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Fiber laser twist sensor with hybrid few-mode tilted Bragg grating and few-mode long period grating

optoelectronics Letters 2019年第3期15卷 161-164页

作者： YANG Kang LIU Yan-ge WANG Zhi LI Guo-yu HAN Ya ZHANG Hong-wei MAO Bai-wei Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology Institute of Modern OpticsNankai UniversityTianjin300350China Institute of Information Technology Handan UniversityHandan056005China

A twist sensor with hybrid few-mode tilted fiber Bragg grating(FM-TFBG) and few-mode long period grating(FM-LPG) in fiber laser cavity is demonstrated. The FM-LPG is utilized to excite LP11 core mode. The FM-TFBG is used for sensing. The transverse modes at 1 553.9 nm and 1 550.5 nm are LP01 and LP21 core modes, respectively, which are coupled from forward-propagating LP11 core mode. These two excitation wavelengths have opposite variation tendencies, which participate in sensing. The twist sensitivity of 0.16 dB/° from-40° to 40° is achieved. The proposed sensor has potentially used for structure monitoring in many areas.

关键词： LPG Fiber laser twist sensor with hybrid few-mode tilted Bragg grating and few-mode long period grating

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Holographic grating fabrication for wide angular bandwidth using polymer thin films

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optoelectronics Letters 2021年第1期17卷 1-4页

作者： WU Peng-fei WU Zi-jun ZHUANG Yu LIU Hong-liang Institute of Modern Optics Nankai UniversityTianjin 300071China Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology Tianjin 300350China Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology Tianjin 300350China

To increase the angular bandwidth of volume holographic grating, we fabricate holographic gratings based on grating multiplexing technique by using thin films of photopolymers and polymer dispersed liquid crystals. Experimental results confirm that the liquid crystal materials increase the refractive index modulation of the grating, enabling high diffraction efficiency with wide angular response compared to pure polymer materials. We observe that the fabricated holographic grating has near 80% of diffraction efficiency and about 18° of angular bandwidth, which can be further improved by modifying the liquid crystal/polymer mixtures and the grating multiplexing technique. The grating can be used to fabricate holographic waveguide structures for emerging applications in the near-eye display systems.

关键词： technique. waveguide holographic

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High-Sensitivity Fabry-Pérot Strain Senor Based on Fusion Splicing Photonic Crystal Fiber and Single Mode Fiber 11

High-Sensitivity Fabry-Pérot Strain Senor Based on Fusion S...

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11th International Symposium on Communication Systems, networks and Digital Signal Processing, CSNDSP 2018

作者： Liu, Haifeng Liu, Bo Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology Institute of Modern Optics Nankai University 300071 China

ISBN: (纸本)9781538613351

A high-sensitivity strain FPI with a super-short 1.24 μm F-P cavity has been proposed in this paper, the F-P cavity is generated by an optimized fusion splicing of SMF and a section complete collapsed PCF. The experimental results exhibit that the wavelength of reflected interference spectrum is high sensitivity to axis force, and the strain sensitivity is high up to 60.7 pm/μϵ. The proposed strain sensor is anticipated to find potential applications in weak strain field detection, and moreover the immunity to temperature and surrounding refractive index ensures its applicability in temperature-fluctuated environments. © 2018 IEEE.

关键词： Refractive index

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Optical adaptive filtering for Doppler shift simulator

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optoelectronics Letters 2019年第5期15卷 330-334页

作者： HOU Jia-qing YAO Yuan LI Jin-ye LIU Hai-feng LIU Bo LIN Wei ZHANG Hao Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology Institute of Modern Optics Nankai University Tianjin 300350 China The State Key Laboratory of Integrated Optoelectronics Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China

Based on free space laser communication, this article describes the working principle of electro-optical frequency shifting, designs an optical adaptive filtering module, and builds the core module of the dynamic optical Doppler shifting simulator for laser channel. It is expected to be applied to the heaven-ground integrated communication link. In this article, we adopt the electro-optical frequency shifting technique combined with the microwave-light wave. In the 1 550 nm band, the negative feedback algorithm is used to complete the adaptive filtering, which realizes optical Doppler frequency shifting and high-precision locking. The frequency shift range reaches +5.5-+32 GHz, and the analog precision is better than 645 Hz. When the microwave frequency is greater than 13.5 GHz, the signal-to-noise ratio(SNR) of the output optical power reaches 20 d B, which lays the foundation for the next stage space laser communication.

