Pub Date : 2025-01-23DOI: 10.1016/j.yofte.2025.104136
Chao Liu , Yuan Sun , Yanshu Zeng , Wei Liu , Jingwei Lv , Lin Yang , Jianxin Wang , Qiang Liu , Paul K. Chu
Terahertz (THz) polarization beam splitters (PBS) are valuable for applications in areas such as wireless high-speed communications and terahertz imaging. In this paper, a dual-core terahertz photonic crystal fiber (PCF) polarization beam splitter is proposed to achieve short length, high extinction ratio and wide bandwidth. This PBS has a cyclic olefin copolymer (COC) as the base material, and the dual-core structure is realized by introducing a central air hole. Performance analysis, conducted using the finite element method, reveals that the proposed PBS achieves a minimum length of 29.50688 mm, a bandwidth of 0.19 THz between 0.47 THz and 0.66 THz, and a maximum extinction ratio of −324.257 dB at an incident light frequency of 0.54 THz, where the two polarization modes are nearly completely separated. In addition, the PBS exhibits good manufacturing tolerances with a structural error of ± 1 %. These excellent properties indicate that THz PCF-PBS has great potential for applications in terahertz-band optical communication, optical sensing and optoelectronic detection.
{"title":"An ultra-high extinction ratio broadband photonic crystal fiber splitter designed for the terahertz band","authors":"Chao Liu , Yuan Sun , Yanshu Zeng , Wei Liu , Jingwei Lv , Lin Yang , Jianxin Wang , Qiang Liu , Paul K. Chu","doi":"10.1016/j.yofte.2025.104136","DOIUrl":"10.1016/j.yofte.2025.104136","url":null,"abstract":"<div><div>Terahertz (THz) polarization beam splitters (PBS) are valuable for applications in areas such as wireless high-speed communications and terahertz imaging. In this paper, a dual-core terahertz photonic crystal fiber (PCF) polarization beam splitter is proposed to achieve short length, high extinction ratio and wide bandwidth. This PBS has a cyclic olefin copolymer (COC) as the base material, and the dual-core structure is realized by introducing a central air hole. Performance analysis, conducted using the finite element method, reveals that the proposed PBS achieves a minimum length of 29.50688 mm, a bandwidth of 0.19 THz between 0.47 THz and 0.66 THz, and a maximum extinction ratio of −324.257 dB at an incident light frequency of 0.54 THz, where the two polarization modes are nearly completely separated. In addition, the PBS exhibits good manufacturing tolerances with a structural error of ± 1 %. These excellent properties indicate that THz PCF-PBS has great potential for applications in terahertz-band optical communication, optical sensing and optoelectronic detection.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104136"},"PeriodicalIF":2.6,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129658","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}
Pub Date : 2025-01-22DOI: 10.1016/j.yofte.2025.104140
Chulun Lin , Taixia Shi , Yiqing Liu , Yang Chen
A novel microwave photonic scheme for secure data transmission in optical fibers is proposed. The security of the scheme is guaranteed by physical encryption and decryption via the temporal Talbot effect in dispersive mediums. First, the original data is randomized in the digital domain by performing an exclusive OR operation using a random matrix. Subsequently, a time-varying multi-tone electrical signal, which represents the randomized data matrix, is modulated onto an optical carrier. The optical signal after modulation is then phase-modulated by a temporal Talbot array illuminator (TAI) signal, and the optical signal after discrete quadratic phase modulation will lose its original appearance in the frequency domain and be further dispersed in the first dispersive medium. Due to the dispersion that does not match the TAI signal exactly, the waveform after the first dispersive medium is a noise-like signal. Hence, the physical encryption of the original data is successfully achieved. As the optical signal passes a second dispersive medium that makes the total dispersion match the TAI signal, the temporal waveform of the noise-like signal after photodetection is transformed into pulses. “1” and “0” in the randomized data matrix are represented through the presence and absence of pulses, and the physical decryption is achieved. By further processing the recovered data matrix using the random matrix, the original data can be recovered. The physical layer security of the proposed scheme and its fiber transmission capability are demonstrated. 8-Gbit/s data is transmitted, encrypted, and decrypted using two dispersive mediums and an optical fiber of 10 to 200 km, and error-free transmission is achieved. Many factors that affect the encryption, decryption, and transmission performance of the system have been analyzed.
