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Electromagnetically induced transparency-like effect in a lithium niobate resonator via electronic control

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Photonics Research 2023年第5期11卷 773-779页

作者： LIU YANG YONGYONG ZHUANG YIFAN zhang YAOJING zhang shuangyou zhang ZHUO XU PASCAL DEL’HAYE XIAOYONG WEI Electronic Materials Research Laboratory Key Laboratory of the Ministry of Education&International Center for Dielectric ResearchSchool of Electronic Science and EngineeringFaculty of Electronic and Information EngineeringXi’an Jiaotong UniversityXi’an 710049China Max Planck Institute for the Science of Light 91058 ErlangenGermany

In this study,we theoretically proposed a method to achieve an electromagnetically induced transparency(EIT)-like effect in a whispering gallery mode resonator(WGMR)and experimentally validated the method in a lithium niobate(LN)*** from the electro-optic and inverse piezoelectric effects of the LN material,two modes of the LN WGMR that are close in frequency can be tuned at different tuning rates,resulting in EIT-like resonance *** varying the electric field applied to the LN WGMR,the full dynamic of the EIT-like phenomenon can be precisely *** experimental results agreed well with the calculations based on the coupled mode ***,we observed a hysteresis resulting from the photorefractive effect of *** believe our proposed method and demonstrated devices offer a way to control an EIT-like effect,which could have potential applications in light storage,quantum information processing,and enhanced sensing techniques.

关键词： resonator tuning effect

All-fiber-photonics-based ultralow-noise agile frequency synthesizer for X-band radars

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Photonics Research 2018年第1期9卷 12-17页

作者： JUAN WEI DOHYEON KWON shuangyou zhang SHILONG PAN AND JUNGWON KIM School of Mechanical and Aerospace Engineering Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 South Korea Key Laboratory of Radar Imaging and MicrowavePhotonics Ministry of Education Nanjing University o-f Aeronautics and Astronautics (NUAA) Nanjing 210016 China

We propose and demonstrate an agile X-band signal synthesizer with ultralow phase noise based on all-fiberphotonic techniques for radar applications. It shows phase noise of-145 dBc∕Hz(-152 dBc∕Hz) at 10 kHz(100 kHz) offset frequency for 10 GHz carrier frequency with integrated RMS timing jitter between 7.6 and 9.1 fs(integration bandwidth: 10 Hz–10 MHz) for frequencies from 9 to 11 GHz. Its frequency switching time is evaluated to be 135 ns with a 135 pHz frequency tuning resolution. In addition, the X-band linearfrequency-modulated signal generated by the proposed synthesizer shows a good pulse compression ratio approximating the theoretical value. In addition to the ultrastable X-band signals, the proposed synthesizer can also provide 0–1 GHz ultralow-jitter clocks for analog-to-digital converters(ADC) and digital-to-analog converters(DAC) in radar systems and ultralow-jitter optical pulse trains for photonic ADC in photonic radar *** proposed X-band synthesizer shows great performance in phase stability, switching speed, and modulation capability with robustness and potential low cost, which is enabled by an all-fiber-photonics platform and can be a compelling technology suitable for future X-band radars.

关键词： X波段信号合成器雷达通讯技术发展现状

Coherent suppression of backscattering in optical microresonators

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Light(Science & Applications) 2020年第1期9卷 16-23页

作者： Andreas O.Svela Jonathan M.Silver Leonardo Del Bino shuangyou zhang Michael T.M.Woodley Michael R.Vanner Pascal Del’Haye National Physical Laboratory Teddington TW110LWUK Blackett Laboratory Imperial College LondonLondon SW72AZUK Clarendon Laboratory University of OxfordOxford OX13PUUK City University of London London EC1V 0HBUK Max Planck Institute for the Science of Light StaudtstaBe 291058 ErlangenGermany Heriot-Watt University Edinburgh EH144ASUK Friedrich Alexander University Erlangen-Nuremberg 91058 ErlangenGermany

