THz), which will enable a broad range of coherent-optics-based applications, such as optical sensing, spectroscopy, and communication.
cavity optomechanics coherent wavelength conversion optomechanically induced transparency Advanced Photonics
2022, 4(5): 056003
1 西安邮电大学电子工程学院,陕西 西安 710121
2 中国船舶重工集团第705研究所水下信息与控制重点实验室,陕西 西安 710077
基于四波混频效应的全光波长转换技术在解决全光信号处理问题中至关重要。波长转换是通过波长转换器将受阻的数据转换到其它空闲波长上进行输出,可解决资源分配不足、通信质量降低的问题。硅基波导及光子晶体光纤等都可用于波长转换,但对于短距离通信,硅基波导更具优势。构建了一种新型MEH-PPV硅基光波导,通过有限元法对其进行了色散调控,分析了该波导在最佳结构下的相位失配特性及非线性系数的变化特性。结合该波导的传输损耗、相位失配特性以及非线性系数,建立了基于泵浦简并条件下的四波混频数学模型,分析了不同信号光功率、泵浦光功率以及波导长度下的波长转换效果。结果表明:采用MEH-PPV材料作为夹层的slot硅基波导,最大波长转换效率约为16 dB,其转换带宽为400 nm左右,在全光信号处理领域具有广泛的应用前景。
光学器件 波长转换 全光信号处理 四波混频 slot硅基波导 MEH-PPV 激光与光电子学进展
2022, 59(17): 1723001
Author Affiliations
Abstract
College of Opto-Electronic Engineering, Changchun University of Science and Technology, Changchun 130022, China
We fully demonstrate the special requirements of a mid-infrared all-optical wavelength converter. The construction mechanism of a 2.05 µm all-optical wavelength converter based on the single-wall carbon nanotube (SWCNT) is proposed. Systematic experiments are carried out, and the converter device is successfully developed. With the assistance of SWCNT-coated microfiber, the conversion efficiency up to is realized, and the tuning range can reach 9.72 nm. The experimental results verify the correctness of the proposed mechanism and the feasibility of the converter device so that it can be a new technical approach for all-optical wavelength conversion beyond 2 µm. We believe the research can extend the application of this composite waveguide in the field of all-optical communication.
all-optical wavelength conversion single-wall carbon nanotube 2.05 µm microfiber fiber laser Chinese Optics Letters
2022, 20(6): 060602
Author Affiliations
Abstract
1 Qingdao University, College of Physics Science, Center for Marine Observation and Communications, Qingdao, China
2 Shandong University, School of Physics, State Key Laboratory of Crystal Materials, Jinan, China
Femtosecond laser inscription or writing has been recognized as a powerful technique to engineer various materials toward a number of applications. By efficient modification of refractive indices of dielectric crystals, optical waveguides with diverse configurations have been produced by femtosecond laser writing. The waveguiding properties depend not only on the parameters of the laser writing but also on the nature of the crystals. The mode profile tailoring and polarization engineering are realizable by selecting appropriate fabrication conditions. In addition, regardless of the complexity of crystal refractive index changes induced by ultrafast pulses, several three-dimensional geometries have been designed and implemented that are useful for the fabrication of laser-written photonic chips. Some intriguing devices, e.g., waveguide lasers, wavelength converters, and quantum memories, have been made, exhibiting potential for applications in various areas. Our work gives a concise review of the femtosecond laser-inscribed waveguides in dielectric crystals and focuses on the recent advances of this research area, including the fundamentals, fabrication, and selected photonic applications.
femtosecond laser writing femtosecond laser inscription optical waveguides dielectric crystals laser crystals nonlinear optical crystals waveguide lasers frequency/wavelength conversion quantum photonic chip quantum memories Advanced Photonics
2022, 4(2): 024002
1 曲阜师范大学物理工程学院山东省激光偏光与信息技术重点实验室, 山东 曲阜 273165
2 中国科学院上海微系统与信息技术研究所中国科学院太赫兹固态技术重点实验室, 上海 200050
量子点半导体光放大器(QD-SOA)具有皮秒级的增益恢复时间和超快的载流子浓度恢复等特点,光子晶体(PC)与QD-SOA结合后具有强非线性效应、低吸收损耗、高功率传输和低功耗等优点。研究了光子晶体-量子点半导体光放大器(PC-QDSOA)的波长转换特性,详细分析了最大模式增益、泵浦光功率、探测光功率、有源区长度对PC-QDSOA波长转换Q因子的影响及注入电流、泵浦光功率、探测光功率、有源区长度与PC-QDSOA波长转换消光比的关系,并将PC-QDSOA仿真结果与QD-SOA的仿真结果进行比较。结果显示PC-QDSOA的Q因子和消光比的数值总是大于QD-SOA,说明PC-QDSOA比QD-SOA的输出信号质量更好,信号传输效率更高,转换性能更优越。研究结果对PC-QDSOA的应用具有一定的指导意义。
光通信 量子点半导体光放大器 光子晶体 波长转换 Q因子 消光比
1 贵州大学物理学院, 贵州 贵阳 550025
2 中国科学院高能物理研究所, 北京 100049
3 湖北泰晶科技股份有限公司, 湖北 随州 441300
对基于半导体光放大器交叉增益调制效应的全光波长转换后的信号啁啾特性进行了分析。通过数值模拟方法研究了归零码和非归零码经过波长变换后的啁啾及波形变化特征,并研究了两种码型信号的啁啾与光功率、信号速率、波长、信号光消光比、码元波形参数、半导体光放大器偏置电流的关系。结果表明,当码元数量较少时,归零码与非归零码相比,信号会有更大的啁啾;上升沿(下降沿)占比小于10%信号周期时,转换光波形均会出现明显的过冲(下冲)现象,过冲(下冲)导致了转换光的啁啾峰值大于啁啾谷值;增加偏置电流会缓减过冲现象,同时会增加交叉增益效应,偏置电流在不同阶段对啁啾的影响效果是不同的;增大数据传输速率会使载流子浓度的变化加快,导致啁啾峰值(谷值)增加。光注入下增益峰值红移会使转换光啁啾对参考光波长和信号波长具有敏感性;消光比的变化也会改变半导体光放大器中的载流子浓度,进而影响转换光啁啾;增大参考光功率或者降低信号光功率能够导致啁啾降低。研究结果对基于半导体光放大器交叉增益调制效应的全光波长转换系统的实用化具有重要的意义。
光学器件 半导体光放大器 交叉增益调制 波长变换 啁啾 归零码 非归零码 光学学报
2021, 41(24): 2423001
光学 精密工程
2021, 29(10): 2296