{"title":"Photonics-based physical encryption and decryption for secure data transmission leveraging the Talbot effect","authors":"Chulun Lin , Taixia Shi , Yiqing Liu , Yang Chen","doi":"10.1016/j.yofte.2025.104140","DOIUrl":"10.1016/j.yofte.2025.104140","url":null,"abstract":"<div><div>A novel microwave photonic scheme for secure data transmission in optical fibers is proposed. The security of the scheme is guaranteed by physical encryption and decryption via the temporal Talbot effect in dispersive mediums. First, the original data is randomized in the digital domain by performing an exclusive OR operation using a random matrix. Subsequently, a time-varying multi-tone electrical signal, which represents the randomized data matrix, is modulated onto an optical carrier. The optical signal after modulation is then phase-modulated by a temporal Talbot array illuminator (TAI) signal, and the optical signal after discrete quadratic phase modulation will lose its original appearance in the frequency domain and be further dispersed in the first dispersive medium. Due to the dispersion that does not match the TAI signal exactly, the waveform after the first dispersive medium is a noise-like signal. Hence, the physical encryption of the original data is successfully achieved. As the optical signal passes a second dispersive medium that makes the total dispersion match the TAI signal, the temporal waveform of the noise-like signal after photodetection is transformed into pulses. “1” and “0” in the randomized data matrix are represented through the presence and absence of pulses, and the physical decryption is achieved. By further processing the recovered data matrix using the random matrix, the original data can be recovered. The physical layer security of the proposed scheme and its fiber transmission capability are demonstrated. 8-Gbit/s data is transmitted, encrypted, and decrypted using two dispersive mediums and an optical fiber of 10 to 200 km, and error-free transmission is achieved. Many factors that affect the encryption, decryption, and transmission performance of the system have been analyzed.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104140"},"PeriodicalIF":2.6,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129100","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}
Pub Date : 2025-01-22DOI: 10.1016/j.yofte.2024.104112
Kaiyuan Feng , Du Wang , Mingli Dong , Xiaoping Lou , Yiqun Zhang , Chaofan Deng , Lianqing Zhu
A long short-term memory kolmogorov-arnold network (LSTM-KAN) computational model that can accurately estimate the loads of an aircraft landing gear is proposed, which can accurately estimate the loads based on monitoring the strain distribution of the landing gear structure. First, the ground strain load test system based on the landing gear structure is built. Fiber-optic grating strain sensors were installed at the monitoring positions of the landing gear, and the strain data under various loading conditions were collected using the loading system. Experimental datasets for model training and testing were generated based on the obtained strain and load data, the strain-load calculation model was trained and tested, and its prediction results were compared with the traditional linear regression method and other algorithms using the same experimental datasets. The load prediction results show that the maximum absolute percentage errors of the loads in the three directions are 2.74 %, 2.41 % and 3.29 %, respectively, and the corresponding root-mean-square errors are 51.31 N, 202.29 N and 39.86 N, respectively, and the overall average absolute percentage errors are reduced to less than 1 %, and the three-direction ones are 0.81 %, 0.73 % and 0.88 %, respectively, which proves that the LSTM-KAN model has better performance than the multiple linear regression method and other neural network algorithms, and can be effectively and accurately predicted in the field of health monitoring of aircraft landing gears and other aircraft structures.
{"title":"Aircraft landing gear load prediction based on LSTM-KAN network","authors":"Kaiyuan Feng , Du Wang , Mingli Dong , Xiaoping Lou , Yiqun Zhang , Chaofan Deng , Lianqing Zhu","doi":"10.1016/j.yofte.2024.104112","DOIUrl":"10.1016/j.yofte.2024.104112","url":null,"abstract":"<div><div>A long short-term memory kolmogorov-arnold network (LSTM-KAN) computational model that can accurately estimate the loads of an aircraft landing gear is proposed, which can accurately estimate the loads based on monitoring the strain distribution of the landing gear structure. First, the ground strain load test system based on the landing gear structure is built. Fiber-optic grating strain sensors were installed at the monitoring positions of the landing gear, and the strain data under various loading conditions were collected using the loading system. Experimental datasets for model training and testing were generated based on the obtained strain and load data, the strain-load calculation model was trained and tested, and its prediction results were compared with the traditional linear regression method and other algorithms using the same experimental datasets. The load prediction results show that the maximum absolute percentage errors of the loads in the three directions are 2.74 %, 2.41 % and 3.29 %, respectively, and the corresponding root-mean-square errors are 51.31 N, 202.29 N and 39.86 N, respectively, and the overall average absolute percentage errors are reduced to less than 1 %, and the three-direction ones are 0.81 %, 0.73 % and 0.88 %, respectively, which proves that the LSTM-KAN model has better performance than the multiple linear regression method and other neural network algorithms, and can be effectively and accurately predicted in the field of health monitoring of aircraft landing gears and other aircraft structures.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104112"},"PeriodicalIF":2.6,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129656","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}
