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Six million Q factor micro fused silica shell resonator with teeth-like tines released by femtosecond laser-assisted chemical etching

2009中国控制与决策会议

作者： Wu Chunli~1,Bai Zhiming~2,Xiao Jingkui~3,Wang Jinxing~2 1.School of Information Science & Engineering,Northeastern University,Shenyang 110004,China 2.School of Sciences,Northeastern University,Shenyang 110004,China 3.School of Sciences,Shenyang University,Shenyang 110016,China

Radio frequency(RF) receiving coil is an important element for the signal collection for magnetic resonance imaging(MRI) *** factor(Q) of the RF receiving coil is a crucial parameter impacting the signal-to-noise ratio(SNR) and imaging quality of an MRI *** quality factor Q value of conventional copper receiving coil has achieved a *** superconducting material as the resonance loop of receiving coil can decrease the equivalent resistance and enhance the quality *** this study,high frequency electromagnetism simulation software Ansoft HFSS was adopted to investigate the Q value of the RF receiving *** to the experiment dimension of the Bi2223 and MgB superconducting receiving coil,the simulation models were established,the frequency characteristic curves of the resonance loop were simulated and compared with the the same size copper *** study indicates that using superconducting material as RF receiving coil can efficiently enhance the quality factor for a low field MRI system, thus improve the SNR and imaging quality of an MRI *** research results are significant to the application of the high temperature superconductor in modern medical field.

关键词： Magnetic Resonance Imaging(MRI) RF Receiving Coil Superconducting material quality factor Resonance Loop

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Science China(Technological Sciences) 2024年第6期67卷 1923-1932页

作者： ZHAO Tao SHI Yan LU Kun XI Xiang WU XueZhong XIAO DingBang College of Intelligence Science and Engineering National University of Defense TechnologyChangsha410073China

The quality factor(Q factor)is a crucial performance parameter for *** this paper,a novel release method for highquality micro fused silica shell resonators with teeth-like tines with good surface morphology is *** method is based on femtosecond laser-assisted chemical ***,the optimal energy range of femtosecond laser modification is obtained through mechanism ***,the optimal parameters for a straight line and arc pattern are determined by optimizing the average output power,processing speed,and processing *** results demonstrate why edge breakage in rounded corners is easy under different ***,according to these conclusions,the processing is performed on a micro fused silica shell resonator with a Q factor exceeding 6 *** addition,subsurface damage is rare throughout the fabrication process,and the surface roughness of the released cross section reaches the nanometer *** improved Q factor helps suppress mechanical thermal noise and reduce zero bias and zero bias drift,constituting the primary method for enhancing the performance of the resonant gyroscope.

关键词： micro hemispherical resonator fused silica laser-assisted chemical etching quality factor

A mechanically coupled MEMS filter with high-Q width extensional mode resonators

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Journal of Semiconductors 2024年第8期45卷 41-48页

作者： Wei Wang Wenli Liu Junyuan Zhao Bo Niu Zeyu Wu Yinfang Zhu Jinling Yang Fuhua Yang Institute of Semiconductors Chinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

This work presents a novel radio frequency(RF)narrowband Si micro-electro-mechanical systems(MEMS)filter based on capacitively transduced slotted width extensional mode(WEM)*** flexibility of the plate leads to multiple modes near the target *** high Q-factor resonators of around 100000 enable narrow bandwidth filters with small size and simplified *** 1-wavelength and 2-wavelength WEMs were first developed as a pair of coupled modes to form a *** reduce bandwidth,two plates are coupled with aλ-length coupling *** 79.69 MHz coupled plate filter(CPF)achieved a narrow bandwidth of 8.8 kHz,corresponding to a tiny 0.011%.The CPF exhibits an impressive 34.84 dB stopband rejection and 7.82 dB insertion loss with near-zero passband *** summary,the RF MEMS filter presented in this work shows promising potential for application in RF transceiver front-ends.

