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Multi-wavelength actively Q-switched random fiber laser based on EOM and a real-time configurable filter

Optical and Quantum Electronics 2024年第12期56卷 1-13页

作者： Li, Rupeng Liu, Zhanzhi Pan, Honggang Dai, Hongli Chen, Chunqi Zhao, Zihong Engineering Research Center of Communication Devices and Technology Ministry of Education Tianjin Key Laboratory of Film Electronic and Communication Devices School of Integrated Circuit Science and Engineering Tianjin University of Technology Tianjin300384 China

A multi-wavelength actively Q-switched random fiber laser based on real-time configurable Waveshaper and electro-optic modulator is proposed and experimentally demonstrated. The random feedback of the laser is provided by Rayleigh scattering generated by the single-mode fiber. The Waveshaper not only acts as a multi-channel filter, but also introduces wavelength-dependent losses in the laser cavity, which can suppress the mode competition caused by uniform broadening of the erbium-doped fiber and the power imbalance caused by Rayleigh scattering. Additional dispersion, group delay, phase and other parameters can be introduced through Waveshaper, and then the influence of additional quantities such as dispersion on actively Q-switched random fiber laser is studied. In the experiment, when the additional dispersion changes within -200 ~ 200 ps/nm, the pulse width of actively Q-switched can change between 1.01 ~ 1.18 μs. Compared with other experiments, this experiment further and more accurately studied the effects of dispersion, group delay and phase on actively Q-switched pulses. Because of the half-open cavity and erbium-doped fiber gain, the laser threshold is suppressed to 25 mW. The powers distribution on the wavelengths are uniform, and the amplitude difference between the ten wavelengths is © The Author(s), under exclusive licence to Springer science+Business Media, LLC, part of Springer Nature 2024.

关键词： Group delay

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research on the variation of dielectric properties of oil-paper insulation for power equipment over a wide temperature range

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High Voltage 2024年第3期9卷 648-658页

作者： Mingze Zhang Muhe Yu Wen Zhou Yilin Liang Shengjie Lei Yunbo Shi Limin Qu Key Laboratory of Engineering Dielectrics and Its Application Ministry of Education Harbin University of Science and TechnologyHarbinChina School of Measurement and Communication Engineering Harbin University of Science and TechnologyHarbinChina Electric Power Research Institute State Grid Heilongjiang Electric Power Company LimitedHarbinChina

The main part of oil-immersed power equipment is oil-paper *** lower ambient temperatures,transformer oil will become *** a result,compared to those at room temperature or operating temperature,the frequency domain dielectric properties of oil-paper insulation at low temperatures are drastically *** evaluating the insulation condition of electrical equipment,it is essential to accurately determine their dielectric *** paper described the FDS test,the DC conductivity test,and the transformer oil viscosity test,which was carried out in a laboratory environment for different ageing of oil-immersed pressboard and transformer oil at 233–373 *** ef-fects of temperature on the dielectric properties at the competing mechanisms of polarisation and conductivity loss were clarified based on variations of the FDS *** the viscosity change of ageing transformer oil at low temperatures,the Arrhenius and VFT viscosity equations were used to achieve a fitting calculation in the different temperature *** on the molecular/ion transition model in the force field and electric field,the characterisation relationships between the dynamic viscosity,DC conductivity,and test temperature of transformer oil were *** limita-tions of conventional transformer oil equivalent dielectric relaxation models over a wide temperature range were finally clarified by combining the test findings of the DC con-ductivity over a wide temperature range with observed and simulated *** paper provides an essential theoretical reference when using the FDS test to diagnose the insulation performance of oil-immersed power equipment in extremely cold regions.

关键词： insulation viscosity immersed

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Optimizing satellite image brightness and entropy with the african vulture algorithm for enhanced visual quality

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International Journal of Information technology (Singapore) 2025年 1-12页

作者： Rajesh, V. Sivakumar, P. Department of Electronics and Communication Engineering SRM Institute of Science and Technology Tiruchirappalli Tiruchirappalli India Department of Electronics and Communication Engineering Kalasalingam Academy of Research and Education Tamil Nadu Krishnankoil India

Satellite images commonly exhibit constrained brightness values, facilitating the enhancement of contrast to preserve pertinent details before conducting further image analysis. Enhancing the brightness of the images serves as an first phase in the analysis of image, given that image quality significantly influences human perception. Metaheuristics have proven to be effective in addressing intricate image processing challenges. This paper presents an effort to present the versatility and effectiveness of a method in searching best solutions to enhance the brightness of the images. The image’s intensity is improved through a transformation term (TT) and the AVA (African Vulture Algorithm). The intensity transformation integrates information from optimal information of the satellite images. The AVA method is utilized to determine the optimal pixel values capable of enhancing the maximization in low contrast satellite images. Simultaneously, the AVA considers the objective function which enhances the image quality by considering the factors which includes entropy and edge details. The experimentation is demonstrated on the dataset and achieved better contrast and entropy values of 21.036 and 0.806 respectively. © Bharati Vidyapeeth's Institute of Computer Applications and Management 2025.