Pub Date : 2025-01-22DOI: 10.1016/j.yofte.2025.104134
Atefeh Bagherzadeh , Akbar Ghaffarpour Rahbar , Yaghoub Khorasani
Elastic Optical Network with Space Division Multiplexing (SDM-EON) is considered as a suitable platform for providing the bandwidth required to meet the growing needs of Internet traffic. Bandwidth fragmentation, crosstalk and energy consumption are among the most important issues raised in EON. Reducing energy reduces costs, and fragmentation management leads to increased utilization of the spectrum. Crosstalk is also a parameter that, if not managed, will severely reduce the quality of transmission. In this paper, we present two novel algorithms, called REFC (Reduction of Energy consumption, Fragmentation and Crosstalk) and quality of service-enabled REFC (REFC-QoS) to handle prioritized incoming requests. For an arriving connection, REFC considers energy reduction parameters in the first step and selects the route with the lowest energy consumption. In the second step, the cores are sorted based on fragmentation, and the core with the lowest fragmentation value is chosen. Finally, in the third step, suitable slots with the lowest amount of crosstalk are selected and allocated to the connection. The simulation results demonstrate that the REFC algorithm effectively reduces blocking probability in comparison to other proposed methods. The REFC in compare to EEG-HCS and ICXT-Aware algorithms, the value of Bandwidth Blocking probability in NSFNET, at least 12 % and in USNET at least 19 % have been reduced. Additionally, REFC effectively mitigates the negative impacts of bandwidth fragmentation. Besides, REFC-QoS satisfies the QoS requirements of prioritized incoming requests.
{"title":"REFC: Reduction of energy consumption, fragmentation and crosstalk in SDM-EON","authors":"Atefeh Bagherzadeh , Akbar Ghaffarpour Rahbar , Yaghoub Khorasani","doi":"10.1016/j.yofte.2025.104134","DOIUrl":"10.1016/j.yofte.2025.104134","url":null,"abstract":"<div><div>Elastic Optical Network with Space Division Multiplexing (SDM-EON) is considered as a suitable platform for providing the bandwidth required to meet the growing needs of Internet traffic. Bandwidth fragmentation, crosstalk and energy consumption are among the most important issues raised in EON. Reducing energy reduces costs, and fragmentation management leads to increased utilization of the spectrum. Crosstalk is also a parameter that, if not managed, will severely reduce the quality of transmission. In this paper, we present two novel algorithms, called REFC (Reduction of Energy consumption, Fragmentation and Crosstalk) and quality of service-enabled REFC (REFC-QoS) to handle prioritized incoming requests. For an arriving connection, REFC considers energy reduction parameters in the first step and selects the route with the lowest energy consumption. In the second step, the cores are sorted based on fragmentation, and the core with the lowest fragmentation value is chosen. Finally, in the third step, suitable slots with the lowest amount of crosstalk are selected and allocated to the connection. The simulation results demonstrate that the REFC algorithm effectively reduces blocking probability in comparison to other proposed methods. The REFC in compare to EEG-HCS and ICXT-Aware algorithms, the value of Bandwidth Blocking probability in NSFNET, at least 12 % and in USNET at least 19 % have been reduced. Additionally, REFC effectively mitigates the negative impacts of bandwidth fragmentation. Besides, REFC-QoS satisfies the QoS requirements of prioritized incoming requests.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104134"},"PeriodicalIF":2.6,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129657","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}
In this paper, a switchable wavelength-spaced adjustable multi-wavelength erbium-doped fiber actively Q-switched fiber laser based on EOM and parallel Lyot filters is proposed. In the experiment, the stable switchable output with different wavelength numbers can be achieved by adjusting the polarization controller of the parallel Lyot filter, and we obtained four kinds of double wavelengths with different wavelength spacing, seven kinds of triple wavelengths with different wavelength spacing, and three kinds of quadruple wavelengths with different wavelength spacing. With the increase of the pump power, the output wavelengths number can reach ten. In addition, single- and dual-pulse can be observed during modulation, and the dual-pulse interval can be adjusted from 35 µs to 38 µs. The wavelength spacing of the proposed laser, and the pulse spacing of the dual-pulse can be adjusted more flexibly. It has promising applications in laser therapy; optical measurements and laser imaging.
