检索结果-南通市图书馆

A novel dual-channel thermo-optic locking method for the whispering gallery mode microresonator

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第5期33卷 438-444页

作者：范文杰刘文耀潘梓文王蓉刘来邢恩博周彦汝唐军刘俊 State key laboratory of Dynamic Measurement Technology North University of ChinaTaiyuan 030051China shanxi Province key laboratory of Quantum Sensing and precision Measurement North University of ChinaTaiyuan 030051China

Mode locking can be effectively achieved by using the thermo-optic effects in the whispering gallery mode(WGM)optical microcavity,without the help of external ***,it has the advantages of small size,low integration costs,and self-locking,which shows great potential for ***,the conventional single-channel microcavity thermal-locking method that relies solely on internal thermal balance will inevitably be disturbed by the external *** limitation affects the locking time and ***,in this paper,we propose a new method for closed-loop thermal locking of a dual-channel *** thermal locking of the signal laser and the thermal regulation of the control laser are carried out respectively by synchronously drawing a dual-path tapered *** theoretical model of the thermal dynamics of the dual-channel microcavity system is established,and the influence of the control-laser power on the thermal locking of the signal laser is *** deviation between the locking voltage of the signal laser and the set point value is used as a closed-loop feedback parameter to achieve long-term and highly stable mode locking of the signal *** results show that in the 2.63 h thermal-locking test,the locking stability is an order of magnitude higher than that of the single tapered *** solution addresses the issue of thermal locking being disrupted by the external environment,and offers new possibilities for important applications such as spectroscopy and micro-optical sensor devices.

关键词： optical microcavity thermo-optic locking thermal nonlinearity effect

Accuracy evaluation for in-situ machining reference points binocular measurement based on credibility probability

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第1期37卷 472-486页

作者： Binchao YU Wei LIU Yanze ZHANG Dazhi MA Zhenyuan JIA Yi YUE Jiabo ZHANG key laboratory for precision and Non-Traditional machining Technology of the Ministry of Education Dalian University of TechnologyDalian 116024China Beijing Spacecrafts China Academy of Space TechnologyBeijing 100081China

Passive binocular measurement systems are being increasingly utilized in the in-situ industries of automobiles,aviation,and aerospace,*** to their excellent qualities of accuracy,efficiency,and cost *** the barrier of evaluating the accuracy of measured objects resulted from the unequal equivalent focal length and quantization of pixels,has limited their further development and application of high requirements for in-situ machining,e.g.,the measurement of machining reference points for the positioning of robotic drilling in aerospace *** this paper,an accuracy evaluation method is proposed to address the ***,the unequal equivalent focal length is considered to improve the accuracy of 3D ***,the credibility probability model is developed to calculate the probability of the observed error in the public view of the binocular measurement system and indicates the direction of ***,the in-situ experiment is carried out to validate the method within the effective public view range of 300 mm×300 *** experiment results show that the RMSs of observed errors are superior to 0.035 mm,and the credibility probabilities are all higher than 0.91;the maximum 3D reconstruction accuracy improvement is 60.3%,with the error reduced from 0.078 mm to 0.031 mm.

关键词： Aerospace manufacturing Binocular vision Credibility probability Pixel quantization Unequal equivalent focal length

Advancing electrochemical drilling process via coupling of flow field and electric field in pulsating state generated by a novel tube tool

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第4期37卷 542-555页

作者： Liang CHENG Xiaolei CHEN Zhisen YE Yongjun ZHANG State key laboratory of precision Electronic Manufacturing Technology and Equipment Guangdong University of TechnologyGuangzhou 510006China Guangdong key laboratory of Advanced Manufacturing Technology of Marine Energy Equipment Guangdong University of TechnologyGuangzhou 510006China Guangzhou key laboratory of Nontraditional machining and Equipment Guangdong University of TechnologyGuangzhou 510006China

This paper introduces an improvement to electrochemical drilling process by coupling flow field and electric field in pulsating state. A novel tube with half-wedged shape at the end(HW-tube) is prepared, with both sidewall and wedged part of the HW-tube insulated. Only the flat part is utilized to provide electric field for electrochemical drilling. By rotating the HW-tube, both flow field and electric field in pulsating state are generated, alternating in different positions within the inter-electrode gap(IEG). The pulsating flow field enhances the mass transfer process, while pulsating electric field disperses material dissolution process and distribution of electrolytic byproducts. Both pulsating fields are coupled at the same frequency, further enhancing the electrochemical drilling process. Simulation results indicate that both flow field and electric field in pulsating state are generated. Compared to the traditional tube, the HW-tube significantly reduces the number of residual particles in IEG, and this number is further reduced by increasing the rotation speed. Experimental results reveal that the surface quality and dimensional uniformity of small hole are improved with HW-tube. With feed rate of 2.22 mm/min, a small hole with diameter of 1.52± 0.017 mm is drilled, resulting in a surface roughness of 0.331 μm.

