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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

All-optical neuromorphic devices: materials, working mechanism,and applications

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Science China Chemistry 2025年

作者： Song Wang Hao Chen Hui Huang College of Materials Science and Opto-Electronic Technology Center of Materials Science and Optoelectronics Engineering CAS Center for Excellence in Topological Quantum Computation CAS Key Laboratory of Vacuum Physics University of Chinese Academy of Sciences College of Chemistry and Molecular Engineering Peking University

Traditional von Neumann computing, with physical separation of memory and processing units, cannot satisfy the development of artificial intelligence and cloud computing. Neuromorphic computing, inspired by the human brain, has drawn much ***-optical neuromorphic (AON) devices employ optical signals as information carriers and leverage the neuromorphic functions to implement fast operation speed, low energy consumption, and high bandwidth of neuromorphic computing. Here, we discuss the recent progress in AON devices, including materials, device performance, working mechanisms, and applications. Moreover,the advantages and limitations of AON are presented and discussed. Finally, the perspective of AON devices points out the future research direction of neuromorphic computing.

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Strain distributions and electronic structure of three-dimensional InAs/GaAs quantum rings

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Chinese Physics B 2009年第11期18卷 4667-4675页

作者：刘玉敏俞重远贾博雍徐子欢姚文杰陈智辉芦鹏飞韩利红 Institute of optical Communication and optoelectronics Key Laboratory of Information Photonics and optical communications (Beijing University of Posts and Telecommunications) Ministry of Education

This paper presents a finite element calculation for the electronic structure and strain distribution of self-organized InAs/GaAs quantum rings. The strain distribution calculations are based on the continuum elastic theory. An ideal three-dimensional circular quantum ring model is adopted in this work. The electron and heavy-hole energy levels of the InAs/GaAs quantum rings are calculated by solving the three-dimensional effective mass SchrSdinger equation including the deformation potential and piezoelectric potential up to the second order induced by the strain. The calculated results show the importance of strain and piezoelectric effects, and these effects should be taken into consideration in analysis of the optoelectronic characteristics of strain quantum rings.

关键词： quantum ring strain distribution electronic structure

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

Polarisation-sensitive four-wave mixing and soliton self-frequency shift effect in the highly birefringent photonic crystal fibre

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Chinese Physics B 2010年第7期19卷 344-349页

作者：苑金辉桑新柱余重秀忻向军李曙光周桂耀侯蓝田 Key Laboratory of Information Photonics and optical communications Ministry of EducationInstitute of Optical Communication and OptoelectronicsBeijing University of Posts and Telecommunications Institute of Infrared optical Fibers and Sensors College of Information Science and EngineeringYanshan University

By adjusting the polarisation state of the pump at 805 nm parallel to slow （x） and fast （y） axes of the highly birefringent photonic crystal fibre with zero dispersion wavelengths 790 nm and 750 nm, this paper demonstrates the efficient polarisation-sensitive four wave mixing involved in pump, anti-Stokes and Stokes signals and soliton self- frequency shift effects induced by the phase-matching between red-shifted solitons and blue-shifted dispersive waves. If the reduction of coupling efficiency to the circular pump laser mode or other circular fibres due to asymmetry of the core is neglected, more than 98% of the total input power is kept in a single linear polarisation. Controlled dispersion characteristic of the doublet of fundamental guided-modes results in achieving light field strongly confined in principal axes of photonic crystal fibre, and enhancing the corresponding nonlinear-optical process through the remarkable nonlinear birefringence.

关键词： highly birefringent photonic crystal fibre four wave mixing soliton self-frequency shift phase-matching

Broad and ultra-flattened supercontinuum generation in the visible wavelengths based on the fundamental mode of photonic crystal fibre with central holes

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Chinese Physics B 2011年第5期20卷 294-299页

作者：苑金辉桑新柱余重秀忻向军申向伟张锦龙周桂耀李曙光侯蓝田 Key Laboratory of Information Photonics and optical communications(BUPT) of Ministry of Education Institute of Optical Communication and OptoelectronicsBeijing University of Posts and Telecommunications Institute of Infrared optical Fibers and Sensors College of Information Science and EngineeringYanshan University

