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Periodic and chaotic oscillations in mutual-coupled mid-infrared quantum cascade lasers

Chinese Physics B 2022年第10期31卷 352-361页

作者： Zhi-Wei Jia Li Li Yi-Yan Guo An-Bang Wang Hong Han Jin-Chuan Zhang Pu Li Shen-Qiang Zhai Feng-Qi Liu Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi ProvinceCollege of Physics and OptoelectronicsTaiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Semiconductor Materials Science Beijing Key Laboratory of Low Dimensional Semiconductor Materials and DevicesInstitute of SemiconductorsChinese Academy of SciencesBeijing 100083China

Dynamic states in mutual-coupled mid-infrared quantum cascade lasers(QCLs) were numerically investigated in the parameter space of injection strength and detuning frequency based on the Lang-Kobayashi equations model. Three types of period-one states were found, with different periods of injection time delay τ_(inj), 2τ_(inj), and reciprocal of the detuning frequency. Besides, square-wave, quasi-period, pulse-burst and chaotic oscillations were also observed. It is concluded that external-cavity periodic dynamics and optical modes beating are the mainly periodic dynamics. The interaction of the two periodic dynamics and the high-frequency dynamics stimulated by strong injection induces the dynamic states *** work helps to understand the dynamic behaviors in QCLs and shows a new way to mid-infrared wide-band chaotic laser.

关键词： periodic oscillations chaotic oscillations mutual-coupled quantum cascade lasers

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A copula-based reliability model for phased mission systems with dependent components (vol 39, pg 1533, 2023)

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QUALITY AND RELIABILITY ENGINEERING INTERNATIONAL 2023年第7期39卷 3179-3179页

作者： Li, X. Zhan, K. Xiong, X. Vu, T. Q. Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education Taiyuan University of Technology Taiyuan China School of Media Design College of Technology and Design University of Economics Ho Chi Minh City Vietnam

Recently, researches on the reliability analysis of phased mission systems (PMSs) are very popular. And most of the existing research on PMSs assumed that all the components are statistically independent on each other, which is not meet the engineering reality. The system structure changes from phase to phase in the PMSs, so the dependency among components may also change in different phases. Meanwhile, the well-known phase dependency is also existing in the system reliability modeling. To model the varying dependency among components and phase dependency at the same time, a copula-based method is proposed for the reliability analysis of PMS with correlated components. Firstly, the system reliability of multi-state PMS with dependent components is evaluated by different copula functions. Then, multiple indicators are used to select the optimal copula functions for different phases. And an engineering case is illustrated to show the proposed copula-based method.

关键词： copula dependent components modular method phased mission system

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Reflectionless spatial beam benders with arbitrary bending angle by introducing optic-null medium into transformation optics

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Chinese Physics B 2021年第3期30卷 242-247页

作者： Fei Sun Yi-Chao Liu Yi-Biao Yang Hong-Ming Fei Zhi-Hui Chen Sai-Ling He Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi ProvinceCollege of Physics and OptoelectronicsTaiyuan University of TechnologyTaiyuan 030024China National Engineering Research Center for Optical Instruments Center for Optical and Electromagnetic ResearchZhejiang UniversityHangzhou 310058China

By introducing an optic-null medium into the finite embedded transformation,a reflectionless spatial beam bender is designed,which can steer the output beam by a fixed pre-designed angleβfor an arbitrary incident *** bending angleβof the beam bender is determined by the geometrical angle of the device,which can be changed by simply choosing different geometrical *** various bending angles,the designed spatial beam bender can be realized by the same materials(i.e.,an optic-null medium),which is a homogenous anisotropic *** simulations verify the reflectionless bending effect and rotated imaging ability of the proposed beam bender.A reduction model of the optic-null medium is studied,which can also be used for a reflectionless spatial beam bender with a pre-designed bending angle.

