上海交通大学 区域光纤通信网与新型光纤通信系统国家重点实验室 智能微波光波融合创新中心, 上海 200240
光子模数转换技术是克服传统电子模数转换技术在采样速率、输入带宽、时钟抖动和比较器模糊等局限性的有效手段。光子模数转换技术为超宽带雷达、超高速示波器、大容量光通信等前沿应用的高速率、大带宽、高精度接收提供了有效解决方案。文章首先简要介绍了光子模数转换技术的技术途径分类及对比, 然后重点介绍作者所在课题组围绕并行解复用光子模数转换系统开展的理论研究与应用研究工作。此外, 分析了集成光子模数转换系统现状并展望了其未来发展思路和关键挑战。最后对全文进行了总结。
光子模数转换技术 高速率 集成化 通道交织 photonic analog-to-digital converter high-speed integration channel-interleaving
Author Affiliations
Abstract
State Key Laboratory of Advanced Optical Communication Systems and Networks, Intelligent Microwave Lightwave Integration Innovation Center (iMLic), Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
A microwave-chip-based coherent multi-frequency RF driver is developed for a channel-interleaved photonic analog-to-digital converter (PADC) system, which comprises a multi-class optical demultiplexer and supports a sampling speed of 40 GSa/s. The generated signals from the RF driver are adjustable in both amplitude and phase. We analyze the relationship between the characteristics of the generated RF driver signals and the demultiplexing performance in theory based on the optical signal-to-distortion ratio (OSDR). It is the most effective parameter to evaluate the performance of the demultiplexer in a PADC system without an electronic analog-to-digital converter. By precisely adjusting the amplitude and phase of signals, the OSDR is optimized. The results verify the compatibility between the RF driver and the PADC system.
photonic analog-to-digital converter multi-frequency RF driver optical signal-to-distortion ratio Chinese Optics Letters
2021, 19(8): 083901
Author Affiliations
Abstract
State Key Laboratory of Advanced Optical Communication Systems and Networks, Intelligent Microwave Lightwave Integration Innovation Center (iMLic), Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
We demonstrate a photonic architecture to enable the separation of ultra-wideband signals. The architecture consists of a channel-interleaved photonic analog-to-digital converter (PADC) and a dilated fully convolutional network (DFCN). The aim of the PADC is to perform ultra-wideband signal acquisition, which introduces the mixing of signals between different frequency bands. To alleviate the interference among wideband signals, the DFCN is applied to reconstruct the waveform of the target signal from the ultra-wideband mixed signals in the time domain. The channel-interleaved PADC provides a wide spectrum reception capability. Relying on the DFCN reconstruction algorithm, the ultra-wideband signals, which are originally mixed up, are effectively separated. Additionally, experimental results show that the DFCN reconstruction algorithm improves the average bit error rate by nearly three orders of magnitude compared with that without the algorithm.
ultra-wideband signal acquisition photonic analog-to-digital converter deep learning Chinese Optics Letters
2020, 18(12): 123901
上海交通大学区域光纤通信网与新型光通信系统国家重点实验室, 智能微波光波融合创新中心(iMLic), 上海 200240
分析了采用多通道并行解复用架构的光子模数转换(PADC)样机用于宽带雷达接收时的通道失配问题,建立了通道失配模型和失配量提取算法,给出了通道失配补偿方法。对比分析角反射器和无人机的回波信号进行通道失配补偿前后的短时傅里叶变换(STFT)谱,结果表明该补偿方法可有效抑制因样机多通道并行解复用架构所导致的固有幅度和延迟失配,从而实现了4 GHz瞬时带宽的X和Ka波段的有效接收。在X和Ka波段下进一步开展了角反射器在近距离静态和远距离动态时的测试和对比实验,结果表明该PADC样机均有效实现了间距约10 cm的角反射器一维成像测量。
光通信 光子模数转换技术 宽带雷达接收 幅度失配 延迟失配 光学学报
2020, 40(16): 1606002
Author Affiliations
Abstract
State Key Laboratory of Advanced Optical Communication Systems and Networks, Intelligent Microwave Lightwave Integration Innovation Center (iMLic), Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
We investigate a channel-interleaved photonic analog-to-digital conversion (PADC) system’s ability to work stably over a long duration with an optimal driving voltage. The influence of optimum bias point drift of a Mach–Zehnder modulator (MZM)-based photonic switch on this system was analyzed theoretically and experimentally. The feasibility of extracting feedback signals from the PADC system was derived. A high-stability channel-interleaved PADC was constructed by extracting a feedback signal from a parallel demultiplexing module to control the MZM-based photonic switch’s driving voltage. Consequently, the amplitude mismatch between the channels was limited to within 0.3 dB over 12 hours of operation.
photonic analog-to-digital converter Mach–Zehnder modulator stability optimization Chinese Optics Letters
2020, 18(1): 012502
上海交通大学区域光纤通信网与新型光通信系统国家实验室, 上海 200030
ADC广泛应用于手持设备, 以及**等领域。电ADC受限于时钟抖动和比较器模糊等关键指标, 性能基本接近理论极限, 提升空间有限。光ADC发挥了光子学的优势, 具有极大的带宽, 能实现远距离传输、远端处理, 是ADC发展的理想方向。光ADC能够很好地突破电ADC理论上的极限, 因此引起广泛关注。利用时间-波长交织、时间拉伸原理进行了光ADC的开发研究, 制做了高速光ADC样机, 进行了实验, 并分享了各项技术的细节。此外, 硅光集成技术将为光ADC技术打开新的窗口。
光子模数转换 时间-波长交织 时间拉伸 飞秒激光 photonic analog-to-digital converter time-wavelength interleaving time-stretch femtosesond laser