关键词： African vulture algorithm Edge details Entropy Optimal solutions Satellite images Transformation term

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Dual-band terahertz antenna based on a novel photonic band gap structure

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Optoelectronics Letters 2023年第11期19卷 666-672页

作者： BAI Yukun LI Jie Tianjin Key Laboratory of Film Electronic and Communication Devices Engineering Research Center of Optoelectronic Devices and Communication TechnologyMinistry of EducationSchool of Integrated Circuit Science and EngineeringTianjin University of TechnologyTianjin300384China

In this paper,a novel dual-band photonic band gap(PBG) structure was proposed and applied to a dual-band micro-strip *** antenna resonates at 1.267 THz and 1.502 THz,exhibiting reflection coefficients of-58.177 dB and-49.462 dB,and gains of 3.173 dBi and 5.232 dBi,*** with the microstrip antenna based on the homogeneous silicon substrate,the designed dual-band antenna based on the novel PBG structure shows improved impedance matching,radiation efficiency,and *** paper simulated and analyzed the impacts of different filling dielectric materials and the variations of dimensions,position,period,and corrugation depths of the dual-band PBG structure on the resonances of the *** is expected that the proposed novel dual-band PBG structure has great application potentials,and such cancer diagnosis is done by utilizing the radiation characteristics of the antenna.

关键词： antenna structure band

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Secure deep learning-based energy efficient routing with intrusion detection system for wireless sensor networks

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Journal of Intelligent and Fuzzy Systems 2024年第4期46卷 8587-8603页

作者： Sakthimohan, M. Deny, J. Elizabeth Rani, G. Department of Electronics and Communication Engineering Kalasalingam Academy of Research and Education Tamil Nadu India Department of Computer Science and Engineering Kalaignar Karunanidhi Institute of Technology Tamil Nadu Coimbatore India

In general, wireless sensor networks are used in various industries, including environmental monitoring, military applications, and queue tracking. To support vital applications, it is crucial to ensure effectiveness and security. To prolong the network lifetime, most current works either introduce energy-preserving and dynamic clustering strategies to maintain the optimal energy level or attempt to address intrusion detection to fix attacks. In addition, some strategies use routing algorithms to secure the network from one or two attacks to meet this requirement, but many fewer solutions can withstand multiple types of attacks. So, this paper proposes a secure deep learning-based energy-efficient routing (SDLEER) mechanism for WSNs that comes with an intrusion detection system for detecting attacks in the network. The proposed system overcomes the existing solutions’ drawbacks by including energy-efficient intrusion detection and prevention mechanisms in a single network. The system transfers the network’s data in an energy-aware manner and detects various kinds of network attacks in WSNs. The proposed system mainly comprises two phases, such as optimal cluster-based energy-aware routing and deep learning-based intrusion detection system. Initially, the cluster of sensor nodes is formed using the density peak k-mean clustering algorithm. After that, the proposed system applies an improved pelican optimization approach to select the cluster heads optimally. The data are transmitted to the base station via the chosen optimal cluster heads. Next, in the attack detection phase, the preprocessing operations, such as missing value imputation and normalization, are done on the gathered dataset. Next, the proposed system applies principal component analysis to reduce the dimensionality of the dataset. Finally, intrusion classification is performed by Smish activation included recurrent neural networks. The proposed system uses the NSL-KDD dataset to train and test it. The

关键词： Intrusion detection

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Two characteristic parameters for the junction temperature of white LED

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Optoelectronics Letters 2023年第5期19卷 257-261页

作者： CUI Xi JING Lei TONG Zhengrong WANG Xue MA Ming PEI Hexiu Engineering Research Center for Optoelectronic Devices and Communication Technology of the Ministry of Education School of Integrated Circuit Science and EngineeringTianjin University of TechnologyTianjin 300384China

This paper proposes a method for characterizing the junction temperature of light-emitting diodes(LEDs)by using two parameters,and the selected reference method is used to eliminate the self-heating effect of white *** constant current source is used to drive,which improves the practicability and reduces the measurement *** junction temperature of cold and warm white LED is measured with a small current of 50—400 mA as the driving *** studied ambient temperature range is 30—80℃.The results show that the relationship between the spectrum valley value of the calibration function,the full width at half maximum(FWHM),driving current,and junction temperature can be combined with a high degree of the *** with the measurement results of the forward voltage method,the maximum error of the measurement of the two-parameter joint characterization junction temperature method is only 2.38℃.It is a low-cost,practical,and effective junction temperature measurement method for white LEDs.