关键词： spatial beam benders optic-null medium transformation optics

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Widely tunable chaotic fiber laser for WDM-PON detection

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Optoelectronics Letters 2014年第3期10卷 232-236页

作者：张娟杨玲珍徐乃军王娟芬张朝霞刘香莲 Institute of Optoelectronic Engineering College of Physics and OptoelectronicsTaiyuan University of Technology Key Lab of Advanced Transducers and Intelligent Control System Ministry of EducationTaiyuan University of Technology

A widely tunable high precision chaotic fiber laser is proposed and experimentally demonstrated.A tunable fiber Bragg grating(TFBG) filter is used as a tuning element to determine the turning range from 1533 nm to 1558 nm with a linewidth of 0.5 nm at any *** wide tuning range is capable of supporting 32 wavelength-division multiplexing(WDM) channels with 100 GHz channel *** single wavelengths are found to be chaotic with 10 GHz *** full width at half maximum(FWHM) of the chaotic correlation curve of the different wavelengths is on a picosecond time scale,thereby offering millimeter spatial resolution in WDM detection.

关键词： WDM-PON 光纤激光器可调谐检测光纤布喇格光栅混沌空间分辨率单波长

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The design of multi-parameter online monitoring system of water quality based on GPRS

The design of multi-parameter online monitoring system of wa...

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International Conference on Multimedia Technology

作者： Qiao, Tie-Zhu Song, Le Education Ministry Key Lab of Advanced Transducers and Intelligent Control System Taiyuan Technology University Taiyuan China

ISBN: (纸本)9781424478743

The major method of water quality monitoring was sampling in the scene at present in China. In response to the problems such as weak sampling capability of water quality, untimely data processing and so on, based on GPRS technology, the design scheme of an automatic water quality monitoring system is proposed. The system utilizes the water quality monitor to process the sample and send the relevant data to the monitoring center through the GPRS data transmission. Ultimately, the system realized the function of remote collection, transmission and procession of the water quality parameters. ©2010 IEEE.

关键词： Water quality

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Infrared image detection of belt longitudinal tear based on SVM

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Journal of Computational Information systems 2013年第18期9卷 7469-7475页

作者： Qiao, Tiezhu Zhao, Bilong Shen, Ruiping Zheng, Buxiang State Key Laboratory of Advanced Transducers and Intelligent Control System Taiyuan University of Technology Taiyuan 030024 China Hudi Coal of Jincheng Coal Jincheng 048214 China Xishan Coal and Electricity of Xinjiashe Taiyuan 030200 China

In order to test the fault of belt longitudinal tear efficiently, an infrared image detection method using support vector machine (SVM) is proposed. The infrared images of belt are collected to avoid the adverse effects of the complicated environment of mine. An infrared image segmentation method based on SVM can remedy the defects of the traditional infrared image segmentation algorithm. Computers will test the belt longitudinal tear or predict its tendency by calculating the quantity of torn pixels. The approach has a good practicability. © 2013 Binary Information Press.

关键词： Support vector machines

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Realizing mode conversion and optical diode effect by coupling photonic crystal waveguides with cavity

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Chinese Physics B 2015年第9期24卷 284-288页

作者：叶寒张金倩楠俞重远王东林陈智辉 State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications Theoretical Condensed Matter Physics and Computational Materials Physics Laboratory School of PhysicsUniversity of Chinese Academy of Sciences Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi ProvinceTaiyuan University of Technology

We propose a novel two-dimensional photonic crystal structure consisting of two line defect waveguides and a cavity to realize mode conversion based on the coupling effect. The W1/cavity/W2 structure breaks the spatial symmetry and successfully converts the even（odd） mode to the odd（even） mode in the W2 waveguide during the forward（backward）transmission. When considering the incidence of only the even mode, the optical diode effect emerges and achieves approximate 35 d B unidirectionality at the resonant frequency. Moreover, owing to the narrow bandpass feature and the flexibility of the tuning cavity, utilization of the proposed structure as a wavelength filter is demonstrated in a device with a Y-branch splitter. Here, we provide a heuristic design for a mode converter, optical diode, and wavelength filter derived from the coupling effect between a cavity and adjacent waveguides, and expect that the proposed structure can be applied as a building block in future all-optical integrated circuits.

关键词： mode conversion optical diode photonic crystal

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Performance analysis of several wavelets in pipeline leak detection and location using Colpitts chaotic signal

Performance analysis of several wavelets in pipeline leak de...