关键词： Optical adaptive filtering Doppler shift simulator signal-to-noise ratio(SNR)

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Fiber-coupler-based microfluidic system for trapping of DNA biomolecules

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optoelectronics Letters 2019年第6期15卷 476-480页

作者： WU Ji-xuan WANG Qian SONG Bin-bin LIU Bo ZHANG Hao ZHANG Cheng DUAN Shao-xiang BAI Hua Tianjin Key Laboratory of Optoelectronic Detection Technology and Systems Tianjin Key Laboratory of Engineering Technologies for Cell Phamaceutica College of Electronic and Information Engineering Tianjin Polytechnic University Key Laboratory of Computer Vision and Systems Ministry of Education School of Computer Science and Engineering Tianjin University of Technology Key Laboratory of Optoelectronic Sensor and Sensing Network Technology College of Electronic Information and Optical Engineering Nankai University

A miniature fiber-coupler-based microfluidic system is proposed for trapping of DNA biomolecules. The loop-shaped fiber-coupler is fabricated by using flame tapering technique and integrated in a microfluidic channel. Probe-DNA immobilized on the fiber-coupler surface enables specific recognition of target DNA sequences and effectively facilitates the trapping of target DNA molecules. The binding characteristics of biomolecules on the fiber-coupler surface have been theoretically analyzed and experimentally demonstrated. Experimental results indicate that the spectral response of the loop-shaped fiber coupler immobilized with probe DNA exhibits a red-shift with the trapping of the DNA biomolecules. The proposed microfluidic system possesses such desirable merits as simple structure, label-free method and high integration, which make it a promising candidate for applications in molecular biology and related bioengineering areas.

关键词： fiber trapping system

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Sidelobe suppression and axial resolution enhancement in 4pi microscopy with higher-order radially polarized Laguerre–Gaussian beams using subtractive imaging

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Chinese Optics Letters 2019年第12期17卷 38-43页

作者： Zhiyuan Gu Xianghui Wang Jianxin Wang Fei Fan Shengjiang Chang Institute of Modern Optics Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network TechnologyNankai UniversityTianjin 300350China

Subtractive imaging is used to suppress the axial sidelobes and improve the axial resolution of 4 pi microscopy with a higher-order radially polarized(RP)Laguerre–Gaussian(LG)beam.A solid-shaped point spread function(PSF)and a doughnut-shaped PSF with a dark spot along the optical axis are generated by tightly focusing a higher-order RP-LG beam and a modulated circularly polarized beam,*** subtracting the two images obtained with those two different PSFs,the axial sidelobes of the subtracted PSF are reduced from 37% to about 10% of the main lobe,and the axial resolution is increased from 0.21λ to 0.15λ.

关键词： polarized axial radial

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Performance of differential phase shift keying maritime laser communication over log-normal distribution turbulence channel

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optoelectronics Letters 2021年第2期17卷 90-95页

作者： QIAO Yuan-zhe LU Ze-hui YAN Bao-luo LI Chang-jin ZHANG Hao LIN Wei LIU Hai-feng LIU Bo Beijing Institute of Remote Sensing Equipment Beijing 100039China Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology Institute of Modern OpticsNankai UniversityTianjin 300350China Southern Marine Science and Engineering Guangdong Laboratory Zhuhai 519000China

Laser communication is essential part of maritime-terrestrial-air intelligent communication/sensor network. Among them, different modulation formats would play a unique role in specific applications. Based on Rytov theory, we discussed system performance of the maritime laser communication with repeated coding technology in several modulation schemes. The closed-form expression of average bit error rate(BER) from weak to moderate atmospheric turbulence described by log-normal distribution is given. Differential phase shift keying(DPSK) modulation, as a potential solution for future maritime laser communication, has attracted a lot of attention. We analyzed the effects of atmospheric turbulence parameters(visibility, refractive index structure coefficient, non-Kolmogorov spectral power-law exponent, turbulence inner scale) and DPSK system parameters(receiver aperture diameter, repeat time) on average BER in detail. Compared with the aperture-averaging effects, the system BER can be well suppressed through increasing repeat time. This work is anticipated to provide a theoretical reference for maritime laser communication systems.

