Optical Fiber Technology最新文献

{"title":"Online monitoring of fatigue crack under variable amplitude loading driven by multispectral features fusion of FBG sensors","authors":"Yan Zhao ,&nbsp;Jianxun Gao ,&nbsp;Dianyin Hu ,&nbsp;Zhimin Jiang ,&nbsp;Xuemin Wang ,&nbsp;Jinchao Pan ,&nbsp;Rongqiao Wang","doi":"10.1016/j.yofte.2024.104121","DOIUrl":"10.1016/j.yofte.2024.104121","url":null,"abstract":"<div><div>This paper proposed an online fatigue crack propagation quantitative monitoring method based on fiber Bragg grating (FBG) sensors by introducing the multispectral features fusion and convolutional neural network (CNN) approach. Fatigue crack propagation under variable amplitude loading is simulated by ABAQUS- FRANC3D co-simulation to obtain FBG sensed strain information. FBG distortion spectra were reconstructed using the transfer matrix method (TMM), and the relationship between five damage indicators and fatigue crack, such as center wavelength, spectral area, full width at quarter maximum (FWQM), fractal dimension, and overlapping area, was investigated. Based on this, the FBG spectrum damage feature matrix was constructed to perform multispectral feature fusion. A quantitative monitoring model between damage features and crack length was developed using CNN method to realize real-time monitoring of fatigue crack length, and crack length simulation analysis and fatigue crack propagation test were carried out on aluminum alloy. The results show that the monitoring average absolute error of fatigue crack length is 0.067 mm by proposed method in simulation analysis, and the monitoring average absolute error of fatigue crack length is 0.52 mm in fatigue crack propagation experiment, which verifies the accuracy and effectiveness of this method.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104121"},"PeriodicalIF":2.6,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DRL-based fragmentation- and impairment-aware resource allocation algorithm in C + L band elastic optical networks","authors":"Dan Yan ,&nbsp;Nan Feng ,&nbsp;Jingjing Lv ,&nbsp;Danping Ren ,&nbsp;Jinhua Hu ,&nbsp;Jijun Zhao","doi":"10.1016/j.yofte.2025.104133","DOIUrl":"10.1016/j.yofte.2025.104133","url":null,"abstract":"<div><div>Efficient resource allocation and management can maximize the utilization of spectrum resources in C + L band elastic optical networks (EONs). To minimize spectrum fragmentation after resource allocation, it is vital to carefully design routing, band, modulation, and spectrum allocation (RBMSA) algorithms. However, the relentless pursuit of spectrum efficiency can degrade transmission quality, particularly due to inter-channel stimulated Raman scattering effects that exacerbate physical-layer impairment in C + L band EONs. To address this issue, we categorize lightpaths based on their generalized signal-to-noise ratio (GSNR) and propose a fragmentation- and impairment-aware RBMSA algorithm. Considering the dynamic arrival and release of requests that continuously alter the spectrum state of the network, we employ deep reinforcement learning (DRL) for adaptive resource allocation, state sensing and decision-making. Simulation results demonstrate that the proposed algorithm improves the GSNR of lightpaths and effectively reduces network blocking probability compared to traditional heuristic algorithms and DRL algorithms with simpler reward settings.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104133"},"PeriodicalIF":2.6,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A data augmentation approach combining time series reconstruction and VAEGAN for improved event recognition in Φ-OTDR","authors":"Yi Shi ,&nbsp;Xuwei Kang ,&nbsp;Zhixiang Wei ,&nbsp;Qiren Yan ,&nbsp;Zichong Lin ,&nbsp;Zhenyong Yu ,&nbsp;Yousu Yao ,&nbsp;Zili Dong ,&nbsp;Chuliang Wei","doi":"10.1016/j.yofte.2025.104135","DOIUrl":"10.1016/j.yofte.2025.104135","url":null,"abstract":"<div><div>This paper introduces a data augmentation method based on Time Series Reconstruction (TSR) and Variational Auto-encoder Generative Adversarial Network (VAEGAN) to address the problem of low event recognition accuracy in Φ-OTDR systems caused by scarce samples. TSR method generates new feature data by performing a temporal domain transformation on the Mel spectrograms and the VAEGAN network is utilized to augment the background information. The TSR&amp;VAEGAN can greatly improve the data diversity while keep the feature authenticity. Experiment results show that the proposed approach can improve the classification accuracy of minor class from 88% to 94% when only 10 real minor samples are applied. This method can effectively enhance the event recognition capability of Φ-OTDR systems in scenarios with limited samples.