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2018 International Conference on Electronics Technology, ICET 2018

作者： Zhang, Zhaoxia Cui, Gongzhe Xue, Xiaozhen Yang, Lingzhen Wang, Juanfen Xue, Pingping College of Physics and Optoelectronics Taiyuan University of Technology Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education Taiyuan Shanxi030024 China

ISBN: (纸本)9781538657522

In this paper, the performance of wavelet transform on the detection and location of pipeline leak are explored. The effects of three wavelets on different thresholds and different decomposition layers are studied. Firstly, the UWB(Ultra Wideband) chaotic signal generated by Colpittscircuit is used as the signal detection signal, and the leak point of the pipeline is detected and located by analyzing the cross-correlation coefficient between the detection signal and the echo signal after the pipeline reflection. Because there are some questions such as how to choose the optimal threshold function, wavelets and optimal number of decomposed layers, three wavelet thresholds (hard threshold, soft threshold and given threshold)which has different signal-To-noise ratio (5dB, 10dB, 30dB) are used in signal threshold denoising. The paper explores the denoising effects of three wavelets(sym4, db4, Haar) after three, four and five wavelet decomposition, and finally gets the optimal threshold method, wavelet function and decomposition layer. This is important to achieve high-precision detection and location of water pipeline leak. © 2018 IEEE.

关键词： Leak detection

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Physics and applications of Raman distributed optical fiber sensing

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Light(Science & Applications) 2022年第6期11卷 1059-1087页

作者： Jian Li Mingjiang Zhang College of Physics and Optoelectronics Taiyuan University of TechnologyTaiyuanShanxi 030024China Key Laboratory of Advanced Transducers and Intelligent Control Systems(Ministry of Education and Shanxi Province) Taiyuan University of TechnologyTaiyuan 030024China

Raman distributed optical fiber sensing has been demonstrated to be a mature and versatile scheme that presents great flexibility and effectivity for the distributed temperature measurement of a wide range of engineering applications over other established *** past decades have witnessed its rapid development and extensive applicability ranging from scientific researches to industrial ***,there are four theoretical or technical bottlenecks in traditional Raman distributed optical fiber sensing:(ⅰ)The difference in the Raman optical attenuation,a low signal-to-noise ratio(SNR)of the system and the fixed error of the Raman demodulation equation restrict the temperature measurement accuracy of the system.{ⅱ)The sensing distance and spatial resolution cannot be reconciled.(ⅲ)There is a contradiction between the SNR and measurement time of the system.(ⅳ)Raman distributed optical fiber sensing cannot perform dual-parameter *** on the above theoretical and technical bottlenecks,advances in performance enhancements and typical applications of Raman distributed optical fiber sensing are reviewed in this *** of this optical system technology with knowledge based,that is,demodulation technology *** further the performance and accuracy of these systems.

关键词： fiber optical contradiction

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Ultra-wide tuning single channel filter based on one-dimensional photonic crystal with an air cavity

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Journal of Semiconductors 2017年第2期38卷 26-30页

作者： Xiaodan Zhao Yibiao Yang Zhihui Chen Yuncai Wang Hongming Fei Xiao Deng Department of Physics and Optoelectronics Taiyuan University of Technology Taiyuan 030024 China Key Laboratory of Advanced Transducers and Intelligent Control System Taiyuan University of TechnologyMinistry of Education Taiyuan 030024 China

By inserting an air cavity into a one-dimensional photonic crystal of LiF/GaSb, a tunable filter covering the whole visible range is proposed. Following consideration of the dispersion of the materials, through modulating the thickness of the air cavity, we demonstrate that a single resonant peak can shift from 416.1 to 667.3 nm in the band gap at normal incidence by means of the transfer matrix method. The research also shows that the transmittance of the channel can be maximized when the number of periodic Li F/Ga Sb layers on one side of the air defect layer is equal to that of the other side. When adding a period to both sides respectively, the full width at half maximum of the defect mode is reduced by one order of magnitude. This structure will provide a promising approach to fabricate practical tunable filters in the visible region with ultra-wide tuning range.

关键词： photonic crystal filters transfer matrix method single resonant peak ultra-wide tuning range mechanical modulation

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