关键词： communication DPSK turbulence

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Terahertz magneto-optical isolator based on graphene-silicon waveguide

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Science China(Information Sciences) 2022年第6期65卷 275-276页

作者： Dan ZHAO Fei FAN Tengfei LI Zhiyu TAN Jierong CHENG Shengjiang CHANG Institute of Modern Optics Nankai University Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology College of Electronic Information and Optical Engineering Nankai University Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology College of Electronic Information and Optical Engineering Nankai University

Dear editor,Optical isolators and circulators are non-reciprocal one-way transmission devices, which only allow light to transmit in one direction and prevent light from transmitting in the opposite direction. Thus, they can protect the light source and detector in the integrated microwave or optical system, and also significantly reduce the additional noises. However, due to the limitation of material and device mechanism,

关键词： graphene magneto-optical device isolator Waveguide Terahertz

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Beidou BlI Signal Acquisition Scheme Based on Variable Length Data Accumulation 9th

Beidou BlI Signal Acquisition Scheme Based on Variable Lengt...

引用

9th China Satellite Navigation Conference, CSNC 2018

作者： Yang, Menghuan Wang, Guoping Zhao, Yingxin Wu, Hong College of Electronic Information and Optical Engineering Nankai University Tianjin China Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology Tianjin China

ISBN: (纸本)9789811300134

The Neumann-Hoffman code is modulated in Beidou D1 navigation message, which increases the possibility of bit sign transition. It puts a constraint on the coherent integration duration for possible bit sign transition. An acquisition scheme of Beidou B1I signal has been proposed in this paper. Firstly, the carrier and sign bit code are deprived by delay and multiplication. Then, the Doppler shift of the ranging code is searched. According to the Doppler shift of ranging code, the variable length of data block is accumulated to 1 ms data. Finally, the ranging code phase is detected by FFT-based synchronized algorithm. The carrier frequency offset, whose boundary is determined by the Doppler shift of ranging code, is accurately estimated by means of chirp-z transform. The experiment shows that the method can achieve long-term coherent integration and improve the acquisition probability. © Springer Nature Singapore Pte Ltd. 2018.

关键词： Doppler effect

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High-precision two-way time transfer system via long-distance commercial fiber link

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optoelectronics Letters 2017年第6期13卷 427-431页

作者：慈骋赵迎新吴虹刘波章学松张瑜 Institute of Electronic Information and Optical Engineering Nankai University Tianjin 300071 China Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology Nankai University Tianjin 300071 China Key Laboratory of Optical Information Science and Technology Ministry of Education Nankai University Tianjin 300071 China

Time synchronization techniques, especially on the pulse per second(PPS) temporal basis, have attracted growing research interests in recent years. In this paper, we have proposed and experimentally demonstrated a high-precision two-way time transfer(TWTT) system to realize long-distance dissemination of 1 PPS signal generated by a hydrogen maser. A dense-wavelength-division-multiplexing(DWDM) system and bi-directional erbium-doped fiber amplifiers(Bi-EDFAs) have also been adopted to suppress the impact of Rayleigh backscattering and optimize the signal to noise ratio(SNR) as well. We have theoretically analyzed the systematic delay in detail. The ultimate root mean square(RMS) variation of time synchronization accuracy is sub-26 ps and the time deviation can be reduced to as low as 1.2 ps at 100 s and 0.253 ps at 12 000 s, respectively.

关键词： dissemination multiplexing directional deviation ultimate Rayleigh dense suppress have instrumental

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