By coupling a train of femtosecond pulses with 100 fs pulse width at a repetition rate of 76 MHz generated by a mode-locked Ti： sapphire laser into the fundamental mode of photonic crystal fibre （PCF） with central holes fabricated through extracting air from the central hole, the broad and ultra-flattened supercontinuum （SC） in the visible wavelengths is generated. When the fundamental mode experiences an anomalous dispersion regime, three phases in the SC generation process are primarily presented. The SC generation （SCG） in the wavelength range from 470 nm to 805 nm does not emerge significant ripples due to a higher pump peak power and the corresponding mode fields at different wavelengths are observed using Bragg gratings. The relative intensity fluctuations of output spectrum in the wavelength ranges of 530 nm to 640 nm and 543 nm to 590 nm are only 0.028 and 0.0071, respectively.

关键词： photonic crystal fibre (PCF) fundamental mode broad and ultra-flattened supercontinuum visible wavelengths

Theoretical investigation of band-gap and mode characteristics of anti-resonance guiding photonic crystal fibres

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Chinese Physics B 2011年第2期20卷 302-310页

作者：苑金辉桑新柱余重秀忻向军张锦龙周桂耀李曙光侯蓝田 Key Laboratory of Information Photonics and optical communications (BUPT) Ministry of Education Institute of optical Communication and optoelectronics Beijing University of Posts and Telecommunications Institute of Infrared optical Fibres and Sensors College of Information Science and EngineeringYanshan University

With the full-vector plane-wave method （FVPWM） and the full-vector beam propagation method （FVBPM）, the dependences of the band-gap and mode characteristics on material index and cladding structure parameter in anti- resonance guiding photonic crystal fibres （ARGPCFs） are sufficiently analysed. An ARGPCF operating in the near- infrared wavelength is shown. The influences of the high index cylinders, glass interstitial apexes and silica structure on the characteristics of band-gaps and modes are deeply investigated. The equivalent planar waveguide theory is used for analysing such an ARGPCF filled by the isotropic materials, and the resonance and the anti-resonance characteristics r：~n h~ w~｜] r^r~dlrtpd

关键词： anti-resonance guiding photonic crystal fibres full-vector plane-wave method full-vector beam propagation method band-gap and mode characteristics

Memcomputing: fusion of memory and computing

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Science China(Information Sciences) 2018年第6期61卷 159-161页

作者： Yi LI Yaxiong ZHOU Zhuorui WANG Xiangshui MIAO Wuhan National Research center for optoelectronics School of Optical and Electronic InformationHuazhong University of Science and Technology

In this world of ubiquitous computing,the contemporary electronic digital computer has become an essential machine that is available anytime and *** systems come in various forms,including desktops,laptops,tablets,mob... 详细信息

关键词： In fusion of memory and computing Memcomputing

Thermal stress reduction of GaAs epitaxial growth on V-groove patterned Si substrates

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Chinese Physics B 2021年第1期30卷 359-364页

作者： Ze-Yuan Yang Jun Wang Guo-Feng Wu Yong-Qing Huang Xiao-Min Ren Hai-Ming Ji Shuai Luo State Key Laboratory of Information Photonics and optical communications Beijing University of Posts and TelecommunicationsBeijing 100876China center of Materials Science and optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

We investigate the thermal stresses for GaAs layers grown on V-groove patterned Si substrates by the finite-element method. The results show that the thermal stress distribution near the interface in a patterned substrate is nonuniform,which is far different from that in a planar substrate. Comparing with the planar substrate, the thermal stress is significantly reduced for the Ga As layer on the patterned substrate. The effects of the width of the V-groove, the thickness, and the width of the SiO_(2) mask on the thermal stress are studied. It is found that the SiO_(2) mask and V-groove play a crucial role in the stress of the Ga As layer on Si substrate. The results indicate that when the width of V-groove is 50 nm, the width and the thickness of the SiO_(2) mask are both 100 nm, the Ga As layer is subjected to the minimum stress. Furthermore,Comparing with the planar substrate, the average stress of the Ga As epitaxial layer in the growth window region of the patterned substrate is reduced by 90%. These findings are useful in the optimal designing of growing high-quality Ga As films on patterned Si substrates.

关键词： GaAs on Si thermal stress V-groove finite-element method