{"title":"Switchable and wavelength-spaced tunable multi-wavelength actively Q-switched fiber laser based on EOM and parallel Lyot filters","authors":"Yichen Li, Honggang Pan, Qingcheng You, Bin Li, Yukun Zhu, Rupeng Li, Chunqi Chen, Zihong Zhao","doi":"10.1016/j.yofte.2025.104138","DOIUrl":"10.1016/j.yofte.2025.104138","url":null,"abstract":"<div><div>In this paper, a switchable wavelength-spaced adjustable multi-wavelength erbium-doped fiber actively Q-switched fiber laser based on EOM and parallel Lyot filters is proposed. In the experiment, the stable switchable output with different wavelength numbers can be achieved by adjusting the polarization controller of the parallel Lyot filter, and we obtained four kinds of double wavelengths with different wavelength spacing, seven kinds of triple wavelengths with different wavelength spacing, and three kinds of quadruple wavelengths with different wavelength spacing. With the increase of the pump power, the output wavelengths number can reach ten. In addition, single- and dual-pulse can be observed during modulation, and the dual-pulse interval can be adjusted from 35 µs to 38 µs. The wavelength spacing of the proposed laser, and the pulse spacing of the dual-pulse can be adjusted more flexibly. It has promising applications in laser therapy; optical measurements and laser imaging.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104138"},"PeriodicalIF":2.6,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129589","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}
Pub Date : 2025-01-21DOI: 10.1016/j.yofte.2025.104141
Rong Lai, Fengnian Liu, Xin Guo, Zhenhe Zhang, Qing Zhong, Sheng Long
Narrow linewidth fiber laser (NLFL) with linear cavity based on saturable absorber (SA) have made great progress, but there are few research reports on a pair of fiber Bragg gratings (FBG) as cavity mirrors and the simplification of their structures through automated design. We have demonstrated a simple compact linear cavity NLFL design based on SA and have developed an engineering model for automated design and optimization. Firstly, we have simulated the theoretical model to analyze the different lengths of SA and to determine their optimal lengths by MATLAB. Subsequently, we have constructed linear cavity laser with narrow-linewidth output and have performed comparative experiments using the different lengths of SA to validate the simulation results. Experimental results have shown that the optimal lasing output with a full width at half maximum (FWHM) of 0.0124 nm and an optical signal-to-noise ratio (OSNR) of 65.867 dB has been achieved when the length of SA is 2.05 m, which has been consistent with the MATLAB simulation results. Additionally, we have compared the effect of pump power on linewidth with or without the SA. The results have shown that the linewidth of the laser has been optimized at a specific pump power with the addition of the SA. We have also observed that the laser output is mainly affected by the bandwidth and center wavelength of the low-reflectivity fiber Bragg grating (LR-FBG) at room temperature.
{"title":"Optimization of Narrow Linewidth Fiber Laser with Linear Cavity Based on Saturable Absorber","authors":"Rong Lai, Fengnian Liu, Xin Guo, Zhenhe Zhang, Qing Zhong, Sheng Long","doi":"10.1016/j.yofte.2025.104141","DOIUrl":"10.1016/j.yofte.2025.104141","url":null,"abstract":"<div><div>Narrow linewidth fiber laser (NLFL) with linear cavity based on saturable absorber (SA) have made great progress, but there are few research reports on a pair of fiber Bragg gratings (FBG) as cavity mirrors and the simplification of their structures through automated design. We have demonstrated a simple compact linear cavity NLFL design based on SA and have developed an engineering model for automated design and optimization. Firstly, we have simulated the theoretical model to analyze the different lengths of SA and to determine their optimal lengths by MATLAB. Subsequently, we have constructed linear cavity laser with narrow-linewidth output and have performed comparative experiments using the different lengths of SA to validate the simulation results. Experimental results have shown that the optimal lasing output with a full width at half maximum (FWHM) of 0.0124 nm and an optical signal-to-noise ratio (OSNR) of 65.867 dB has been achieved when the length of SA is 2.05 m, which has been consistent with the MATLAB simulation results. Additionally, we have compared the effect of pump power on linewidth with or without the SA. The results have shown that the linewidth of the laser has been optimized at a specific pump power with the addition of the SA. We have also observed that the laser output is mainly affected by the bandwidth and center wavelength of the low-reflectivity fiber Bragg grating (LR-FBG) at room temperature.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104141"},"PeriodicalIF":2.6,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129588","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}
Pub Date : 2025-01-21DOI: 10.1016/j.yofte.2025.104137
Meadhbh Healy , Andreas Baum , Francesco Musumeci
We consider the issue of data scarcity with class imbalance in failure-cause identification for optical fiber systems using Machine Learning (ML) techniques. We use an open dataset comprising of real Optical Time-Domain Reflectometer (OTDR) traces which have been gathered in an artificial setup spanning tens of kilometers, consistent with a long-haul network. Whilst ML methods have shown satisfactory results for automating the process of identifying failure causes in optical fiber networks, the solutions are generally strongly dependent on available labeled datasets, and require extensive data to train and validate any findings. However, in the case of failure management in optical networks, building a valuable dataset with sufficiently informative samples is in general a hard process, due to the fact that, by nature, failures occur infrequently. As such, data-labeling is time and resource intensive for domain experts. We therefore seek to mitigate these issues by exploring two generative models, namely, conditional Generative Adversarial Network (cGAN) and conditional Variational Autoencoder (cVAE), to balance the number of failures samples in a multiclass dataset. In order to balance the dataset with accurate synthetic data across the different failure causes, we adopt generative models that are conditioned on the failure classes, the SNR level of the trace and the maximum amplitude of the signal. These approaches are compared to Synthetic Minority Over-sampling TEchnique (SMOTE). We compare our approaches by training our datasets using an autoencoder classifier and testing them against three holdout datasets. Results show that, with the cGAN and cVAE, failure-cause identification can be improved by more than 5% in terms of global accuracy when compared to the imbalanced dataset, and in particular for scarcely-represented failure classes, our generative models provide an improvement in the f1 scores of over 50%.