As light propagates along a waveguide,a fraction of the field can be reflected by Rayleigh *** high-qualityfactor whispering-gallery-mode microresonators,this intrinsic backscattering is primarily caused by either surface or bulk material *** several types of microresonator-based experiments and applications,minimal backscattering in the cavity is of critical importance,and thus,the ability to suppress backscattering is *** demonstrate that the introduction of an additional scatterer into the near field of a high-quality-factor microresonator can coherently suppress the amount of backscattering in the microresonator by more than 30 *** method relies on controlling the scatterer position such that the intrinsic and scatterer-induced backpropagating fields destructively *** technique is useful in microresonator applications where backscattering is currently limiting the performance of devices,such as ring-laser gyroscopes and dual frequency combs,which both suffer from injection ***,these findings are of interest for integrated photonic circuits in which back reflections could negatively impact the stability of laser sources or other components.

关键词： resonator waveguide scatter

The research of miniaturization CPT Rb atomic clocks

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The research of miniaturization CPT Rb atomic clocks

第四届中国卫星导航学术年会

作者： shuangyou zhang Zhong Wang Jianye Zhao School of Electronics Engineering and Computer Science Peking University

Based on current situation of the study in this area, our work will introduce a miniature CPT atomic clock system with small physical size, high stability and lower power consumption. The use of our original innovational technology to fabricate small cells can avoid the complexity and difficulty of the anodic bonding technology. By this technology, we could accomplish the objective to minimize the occupied volume of the physical part of the system to 1 cm3 . The single FPGA chip is the main part of the control circuit to accomplish the slower start-up of the laser, two necessary locking loops to make the system work, and the temperature control logic. Our 3.035GHz RF signal is generated from a TCXO via the technology of DDS. Our prototype is a significant progress to realize CSAC with the use of the single FPGA chip. We demonstrate our CPT clock prototype with the volume less than 100 cm3 . This prototype has frequency instability of 1×10-10 for 1s and 3×10-11 for 1000s.

关键词： CPT. CSAC. FPGA. Rb. Instability

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基于模拟移相补偿的长距离光纤频率传输

中国激光 2015年第4期42卷 124-128页

作者：任丽霞章双佑钱程赵建业北京大学信息科学技术学院北京100871

为实现频率信号在长距离光纤上的高精度传输,设计了一个纯电的相位补偿系统,其补偿速度较快,范围较大,且便于模块化。该系统主要利用两次模拟移相抵消返回信号中所引入的双程相位抖动来进行补偿,结构简单,易于调试。通过引入数字信号处... 详细信息

为实现频率信号在长距离光纤上的高精度传输,设计了一个纯电的相位补偿系统,其补偿速度较快,范围较大,且便于模块化。该系统主要利用两次模拟移相抵消返回信号中所引入的双程相位抖动来进行补偿,结构简单,易于调试。通过引入数字信号处理和比例积分微分(PID)控制算法,可以提高系统的补偿精度和工作稳定性。最后,利用该系统在100 km的实验室光纤上进行100 MHz频率信号的传输实验,得到的频率稳定度为3.9×10-14/s和1.1×10-16/4000 s,证明了此方法在长距离光纤频率传输中的可行性,为导航、航天以及空间探测等领域中远距离站点的协同工作,提供频率同步支持。

关键词：光纤光学频率传输相位抖动补偿模拟移相长距离

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高中物理教学如何培养学生的探究能力

天津教育 2021年第7期 83-85页

作者：张双有甘肃省张掖市高台县第一中学

高中物理教学要注重实验教学和课堂教学相结合,提高学生的探究能力。科学合理的实验教学有利于学生在丰富的物理知识海洋中感知物理知识的魅力,也能够对学生的动手能力和科学的思维能力产生积极的影响,能够激励学生独立思考问题、积极... 详细信息

高中物理教学要注重实验教学和课堂教学相结合,提高学生的探究能力。科学合理的实验教学有利于学生在丰富的物理知识海洋中感知物理知识的魅力,也能够对学生的动手能力和科学的思维能力产生积极的影响,能够激励学生独立思考问题、积极主动地探究问题,在探究问题的过程中,逐渐形成独立思考的能力、自主探究的能力。

