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Dispersion flattened photonic crystal fiber with high nonlinearity for supercontinuum generation at 1.55 μm

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Chinese Optics Letters 2011年第4期9卷 9-13页

作者：郑龙张霞任晓敏马会芳施雷王亚苗黄永清 Key Laboratory of Information Photonics and optical communications Ministry of EducationInstitute of Optical Communications and OptoelectronicsBeijing University of Posts and Telecommunications

A robust design for a photonic crystal fiber （PCF） based on pure silica with small normal dispersion and high nonlinear coefficient for its dual concentric core structure is, presented. This design is suitable for flat broadband supercontinuum （SC） generation in the 1.55-μm region. The numerical results show that the nonlinear coefficient of the proposed eight-ring PCF is 33.8 W^-1·km^-1 at 1550 nm. Ultraflat dispersion with a value between -1.65 and -0.335 ps/（nm·km） is obtained ranging from 1375 to 1625 nm. The 3-dB bandwidth of the SC is 125 nm （1496-1621 nm）, with a fiber length of 80 m and a corresponding input peak power of 43.8 W. The amplitude noise is considered to be related to SC generation. For practical fabrication, the influence of the random imperfections of airhole diameters on dispersion and nonlinearity is discussed to verify the robustness of our design.

关键词： Crystal structure Crystal whiskers Design Dispersions Nonlinear optics optical fiber fabrication Photonic crystals Silica

Artificial intelligence-driven autonomous optical networks: 3S architecture and key technologies

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Science China(Information Sciences) 2020年第6期63卷 7-30页

作者： Yuefeng JI Rentao GU Zeyuan YANG Jin LI Hui LI Min ZHANG State Key Laboratory of Information Photonics and optical communications School of Information and Communication Engineering Beijing University of Posts and Telecommunications State Key Laboratory of Information Photonics and optical communications Institute of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications

In the optical networks, the dynamicity, the complexity and the heterogeneity have dramatically increased owing to the deployment of advanced coherent techniques, and the optical cross-connect technologies and diverse network infrastructures pose great challenges in the optical network management and maintenance for the network operators. In this review, we propose a "3 S" architecture for AI-driven autonomous optical network, which can aid the optical networks operated in "self-aware" of network status, "self-adaptive" of network control, and "self-managed" of network operations. To support these functions, a number of artificial intelligence(AI)-driven techniques have been investigated to improve the flexibility and the reliability from the device aspect to network aspect. Adaptative erbium-doped fiber amplifier(EDFA) controlling is an example for the device aspect, which provides a power self-adaptive capability according to the network *** the link aspect, adaptive fiber nonlinearity compensation, optical monitoring performance and quality of transmission estimation are developed to monitor and alleviate the link-dependent signal impairments in an automatic way. From the network aspect, traffic prediction and network state analysis methods provide the self-awareness, while automatic resource allocation and network fault management powered by AI enhance the self-adaptiveness and self-management capabilities. Benefit from the sufficient network management data,powerful data-mining capability and matured computation units, these AI techniques have great potentials to provide autonomous features for optical networks, including the network resource scheduling and the network customization.

关键词： artificial intelligence optical networks self-aware self-adaptive self-managed

Fabrication and characterization of novel high-speed In GaAs/InP uni-traveling-carrier photodetector for high responsivity

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Chinese Physics B 2015年第10期24卷 612-616页

作者：陈庆涛黄永清费嘉瑞段晓峰刘凯刘锋康超汪君楚房文敬任晓敏 Institute of Information Photonics and optical communications Beijing University of Posts and Telecommunications(BUPT) State Key Laboratory of Information Photonics and optical communications(BUPT)

A top-illuminated circular mesa uni-traveling-carrier photodetector（UTC-PD） is proposed in this paper. By employing Gaussian graded doping in In Ga As absorption layer and In P depleted layer, the responsivity and high speed response characteristics of the device are optimized simultaneously. The responsivity up to 1.071 A/W（the external quantum efficiency of 86%） is obtained at 1550 nm with a 40-μm diameter device under 10-V reverse bias condition. Meanwhile, the dark current of 7.874 n A and the 3-d B bandwidth of 11 GHz are obtained with the same device at a reverse bias voltage of3 V.

关键词： uni-traveling-carrier photodetector device growth and fabrication responsivity 3-dB bandwidth

Defect reduction in GaAs/Si film with InAs quantum-dot dislocation filter grown by metalorganic chemical vapor deposition

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Chinese Physics B 2015年第2期24卷 449-452页

作者：王俊胡海洋邓灿贺云瑞王琦段晓峰黄永清任晓敏 Institute of Information Photonics and optical communications Beijing University of Posts and Telecommunications(BUPT)State Key Laboratory of Information Photonics and Optical Communications(BUPT)

The growth of GaAs epilayers on silicon substrates with multiple layers of InAs quantum dots（QDs） as dislocation filters by metalorganic chemical vapor deposition（MOCVD） is investigated in *** growth conditions of single and multiple layers of QDs used as dislocation filters in GaAs/Si epilayers are *** is found that the insertion of a five-layer InAs QDs into the GaAs buffer layer effectively reduces the dislocation density of GaAs/Si *** with the dislocation density of 5×10^7 cm^-2 in the GaAs/Si sample without QDs,a density of 2×10^6 cm^-2 is achieved in the sample with QD dislocation filters.