关键词： MEMS narrowband filter mechanically coupling quality factor width extensional mode

Investigation on photonic crystal nanobeam cavity based on mixed diamond–circular holes

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Nanotechnology and Precision Engineering 2024年第1期7卷 63-70页

作者： Jingtong Bin Kerui Feng Shang Ma Ke Liu Yong Cheng Jing Chen Qifa Liu College of Telecommunication and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing 210003China College of Electronic and Optical Engineering and College of Flexible Electronics(Future Technology) Nanjing University of Posts and TelecommunicationsNanjing 210003China State Key Laboratory of Advanced Optical Communication Systems and Networks Shanghai Jiao Tong UniversityShanghai 200240China

A photonic crystal nanobeam cavity(M-PCNC)with a structure incorporating a mixture of diamond-shaped and circular air holes is *** performance of the cavity is simulated and studied *** theﬁnite-difference time-domain method,the parameters of the M-PCNC,including cavity thickness and width,lattice constant,and radii and numbers of holes,are optimized,with the quality factor Q and mode volume Vm as performance *** modulation of the lattice constant and hole radius enable the proposed M-PCNC to realize outstanding *** optimized cavity possesses a high quality factor Q 1.45105 and an ultra-small mode=×volume Vm 0.01(λ/n)[Zeng et al.,Opt Lett 2023:48;3981–3984]in the telecommunications wavelength *** can be progres-=sively squeezed in both the propagation direction and the perpendicular in-plane direction by a series of interlocked anti-slots and slots in the diamond-shaped hole ***,the energy can be conﬁned within a small mode volume to achieve an ultra-high Q/Vm ratio.

关键词： Photonic crystal nanobeam cavity Mixed diamond–circular holes Slots and anti-slots FDTD simulation quality factor Mode volume

Comparison of Mode quality factors for Equilateral Triangular, Square and Rhombus Optical Micro-Resonators

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Journal of Semiconductors 2001年第2期22卷 117-120页

作者：黄永箴国伟华中国科学院半导体研究所集成光电子国家重点实验室北京100083

The mode frequencies and the quality factors for the equilateral triangular resonator (ETR), the square resonator (SR) and the rhombus resonator (RR) are numerically calculated by the finite difference time domain technique and the Padé approximation. The numerical results show that the resonant modes confined in an equilateral triangular cavity have much higher quality factors than those in the square or the rhombus cavities. The modes in the ETR are totally confined in transverse direction while those in the SR and RR are only partly confined. For the ETR with the side length of 4μm and the refractive index of 3 2, the mode quality factor of about 5 5×10 3 at the wavelength of 1 55μm has been obtained.

关键词： microresonator quality factor resonant frequency finite difference time domain technique semiconductor laser

Bulk GaN-based SAW resonators with high quality factors for wireless temperature sensor

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Journal of Semiconductors 2022年第11期43卷 78-83页

作者： Hongrui Lv Xianglong Shi Yujie Ai Zhe Liu Defeng Lin Lifang Jia Zhe Cheng Jie Yang Yun Zhang Institute of Semiconductors Chinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Beijing Aerospace Micro-electronics Technology Co. Beijing 100854China Lishui Zhongke Semiconductor Material Co. Ltd.Lishui 323000China

Surface acoustic wave(SAW)resonator with outstanding quality factors of 4829/6775 at the resonant/anti-resonant frequencies has been demonstrated on C-doped semi-insulating bulk *** impact of device parameters including aspect ratio of length to width of resonators,number of interdigital transducers,and acoustic propagation direction on resonator performance have been *** the first time,we demonstrate wireless temperature sensing from 21.6 to 120℃ with a stable temperature coefficient of frequency of–24.3 ppm/℃ on bulk GaN-based SAW resonators.