关键词： Small holes Electrochemical drilling Tools Pulsating flow field Pulsating electric field

Design of a high sensitivity and wide range angular rate sensor based on exceptional surface

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第8期33卷 277-286页

作者：丁鑫圣刘文耀王师贤陶煜周彦汝白禹刘来邢恩博唐军刘俊 State key laboratory of Dynamic Measurement Technology North University of ChinaTaiyuan 030051China shanxi Province key laboratory of Quantum Sensing and precision Measurement North University of ChinaTaiyuan 030051China

It is found that when the parity–time symmetry phenomenon is introduced into the resonant optical gyro system and it works near the exceptional point,the sensitivity can in theory be significantly amplified at low angular ***,in fact,the exceptional point is easily disturbed by external environmental variables,which means that it depends on harsh experimental environment and strong control ability,so it is difficult to move towards practical ***,we propose a new angular rate sensor structure based on exceptional surface,which has the advantages of high sensitivity and high *** system consists of two fiber-optic ring resonators and two optical loop mirrors,and one of the resonators contains a variable ratio coupler and a variable optical *** theoretically analyze the system response,and the effects of phase and coupling ratio on the system ***,compared with the conventional resonant gyro,the sensitivity of this exceptional surface angular rate sensor can be improved by about 300 times at low *** addition,by changing the loss coefficient in the ring resonator,we can achieve a wide range of 600 rad/*** scheme provides a new approach for the development of ultra-high sensitivity and wide range angular rate sensors in the future.

关键词： exceptional surface exceptional points ring resonator angular rate sensing rotational direction recognition wide operating range

同方期刊数据库

Coherent link between a Ti:sapphire comb and a 1.5μm laser via nonlinear interaction in photonic crystal fiber

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2024年第2期12卷 350-355页

作者： YUAN YAO HAOSEN SHI GUANG YANG BO LI CONGYU WANG HONGFU YU LONGSHENG MA YANYI JIANG State key laboratory of precision Spectroscopy East China Normal UniversityShanghai 200062China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

Optical clock networks have distinct advantages for the dissemination of time/frequency,geodesy,and fundamental *** realize such a network,the telecom band and optical atomic clocks have to be coherently *** the telecom band and optical atomic clocks reside in a distinct spectral region,second-harmonic generation is usually introduced to bridge the large frequency *** this paper,we introduce a new method to coherently link a 1550 nm continuous wave laser with a Ti:sapphire mode-locked laser-based optical frequency *** coupling the 1550 nm continuous wave laser light and the Ti:sapphire comb light together into a photonic crystal fiber,nonlinear interaction takes place,and new comblike frequency components related to the 1550 nm laser frequency are generated in the visible ***,we can detect beat notes between two combs in the visible region with a signal-to-noise ratio of more than 40 dB in a resolution bandwidth of300 *** this signal,we realize an optical frequency divider for converting the frequency of optical clocks in the visible region to the telecom band at 1.55μ*** out-of-loop measurement shows that the additional noise and uncertainty induced in optical frequency conversion are 5×10^(-18)at 1 s averaging time and 2.2×10^(-19),respectively,which are limited by the uncompensated light path fluctuation but fulfill precision measurement using state-of-the-art optical clocks.

关键词： fiber interaction nonlinear

Manipulating the electron dynamics in the non-sequential double ionization process of Ar atoms by an orthogonal two-color laser field

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第6期33卷 338-345页

作者：王鹏昭钱丽洁孙真荣杨岩 State key laboratory of precision Spectroscopy East China Normal UniversityShanghai 200241China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

Electron dynamics during non-sequential double ionization(NSDI) is one of the most attractive areas of research in the field of laser–atom or laser–molecule interaction. Based on the classic two-dimensional model, we study the process of NSDI of argon atoms driven by a few-cycle orthogonal two-color laser field composed of 800 nm and 400 nm laser pulses. By changing the relative phase of the two laser pulses, a localized enhancement of NSDI yield is observed at 0.5πand 1.5π, which could be attributed to a rapid and substantial increase in the number of electrons returning to the parent ion within extremely short time intervals at these specific phases. Through the analysis of the electron–electron momentum correlations within different time windows of NSDI events and the angular distributions of emitted electrons in different channels, we observe a more pronounced electron–electron correlation phenomenon in the recollision-induced ionization(RII) channel. This is attributed to the shorter delay time in the RII channel.