关键词： white parameters driving

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Energy Efficiency Enhancement in LTE-A Network Using SP-ZF with Channel Estimation and Power Allocation Algorithm

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Journal of The Institution of Engineers (India): Series B 2023年第3期104卷 703-713页

作者： Ragunathan, Surender Perumal, Dananjayan Department of Electronics and Communication SRM Institute of Science and Technology Ramapuram Campus Chennai India Department of Electronics and Communication St. Peter’s Institute of Higher Education and Research Chennai India

Fifth-generation wireless networks require energy efficient and seamless connectivity, and it is offered by massive MIMO system using spatial multiplexing with unprecedented array gain. As massive MIMO communication involves antennas in large scale, the network is characterized by interference, caused by pilot contamination and creates limitation in the network capacity. One of the methods to combat the interference instigated by pilot contamination is by using proper channel estimator with precoding schemes. To analyse the long-term evolution-advanced network performance, superimposed pilot in zero forcing precoding scheme with channel elemental-wise minimum mean square estimator has been employed. Further, the energy efficiency of the network is enhanced using iterative energy efficient power allocation algorithm and it is analysed with that of conventional system using minimum mean square estimator. The outcomes of the simulation show that proposed work will perform better than conventional system in terms of sum rate and energy efficiency. © 2023, The Institution of Engineers (India).

关键词： Energy efficiency

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Micro-displacement sensor based on an asymmetric wavy multimode fiber interferometer

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Optoelectronics Letters 2023年第3期19卷 134-138页

作者： LI Yuanzheng LI Yi MIAO Yinping WANG Fang HU Kai ZHANG Kailiang Tianjin Key Laboratory of Film Electronic and Communication Devices School of Integrated Circuit Science and EngineeringEngineering Research Center of Optoelectronic Devices&Communication TechnologyMinistry of EducationTianjin University of TechnologyTianjin 300384China

We proposed a compact and tunable multimode interferometer(MMI)based on an asymmetric wavy fiber(AMWF),which has axial offset,off-center taper waist,and *** fabrication process only contains non-axis pulling processes of single-mode fiber on two close *** qualitative analyses and experiments verify the tunable multimode propagation of the *** results show a nonlinear wavelength response with increasing axis displacement from 0 to 120μ*** the range of 0—10μm,the sensitivity reaches the highest value of-1.33 nm/μ*** to its cost-effective,high-compact and tunable multimode propagation properties,the AMWF provides a promising platform for micro-nano photonic devices and optical sensing applications.

关键词： interferometer fiber multimode

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Temperature-insensitive liquid level sensor based on U-shaped SMF

Temperature-insensitive liquid level sensor based on U-shape...

引用

2024 International Conference on Optoelectronic Materials and Devices, ICOMD 2024

作者： Wang, Muhua Tong, Zhengrong Zhang, Weihua Tianjin Key Laboratory of Thin Film Electronics and Communication Devices Engineering Research Center for Optoelectronic Devices and Communication Technology The Ministry of Education School of Integrated Circuit Science and Engineering Tianjin University of Technology Tianjin300384 China

ISBN: (数字)9781510689046

ISBN: (纸本)9781510689039

In this manuscript, a fiber optic sensor based on a U-shaped single mode fiber (SMF) is proposed for liquid level measurement. The U-shaped structure is fabricated by flame burning method. The U-shaped structure leads to energy leakage into the cladding, resulting in modal interference, and the sensor becomes more sensitive to external changes. The experimental results show that the level sensitivity is as high as 255.86 pm/mm in the range of 0-30 mm. The sensor exhibits temperature insensitivity in the range of 20-70 °C. The sensor avoids the problem of temperature crosstalk and is ideal for liquid level measurement. © 2025 SPIE.

关键词： Single mode fibers

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research on high accuracy classification of temperature signals based on OFDR technology and EfficientNet 4

Research on high accuracy classification of temperature sign...

引用

4th International Conference on Advanced Manufacturing technology and Electronic Information, AMTEI 2024

作者： Shang, Chuanyin Li, Peng Tong, Zhengrong Wang, Hao Li, Sibo Tianjin Key Laboratory of Thin Film Electronics and Communication Devices Engineering Research Center for Optoelectronic Devices and Communication Technology the Ministry of Education School of Integrated Circuit Science and Engineering Tianjin University of Technology Tianjin300384 China

ISBN: (数字)9781510688247

ISBN: (纸本)9781510688230

The development of machine learning is driving revolutionary changes and unprecedented opportunities across various industries. This paper introduces a new temperature monitoring method that combines the efficient deep learning model EfficientNet with Optical Frequency Domain Reflectometry (OFDR). We utilize distributed fiber-optic sensing technology based on OFDR to collect one-dimensional temperature signals under different temperature conditions, which we then transform into a two-dimensional image format suitable for machine learning processing. The dataset is subsequently trained using the EfficientNet deep learning model. The results show that the trained model achieves a high accuracy rate of 97.5% on the test dataset. This research not only demonstrates the feasibility of efficiently and accurately monitoring temperature changes but also provides new solutions and technological pathways for areas such as environmental monitoring, industrial automation, and safety systems. © 2025 SPIE.

关键词： education and training Data modeling Performance modeling Fiber optics sensors Machine learning Matrices Fiber optics Image processing Reliability Signal processing

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