关键词： surface acoustic wave resonator gallium nitride quality factor temperature sensor

Boosting thermoelectrics by alloying Cu_(2)Se in SnTe-CdTe compounds

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Journal of Materials Science & Technology 2021年第30期89卷 45-51页

作者： Zhiyu Chen Juan Li Jing Tang Fujie Zhang Yan Zhong Hangtian Liu Ran Ang Key Laboratory of Radiation Physics and Technology Ministry of EducationInstitute of Nuclear Science and TechnologySichuan UniversityChengdu610064China Interdisciplinary Materials Research Center School of Materials Science and EngineeringTongji UniversityShanghai201804China Institute of New Energy and Low-Carbon Technology Sichuan UniversityChengdu610065Chin

The discovery of band convergence has opened an effective avenue for significantly enhancing thermoelectric performance of SnTe,while alloying CdTe in SnTe is evidenced efficient for improving the valley ***,the thermoelectric transport properties are limited due to the low solubility of CdTe in SnTe(~3%).Inspired by the improvement of dimensionless figure of merit zT in Cu or Se-doped SnTe,investigating the effect of Cu_(2)Se on the electronic and phonon transport properties of SnTe-CdTe alloys is highly ***,improving the quality factor can trigger an increase of the potential of a compound for higher zT,which is of importance for design of thermoelectric ***,alloyed 3%Cu_(2)Se in SnTe-3%CdTe system enables an increased peak zT,which is attributed by the optimization of electronic performance(~21μW cm^(-1)K^(-2)at 800 K),as well as the decreased lattice thermal conductivity owing to the enhanced mass and strain *** importantly,alloying Cu_(2)Se not only improves the quality factor from~0.25 to~0.45,resulting in a higher maximum potential zT,but also effectively preserves the Fermi energy in a relative optimized *** current findings demonstrate the role of Cu_(2)Se for manipulating thermoelectrics in SnTe.

关键词： SnTe Thermoelectrics quality factor Fermi level

Nitrogen doping/infusion of 650 MHz cavities for CEPC

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Nuclear Science and Techniques 2021年第5期32卷 17-23页

作者： Peng Sha Jian-Kui Hao Wei-Min Pan Lin Lin Hong-Juan Zheng Xin-Ying Zhang Fang Wang Ji-Yuan Zhai Zheng-Hui Mi Fei-Si He Shu Chen Bai-Qi Liu Zhi-Tao Yang Chao Dong Zhong-Quan Li State Key Laboratory of Nuclear Physics and Technology&Institute of Heavy Ion Physics Peking UniversityBeijing 100871China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Key Laboratory of Particle Acceleration Physics and Technology Chinese Academy of SciencesBeijing 100049China Center for Superconducting RF and Cryogenics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China

The nitrogen doping/infusion of 650 MHz cavities for the circular electron positron collider(CEPC)is investigated in this *** 650 MHz 1-cell cavities are first treated via buffered chemical polishing(BCP),followed by nitrogen doping.A"2/6"condition is adopted,similar to that for 1.3 GHz cavities of Linear Coherent Light Source *** quality factor of both cavities improved to 7×10^(10)in low fields,i.e.,higher than that obtained from the baseline *** 650 MHz two-cell cavity is nitrogen infused at 165℃for 48 h with a BCP surface *** intrinsic quality factor(Q0)reached6×10^(10)at 22 MV/m in the vertical test,and the maximum gradient is 25 MV/m,which exceeds the specification of the CEPC(4×10^(10)at 22 MV/m).

关键词： Superconducting radio frequency cavity Nitrogen doping Nitrogen infusion quality factor Accelerating gradient

Microwave interrogation cavity for the rubidium space cold atom clock

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Chinese Physics B 2016年第6期25卷 137-143页

作者：任伟高源慈李唐吕德胜刘亮 Key Laboratory of Quantum Optics and Center of Cold Atom Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences School of Electronic Engineering University of Electronic Science and Technology of China

The performance of space cold atom clocks（SCACs） should be improved thanks to the microgravity environment in *** microwave interrogation cavity is a key element in a *** this paper,we develop a microwave interrogation cavity especially for the rubidium *** interrogation cavity has two microwave interaction zones with a single feedin source,which is located at the center of the cavity for symmetric coupling excitation and to ensure that the two interaction zones are in *** interrogation cavity has a measured resonance frequency of 6.835056471 GHz with a loaded quality factor of nearly 4200,which shows good agreement with simulation *** measure the Rabi frequency of the clock transition of the rubidium atom in each microwave interaction zone,and subsequently demonstrate that the distributions of the magnetic field in the two interaction zones are the same and meet all requirements of the rubidium SCAC.

关键词： interrogation cavity microwave interaction phase quality factor