关键词： non-sequential double ionization electron dynamics few-cycle orthogonal two-color laser field

Wearable Leg Movement Monitoring System for High-precision Real-Time Metabolic Energy Estimation and Motion Recognition

在线全文

学校读者我要写书评

暂无评论

Research 2024年第2期2023卷 417-429页

作者： Jinfeng Yuan Yuzhong Zhang Shiqiang Liu Rong Zhu State key laboratory of precision Measurement Technology and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084China

Comprehensive and quantitative assessment of human physical activity in daily life is valuable for healthcare,especially for those who suffer from obesity and neurological disorders or are at high risk of *** wearable devices,e.g.,smartwatches,are insufficient and inaccurate for monitoring highly dynamic limb movements and assessing human ***,we report a new wearable leg movement monitoring system incorporating a custom-made motion sensor with machine learning algorithm to perceive human motion accurately and comprehensively during diverse walking and running *** system enables real-time multimodal perceptions of personal identity,motion state,locomotion speed,and energy expenditure for wearers.A general law of extracting real-time metabolic energy from leg movements is verified although individual gaits show *** addition,we propose a novel sensing configuration combining unilateral lower leg movement velocity with its angular rate to achieve high accuracy and good generalizability while simplifying the wearable *** performances in personal identification(accuracy of 98.7%)and motion-state recognition(accuracy of 93.7%)are *** wearable system also exhibites high-precision real-time estimations of locomotion speed(error of 3.04%to 9.68%)and metabolic energy(error of 4.18%to 14.71%)for new subjects across various time-varying *** wearable system allows reliable leg movement monitoring and quantitative assessment of bodily kinematic and kinetic behaviors during daily activities,as well as safe identity authentication by gait parameters,which would greatly facilitate smart life,personal healthcare,and rehabilitation training.

关键词： smart enable monitoring

Electrostatic generator enhancements for powering IoT nodes via efficient energy management

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2024年第2期10卷 143-152页

作者： Zibo Wu Zeyuan Cao Junchi Teng Rong Ding Jiani Xu Xiongying Ye State key laboratory of precision Measurement Technology and Instruments Department of Precision InstrumentTsinghua University100084BeijingChina

Electrostatic generators show great potential for powering widely distributed electronic devices in Internet of Things(IoT)***,a critical issue limiting such generators is their high impedance mismatch when coupled to electronics,which results in very low energy utilization ***,we present a high-performance energy management unit(EMU)based on a spark-switch tube and a buck converter with an RF *** optimizing the elements and parameters of the EMU,a maximum direct current output power of 79.2 mW m^(-2)rps^(-1)was reached for a rotary electret generator with the EMU,achieving 1.2 times greater power output than without the ***,the maximum power of the contact-separated triboelectric nanogenerator with an EMU is 1.5 times that without the *** excellent performance is attributed to the various optimizations,including utilizing an ultralow-loss spark-switch tube with a proper breakdown voltage,adding a matched input capacitor to enhance available charge,and incorporating an RF inductor to facilitate the high-speed energy transfer *** on this extremely efficient EMU,a compact self-powered wireless temperature sensor node was demonstrated to acquire and transmit data every 3.5 s under a slight wind speed of 0.5 m/*** work greatly promotes the utilization of electrostatic nanogenerators in practical applications,particularly in IoT nodes.

关键词： IoT power generator

Metasurface array for single-shot spectroscopic ellipsometry

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第5期13卷 835-842页

作者： Shun Wen Xinyuan Xue Shuai Wang Yibo Ni Liqun Sun Yuanmu Yang Department of precision Instrument State Key Laboratory of Precision Measurement Technology and InstrumentsTsinghua UniversityBeijing 100084China

Spectroscopic ellipsometry is a potent method that is widely adopted for the measurement of thin film thickness and refractive *** conventional ellipsometers utilize mechanically rotating polarizers and grating-based spectrometers for spectropolarimetric ***,we demonstrated a compact metasurface array-based spectroscopic ellipsometry system that allows single-shot spectropolarimetric detection and accurate determination of thin film properties without any mechanical *** silicon-based metasurface array with a highly anisotropic and diverse spectral response is combined with iterative optimization to reconstruct the full Stokes polarization spectrum of the light reflected by the thin film with high ***,the film thickness and refractive index can be determined by fitting the measurement results to a proper material model with high *** approach opens up a new pathway towards a compact and robust spectroscopic ellipsometry system for the high throughput measurement of thin film properties.

关键词： properties. spectroscopic film