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104135"},"PeriodicalIF":2.6,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical analysis and optimization of high power single frequency co-doped erbium–ytterbium fiber amplifier","authors":"Ahlem Guesmi ,&nbsp;Mohamed Koubàa ,&nbsp;Abdullah S. Karar ,&nbsp;Raymond Ghandour ,&nbsp;Bilel Neji ,&nbsp;Kaboko Jean-Jacques Monga ,&nbsp;Hafedh Mahmoud Zayani ,&nbsp;Chaouki Guesmi ,&nbsp;Mohamed Salhi ,&nbsp;Faouzi Bahloul","doi":"10.1016/j.yofte.2024.104120","DOIUrl":"10.1016/j.yofte.2024.104120","url":null,"abstract":"<div><div>This study presents a comprehensive numerical analysis of a high-power, fully monolithic, single-frequency Erbium–Ytterbium (Er-Yb) fiber amplifier tailored for free-space optical (FSO) applications. Focusing on Erbium Doped Fiber Amplification (EDFA), the investigation aims to understand its behavior and optimize key parameters for enhancing the amplification process. The proposed design consists of four all-fiber master oscillator power amplifier (MOPA) stages, achieving over 20 W of output power at 1550 nm. Specific fiber parameters—such as fiber length, EDF pump power, and signal power—were found to be critical for significantly enhancing EDFA gain. By carefully optimizing these parameters, the performance and efficiency of the amplifier were greatly improved. The four-stage MOPA architecture effectively increases the Brillouin threshold power, allowing for higher output power levels while maintaining single mode performance. Each amplification stage was meticulously designed, with the first stage achieving 280 mW output using a <span><math><mrow><mn>5</mn><mo>.</mo><mn>5</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> core diameter fiber and 800 mW pump power, the second stage producing 1.55 W output with a <span><math><mrow><mn>10</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> core diameter fiber and 10 W pump power, the third stage reaching nearly 5 W output using a <span><math><mrow><mn>12</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> core diameter fiber and 20 W pump power, and the final stage delivering 20 W output with a <span><math><mrow><mn>16</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> core diameter fiber and 70 W pump power.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104120"},"PeriodicalIF":2.6,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physical layer encryption based on digital chaos in THz wireless communication","authors":"Qinghui Chen ,&nbsp;Cong Peng ,&nbsp;Li Zhao ,&nbsp;Weihao You ,&nbsp;Hong Wen ,&nbsp;Jianshe Li","doi":"10.1016/j.yofte.2024.104118","DOIUrl":"10.1016/j.yofte.2024.104118","url":null,"abstract":"<div><div>In this paper, we propose and implement a digital chaos-based encryption scheme that enhances the security of free space communication in a photonics-assisted terahertz wave (THz-wave) wireless data transmission system operating at 340 GHz. We experimentally demonstrate that the delivery of traditional and encrypted 16 Gbaud 16QAM-OFDM and PS-64QAM-OFDM (5.5 bit/symbol) signals over 20 km of standard single mode fiber (SSMF) and a wireless distance 25/54 m. The bit-error ratio (BER) performance of each signal meets the soft-decision forward-error-correction (SD-FEC) threshold of 4.2 × 10⁻². The experimental results show that the encryption scheme does not degrade the performance of the OFDM signals. Furthermore, we analyze the encryption algorithm’s security based on Kerckhoff’s principle, which states that a tiny deviation from the correct keys would make the eavesdropper unable to obtain useful information, and the BER would remain around 0.5. The proposed encryption scheme based on a digital three-dimensional multi-scroll chaotic system, has a huge key space of size 2¹⁴⁵ bits, which can effectively prevent exhaustive key-search attacks.