北京邮电大学信息光子学与光通信研究院国家重点实验室, 北京 100876
介绍了一种采用新型调制解调方案的全光纤电流互感器。该方案采用归零方波调制相位调制器，以正弦波信号作为本振信号实现模拟相干解调，对采样信号做数字信号处理(有限脉冲响应滤波、滑动平均滤波)完成阶梯波反馈补偿并实现电流闭环检测。对实验结果的分析表明，该方案能实现大电流闭环检测，在室温条件下、额定电流1000 A 时达到IEC 60044-8:2002标准0.2级，具有实际应用价值。
光纤光学 全光纤电流互感器 归零方波 模拟相干解调 闭环检测
1 北京邮电大学 信息光子学与光通信国家重点实验室,北京 100876
2 工业和信息化部电信研究院,北京 100191
开发了新的自动对接方法,设计了基于阈值的折返遍历搜索算法(RTS)与二分数据截断(BTDT)搜索算法,实现了六自由度耦合平台的四自由度的自动对接。折返遍历搜索算法精度高,可设定不同步长实现不同精度要求;二分数据截断算法搜索速度快,可快速接近最高点。实验结果表明,波导器件的纤到纤损耗可在8 min 内调节至8~9 dB(包括波导传输损耗,人工对准需在半小时以上才可达到8~9 dB),耦合系统稳定性可保持15~20 min。与自动测试系统配合使用,在8 min 内即可进行2 200 点的波长扫描与功率扫描,自动耦合系统具有实用性、稳定性和良好效果。
自动耦合 Matlab 仪器控制 折返遍历搜索 二分数据截断搜索 自动测试 auto coupling MATLAB instrument control return-traversal search BTDT auto testing
Author Affiliations
Abstract
State Key Laboratory of Information Photonics & Optical Communications (Beijing University of Posts and Telecommunications), P.O. Box 55 (BUPT), Beijing 100876, China
Microwave photonics (MWPs) uses the strength of photonic techniques to generate, process, control, and distribute microwave signals, combining the advantages of microwaves and photonics. As one of the main topics of MWP, radio-over-fiber (RoF) links can provide features that are very difficult or even impossible to achieve with traditional technologies. Meanwhile, a considerable number of signal-processing subsystems have been carried out in the field of MWP as they are instrumental for the implementation of many functionalities. However, there are still several challenges in strengthening the performance of the technology to support systems and applications with more complex structures, multiple functionality, larger bandwidth, and larger processing capability. In this paper, we identify some of the notable challenges in MWP and review our recent work. Applications and future direction of research are also discussed.
Radio frequency photonics Fiber optics and optical communications Fiber optics links and subsystems Networks combinatorial network design Metrology Photonics Research
2014, 2(4): 04000B54
Author Affiliations
Abstract
We propose a third-order intermodulation distortion (IMD3) compensation scheme based on the bidirectional modulation of 2-Ch phase modulator (PM). We realize the destructive combination of IMD3 by using different modulation efficiencies and appropriately adjusting the input optical power ratio to satisfy a fixed relationship with modulation efficiency. The primary advantage of this scheme is that out-of-phase IMD3 is introduced using only one 2-Ch PM, thereby resulting in the cancellation of IMD3. Up to 27-dB suppression in IMD3 is experimentally demonstrated—a feature that will be useful in low-distortion analog optical transmission.
060.0060 Fiber optics and optical communications 060.2330 Fiber optics communications Chinese Optics Letters
2013, 11(8): 080603
Author Affiliations
Abstract
An improved optoelectronic oscillator scheme for an optical time division multiplexing (OTDM) system based on cascaded Mach–Zehnder modulator (MZM) and polarization modulator (PolM) is experimentally investigated. The system can simultaneously realize clock recovery and demultiplexing. With the MZM working at peak point to generate return-to-zero-33 optical pulses and the PolM working as an equivalent intensity modulator, a high-quality clock signal with 35-fs timing jitter is extracted from the 160-GBaud OTDM-differential quaternary phase-shift keying signal. Narrow short optical switch gates (4 ps) are also generated to demultiplex 160-GBaud signals to 40-GBaud signals. Error-free performance is achieved with 2.4-dB power penalty in the worst case.
060.2330 Fiber optics communications 130.4110 Modulators Chinese Optics Letters
2013, 11(5): 050602
Author Affiliations
Abstract
A novel photonic-assisted approach to microwave frequency measurement is proposed and experimentally demonstrated. The proposed scheme is based on the frequency-to-power mapping with different transmission responses. A polarizer is used in one output branch of a phase modulator to simultaneously implement phase modulation and intensity modulation. Owing to the complementary nature of the transmission responses and the Mach-Zehnder interferometers (MZIs), this scheme theoretically provides high resolution and tunable measurement range. The measurement errors in the experimental results can be kept within 0.2 GHz over a frequency range from 0.1 to 5.3 GHz.
060.5625 Radio frequency photonics 060.4510 Optical communications Chinese Optics Letters
2013, 11(2): 020604
Author Affiliations
Abstract
The effects of optical losses on a directly-modulated radio-over-fiber (RoF) system used for distributed antenna networks are determined. The results show that with a properly designed bidirectional amplifier, the RoF link can tolerate over 20 and 16 dB of optical losses for down- and up-links, respectively. Simulation results are also consistent with the experimental data. These findings can contribute to the design of RoF distributed antenna systems with different topologies.
060.4510 Optical communications 060.5625 Radio frequency photonics Chinese Optics Letters
2013, 11(2): 020603
Author Affiliations
Abstract
An all-optical serial-to-parallel converter (SPC) utilizing two cascaded phase modulators and optical band-pass filters (OBPFs) is experimentally investigated and applied to demultiplex an 80-GBd optical time-division multiplexing (OTDM) return-to-zero (RZ) differential quadrature phase-shift keying (QPSK) signal. Two 40-GBd OTDM tributaries are error-free demultiplexed with a power penalty of approximately 4 dB in the worst case. With its advantages of compact structure, high speed, low power penalty, simultaneous two-tributary operation, and no assistance from a light source, the SPC has potential for use in future OTDM networks. However, the performance of the SPC still needs improvement.
320.7080 Ultrafast devices 320.1590 Chirping 060.5060 Phase modulation Chinese Optics Letters
2012, 10(11): 113201
Author Affiliations
Abstract
The impact of channel occupancies on polarization division multiplexed quadrature phase-shift keying (PDM-QPSK)/on-off keying (OOK) hybrid systems is investigated numerically over a dispersion-managed transmission link. In addition to keep large residual dispersion per span, we find that suitable channel occupancy also help to improve the nonlinear tolerance of such hybrid systems significantly. About 2.4-dBm more nonlinear threshold (NLT) and 75% increase of transmission reach can be obtained under suitable channel plan for 112-Gb/s PDM-QPSK/OOK hybrid systems.
060.1660 Coherent communications 060.2330 Fiber optics communications 060.4510 Optical communications Chinese Optics Letters
2012, 10(s1): S10603
Author Affiliations
Abstract
A novel scalable and integrated design that supports optical multicast and burst amplification is proposed and demonstrated experimentally. The powers of incoming signals can be tuned to optimize the results of burst amplification and replication. Experimental results also show that erbium-doped optical Fiber amplication (EDFA) transients can be suppressed to an equally low level regardless of the burst parameters. Extended structure designs are further proposed to satisfy the need of mass replication of multicast signals.
060.1155 All-optical networks 060.2320 Fiber optics amplifiers and oscillators 060.4255 Networks, multicast Chinese Optics Letters
2012, 10(7): 070606