关键词：高中物理探究学习综合能力

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一种用于高精度频率传输的光纤功率补偿技术

应用光学 2015年第2期36卷 332-336页

作者：罗国勇章双佑任全胜赵建业北京大学电路与系统实验室北京100871

为了抑制偏振态漂移带来的功率变化给传输稳定度造成的影响,设计了一种能够快速补偿偏振变化的频率传输系统。该系统将锁模光作为光源,结合PID控制器反馈调节的原理,利用光功率放大器(EDFA)、起偏器、可变光功率衰减器(VOA)和单片机实... 详细信息

为了抑制偏振态漂移带来的功率变化给传输稳定度造成的影响,设计了一种能够快速补偿偏振变化的频率传输系统。该系统将锁模光作为光源,结合PID控制器反馈调节的原理,利用光功率放大器(EDFA)、起偏器、可变光功率衰减器(VOA)和单片机实现。实验结果表明:该系统能够有效抑制偏振态随着环境改变而发生的漂移,经过10km传输之后的输出光功率稳定度达到1×10-5,与自由漂相比提高了200倍。将整个系统应用在光梳频率传输系统中,可以提高系统的鉴相精度,在5GHz的传输频率上,可以有效消除偏振态变化引入的~50fs的相位抖动。

关键词：偏振态功率补偿锁模光 PID控制

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拉姆塞光梳光谱学

激光与光电子学进展 2015年第11期52卷 263-267页

作者：章双佑张宇杨晚鹏赵建业北京大学信息科学技术学院北京100871

飞秒光梳为精密光谱测量领域带来了革命性的进展,不仅为射频与光频建立了直接的联系,将光谱测量精度提高至17位,而且还可以直接用于光谱测量,产生了一门新的学科——直接光梳光谱学(DFCS)。在DFCS中,光梳脉冲能量放大和非线性频率变换... 详细信息

飞秒光梳为精密光谱测量领域带来了革命性的进展,不仅为射频与光频建立了直接的联系,将光谱测量精度提高至17位,而且还可以直接用于光谱测量,产生了一门新的学科——直接光梳光谱学(DFCS)。在DFCS中,光梳脉冲能量放大和非线性频率变换是不可或缺的手段,但是传统的脉冲放大、高次谐波产生过程会导致光梳的频率分辨率下降,精度和能量难以兼得。本文报道了激光光谱学中的重大进展——拉姆塞光梳光谱学,该技术结合了两个诺贝尔奖概念,可实现光谱的高准确度、高分辨率测量。

关键词：光谱学拉姆塞光梳直接光梳光谱学拉姆塞光梳光谱学

Diatomic Pd catalyst with conjugated backbone for synergistic electrochemical CO_(2)reduction

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Nano Research 2024年第6期17卷 4850-4855页

作者： Wenxuan zhang Mengran zhang Hongjuan Wang Wen zhang Min zhang MOE International Joint Laboratory of Materials Microstructure Institute for New Energy Materials and Low Carbon TechnologiesSchool of Materials Science and EngineeringTianjin University of TechnologyTianjin 300384China Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion School of Chemistry and Chemical EngineeringTianjin University of TechnologyTianjin 300384China

Double-site catalysts have attracted widespread attention in the field of electrocatalysis due to their high metal loading,adjustable active centres,and electronic valence ***,the development of bimetallic sites catalysts that coordinate with definite atoms is still in the exploratory ***,we designed and synthesized a bimetallic palladium complex(BPB-Pd_(2))with conjugated *** supported BPB-Pd_(2)was applied to electrochemical CO_(2)reduction reaction(CO_(2)RR)for the first *** as-obtained BPB-Pd_(2)gives an exceptional Faradaic efficiency of CO(FECO)of 94.4%at−0.80 V *** hydrogen electrode(RHE),which is significantly superior to monoatomic palladium catalyst(BPB-Pd1).The density functional theory(DFT)calculations revealed that the essential reason for the outstanding activity of BPB-Pd_(2)toward CO_(2)RR was that the electronic effect between diatomic palladium reduces the free energy change for CO_(2)RR ***,BPB-Pd_(2)exhibits moderate free energy change to form COOH*intermediate,which was beneficial for the generation of CO in CO_(2)RR.

关键词： synthesis electrocatalysis CO_(2)reduction bimetallic palladium complex synergistic catalysis