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104118"},"PeriodicalIF":2.6,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A fiber optic sensing intrusion detection method based on WPD-EMD and improved ResNet","authors":"Xinmin Hu ,&nbsp;Xinrui Bai ,&nbsp;Jingqi Li ,&nbsp;Yiting He ,&nbsp;Yingying Li ,&nbsp;Liang Li ,&nbsp;Han Xiao ,&nbsp;Cong Liu ,&nbsp;Fan Zhang ,&nbsp;Jing Tang ,&nbsp;Sheng Hu","doi":"10.1016/j.yofte.2024.104125","DOIUrl":"10.1016/j.yofte.2024.104125","url":null,"abstract":"<div><div>Perimeter security systems are essential for safeguarding critical locations from unauthorized intrusions and various security threats. Traditional video surveillance has limitations like coverage gaps, blind spots, and the need for extensive manual analysis. In contrast, fiber optic systems use distributed sensing technology for real-time, precise data acquisition and automatic anomaly detection, reducing the need for manual monitoring. The Phase-Sensitive Optical Time-Domain Reflectometer (Φ-OTDR) is noted for its high sensitivity, large dynamic range, and robust interference resistance, making it ideal for extensive real-time monitoring. To enhance recognition accuracy, especially for high-threat events requiring zero false alarms, this study proposes a fiber optic sensing signal recognition method using Wavelet Packet Decomposition (WPD) combined with Empirical Mode Decomposition (EMD) and an improved ResNet architecture. Encoding one-dimensional signals into images using Recurrence Plots (RP) leverages advanced techniques from image processing and computer vision, enhancing signal recognition accuracy and application scope. Experimental results show that the WPD-EMD denoising method significantly improves the quality of the original signals, achieving an overall recognition rate of 93.83% for eight types of intrusion signals. For the most representative events (background noise, excavator digging, truck passing, stone knocking), the recognition rate reaches 99.69%. This method shows significant potential for advancing perimeter security monitoring.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104125"},"PeriodicalIF":2.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inter/Intra-ODN capable TWDM PON architecture for efficient OLT resources sharing over different optical networks","authors":"Durgesh Kumar ,&nbsp;Piyush Agrawal ,&nbsp;Vikas Mittal ,&nbsp;Kuldeep Soni ,&nbsp;Amit Kumar Garg ,&nbsp;Vijay Janyani ,&nbsp;Moustafa H. Aly","doi":"10.1016/j.yofte.2024.104116","DOIUrl":"10.1016/j.yofte.2024.104116","url":null,"abstract":"<div><div>The growing multimedia, bandwidth-hungry applications, and real-time services drive tremendous expansion in the communication industry and force service providers to look for more effective ways to provide reliable, energy-efficient, cost-efficient, high-speed, and low-latency data transmission. In this paper, the authors proposed a new energy-efficient and flexible architecture such as a Time and Wavelength Division Multiplexed Passive Optical Network (TWDM-PON) that can enable an Optical Line Terminal (OLT) network sharing of available resources. The proposed architecture can broadcast and/or transmit Point-to-Point (P2P) data for downstream (DS) transmission. The architecture offers low latency direct and dedicated Optical Network Unit (ONU) connections and exhibits the inter-ONU transmission that permits data exchange between two ONUs housed within an Optical Distribution Network (intra-ODN-inter-ONU). The proposed architecture can also send the inter-ONU signals between the ONUs located over different ODNs (inter-ODN-inter-ONU) in the same Optical Private Network (OPN). By implementing the intra-ODN-inter-ONU and inter-ODN-inter-ONU transmissions, the proposed architecture can enhance security and reduce the transmission latency significantly. To the extent of the author’s information, dedicated inter-ODN-inter-ONU transmission has not been addressed in any of the literature till date.</div><div>The proposed architecture also supports, dedicated inter-ODN broadcasting within an OPN for transmitting the same data among multiple ONUs and utilizing the OLT resources optimally. Due to the dynamic recourse allocation at OLT, the proposed architecture provides up to 3-X service reliability and can operate on as minimum as one-third of network resources during low traffic load conditions. Furthermore, through the simulation of the proposed architecture, the Bit Error Rate (BER) performance is in the range of 10^-9 to 10^-12, under various inter-ONU connections. The proposed architecture also reduces upto maximum of 75% of the energy consumption. The proposed architecture would be suitable for enabling a variety of high-speed, real-time internet-based<!--> <!-->applications for mixed-use building customers and smart communities.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104116"},"PeriodicalIF":2.