关键词： GaAs-on-Si growth dislocation filter quantum dot

Efficient Mechanisms to Improve TCP Performance over OBS Networks

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China communications 2010年第2期7卷 87-91页

作者： Hong Xiaobin, Zhou Jun, Wu Jian, Guo Hongxiang, Zuo Yong, Xu Kun, Lin Jintong Key Laboratory of Information Photonics and optical communications, Ministry of Education Institute of optical communications and Optoelectronics, Beijing University of Posts and Telecommunications, Beijing 100876, China Key Laboratory of Information Photonics and optical communications Ministry of Education Institute of optical communications and Optoelectronics Beijing University of Posts and Telecommunications

Transmission Control Protocol (TCP) performance over optical Burst Switching (OBS) is experimentally investigated on an OBS network testbed, concluding that burst losses will lead to a significant drop in the available TCP bandwidth. Two mechanisms are introduced to improve TCP performance. One is concerning the burst assembly optimization and another is based on the novel assembly and scheduling mechanism to reduce the burst losses.

关键词： OBS ACK TCP burst loss probability scheduling algorithm

Injection-switchable erbium-doped fiber laser with two output ports

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Chinese Optics Letters 2007年第2期5卷 96-98页

作者：陈达如秦山 Centre for optical and Electromagnetic Research Joint Research Centre of Optical CommunicationsZhejiang UniversityHangzhou 310058

An injection-switchable erbium-doped fiber laser （EDFL） with two output ports based on a ring structure is proposed. Wavelength switching together with the switching of the dominating output port of the fiber laser is achieved by controlling the power of a tunable injection laser. The characteristics of the wavelength switching for different levels of the pump laser power and different wavelengths of the injection laser are studied experimentally.

关键词： Injection lasers Switching Wavelength

Multi-wavelength hybrid gain fiber ring laser based on Raman and erbium-doped fiber

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Chinese Optics Letters 2006年第11期4卷 652-654页

作者：秦山唐涌波陈达如 Centre for optical and Electromagnetic Research Joint Research Centre of Optical Communications Zhejiang University Hangzhou 310058 Centre for optical and Electromagnetic Research Joint Research Centre of Optical CommunicationsZhejiang UniversityHangzhou 310058

A stable and uniform multi-wavelength fiber laser based on the hybrid gain of a dispersion compensating fiber as the Raman gain medium and an erbium-doped fiber （EDF） is introduced. The gain competition effects in the fiber Raman amplification （FRA） and EDF amplification are analyzed and compared experimentally. The FRA gain mechanism can suppress the gain competition effectively and make the present multi-wavelength laser stable at room temperature. The hybrid gain medium can also increase the lasing bandwidth compared with a pure EDF laser, and improve the power conversion efficiency compared with a pure fiber Raman laser. OCIS codes： 140.3510, 060.2410, 140.3500, 140.3550.

关键词： Amplification Bandwidth Fiber lasers

Defect Reduction in GaAs/Si Films with the a-Si Buffer Layer Grown by Metalorganic Chemical Vapor Deposition

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Chinese Physics Letters 2015年第8期32卷 165-168页

作者：王俊胡海洋贺云瑞邓灿王琦段晓峰黄永清任晓敏 Institute of Information Photonics and optical communications Beijing University of Posts and Telecommunications State Key Laboratory of Information Photonics and Optical Communications Beijing 100876

The growth of GaAs epilayers on silicon substrates with a thin amorphous silicon （a-Si） buffer layer by met- alorganic chemical vapor deposition is investigated in detail. Combining with the two-step growth method, the growth conditions of the a-Si buffer layer are optimized for growth of high-quality GaAs//Si epilayers. The a-Si buffer layer exhibits the best effect with thickness of 1.8nm and growth temperature of 620℃. It is found that the introduction of this a-Si layer on Si substrates effectively reduces the dislocation density in GaAs//Si films. As compared with the dislocation density of 5 × 107 cm-2 in the GaAs/Si sample without the a-Si layer, a density of 3 × 105 cm-2 is achieved in the sample with the a-Si layer, and the defect reduction mechanism is discussed in detail.

关键词： GALLIUM arsenide CRYSTAL growth DISLOCATION density AMORPHOUS silicon METAL organic chemical vapor deposition

Label swapping and packet transmission of DPSK-labeled PPM signal in optical label switching

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Chinese Optics Letters 2011年第8期9卷 11-15页

作者：师严张琦余重秀忻向军金沧周锐 Institute of Information Photonics and optical communications Beijing University of Posts and Telecommunications

A label swapping scheme of an optical labeled signal with differential phase shift keying （DPSK） for label at 2.5 Gb/s and pulse position modulation （PPM） for payload at 40 Gb/s is demonstrated by simulation. Power penalties of -1.8 and -0.8 dB are achieved for both the payload and label over 80-kin single mode fiber （SMF） transmission. This labeling scheme allows the use of four-wave mixing （FWM） in semiconductor optical amplifier （SOA） to perform label erasure, with advantages of transparence for bit rate, high processing rate, simple architecture, and low cost. Label swapping is demonstrated with appropriate penalties of -3.5 and 0.8 dB for PPM payload and new DPSK label, respectively. To further prove the effectiveness of the proposed scheme, label swapping in the case of using 10-Gb/s DPSK label is also investigated with the nnwer penaltios af tq *** P dR fnr PPM paylnnrl and new dPRIC lnhol

关键词： Four wave mixing Light amplifiers Pulse position modulation Single mode fibers