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A highly sensitive refractive index sensor based on super-structured long-period fiber grating","authors":"Qianfei Zhu ,&nbsp;Tian Tian ,&nbsp;Yiwei Ma ,&nbsp;Yongtian Zhu ,&nbsp;Tao Geng ,&nbsp;Libo Yuan","doi":"10.1016/j.yofte.2024.104123","DOIUrl":"10.1016/j.yofte.2024.104123","url":null,"abstract":"<div><div>Fiber refractive index (RI) sensor shows superiority in various applications including biomedical detection and food chemistry. Herein, we propose and investigate a super-structured long-period fiber grating (SLPFG) for RI measurement with the high-sensitivity. This fiber structure is composed of periodically spliced no-core fibers (NCF) and single-mode fiber (SMF) according to a certain modulation function, which effectively excites the high order cladding mode and improves the sensitivity of RI. Experimental results show that the sensor has a high sensitivity of RI at 557.74 nm/RIU in the measurement range of 1.33–1.42. The total structural length of SLPFG is only 5.4 mm, which is beneficial for integrated applications. In addition, the sensor achieves good stability, repeatability and strong mechanical properties, which has broad application prospects in environmental monitoring, biochemical monitoring, medical diagnosis and other aspects.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104123"},"PeriodicalIF":2.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simultaneously identify multi-location disturbance events based on SR-CNN and 2D-TCN in ϕ-OTDR system","authors":"Xuepeng Li,&nbsp;Shuqin Lou,&nbsp;Wei Gao,&nbsp;Yuying Guo,&nbsp;Xin Wang","doi":"10.1016/j.yofte.2025.104130","DOIUrl":"10.1016/j.yofte.2025.104130","url":null,"abstract":"<div><div>To tackle with the issue that different types of disturbance events will occur at different locations simultaneously in the phase-sensitive optical time-domain reflectometer (ϕ-OTDR) system, a multi-location disturbance event identification method based on Static Regional Convolutional Network (SR-CNN) and 2D Temporal Convolution Network (2D-TCN) is proposed. Taking use of SR-CNN, the 25 km-long sensing fiber is divided into 10 regions and the target region where disturbance events occur can be preliminarily identified. The 2D-TCN is introduced to identify the types of disturbance events as well as their precise locations. Experimental results show that, the different types of disturbance events simultaneously occur at 5 locations can be effectively identified with an average identification accuracy of 93.76 %. Even when the 5 locations are in different target regions, the identification accuracy can still exceed 92.78 %, with an identification time of only 0.77 s. The high identification accuracy, short identification time, and multi-location identification make this method of great value in the application of ϕ-OTDR system.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104130"},"PeriodicalIF":2.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A dual-parameter fiber optic sensor based on FP-WGM composite microcavities","authors":"Jun Liu ,&nbsp;Lu Cai ,&nbsp;Xu-wen Xie ,&nbsp;Zhi-wei Zhang ,&nbsp;Fu-cheng Xiang","doi":"10.1016/j.yofte.2024.104002","DOIUrl":"10.1016/j.yofte.2024.104002","url":null,"abstract":"<div><div>A composite fiber sensor integrating double Fabry-Perot interferometers (FPIs) and a whispering gallery mode (WGM) resonator was fabricated to simultaneously measure temperature and concentration. The microsphere resonator is a compact, composite all-fiber optic sensor manufactured by processing hollow core fiber (HCF) and single mode fiber (SMF). Rather than merely connecting FPI and WGM in series, the sensor exploits dual-FP interference and WGM resonance within the same microsphere cavity, which can simultaneously measure temperature and concentration while mitigating temperature-induced crosstalk in liquid concentration detection, offering a valuable platform for precise concentration measurement. Experimental results demonstrate that the composite sensor possesses a temperature sensitivity of 12.58 pm/°C and a concentration sensitivity of 75.70 pm/% with good linearity. The sensor boasts advantages including simple fabrication, low cost, compact size, and excellent stability, rendering it highly beneficial for diverse practical applications, notably in concentration measurements.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104002"},"PeriodicalIF":2.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}