{"title":"Addressing data scarcity in ML-based failure-cause identification in optical networks through generative models","authors":"Meadhbh Healy , Andreas Baum , Francesco Musumeci","doi":"10.1016/j.yofte.2025.104137","DOIUrl":"10.1016/j.yofte.2025.104137","url":null,"abstract":"<div><div>We consider the issue of data scarcity with class imbalance in failure-cause identification for optical fiber systems using Machine Learning (ML) techniques. We use an open dataset comprising of real Optical Time-Domain Reflectometer (OTDR) traces which have been gathered in an artificial setup spanning tens of kilometers, consistent with a long-haul network. Whilst ML methods have shown satisfactory results for automating the process of identifying failure causes in optical fiber networks, the solutions are generally strongly dependent on available labeled datasets, and require extensive data to train and validate any findings. However, in the case of failure management in optical networks, building a valuable dataset with sufficiently informative samples is in general a hard process, due to the fact that, by nature, failures occur infrequently. As such, data-labeling is time and resource intensive for domain experts. We therefore seek to mitigate these issues by exploring two generative models, namely, conditional Generative Adversarial Network (cGAN) and conditional Variational Autoencoder (cVAE), to balance the number of failures samples in a multiclass dataset. In order to balance the dataset with accurate synthetic data across the different failure causes, we adopt generative models that are conditioned on the failure classes, the SNR level of the trace and the maximum amplitude of the signal. These approaches are compared to Synthetic Minority Over-sampling TEchnique (SMOTE). We compare our approaches by training our datasets using an autoencoder classifier and testing them against three holdout datasets. Results show that, with the cGAN and cVAE, failure-cause identification can be improved by more than 5% in terms of global accuracy when compared to the imbalanced dataset, and in particular for scarcely-represented failure classes, our generative models provide an improvement in the f1 scores of over 50%.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104137"},"PeriodicalIF":2.6,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129590","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}
Pub Date : 2025-01-20DOI: 10.1016/j.yofte.2025.104132
Sen Zhu , Yulin Wang , Yunfan Xu , Yuefeng Qi , Yanyan Liu , Fang Zhang
We have designed a novel Convolutional Neural Network (CNN) model specifically developed for the demodulation of Fiber Bragg Grating (FBG) sensor networks. This model cleverly utilizes the Full Width at Half Maximum (FWHM) of the FBG as a key distinguishing feature, enabling it to differentiate between three asymmetrically overlapping spectra with identical wavelengths. Remarkably, the model accurately demodulates the central wavelength shift of each grating, even in scenarios where the waveforms of three gratings are completely overlapping. The results demonstrate that this approach significantly enhances the multiplexing capability of FBG sensors, allowing a spectral band originally assigned to a single grating to accommodate three grating sensors. The model achieved a mean absolute error (MAE) of 3.28 pm in demodulation accuracy. Additionally, the demodulation scheme exhibited robustness against noise; by employing a denoising method based on Coiflets wavelet transform, the model maintained a demodulation accuracy of 3.36 pm even in the presence of noise.
{"title":"Asymmetric fiber grating overlapping spectrum demodulation technology based on convolutional network and wavelet transform noise reduction","authors":"Sen Zhu , Yulin Wang , Yunfan Xu , Yuefeng Qi , Yanyan Liu , Fang Zhang","doi":"10.1016/j.yofte.2025.104132","DOIUrl":"10.1016/j.yofte.2025.104132","url":null,"abstract":"<div><div>We have designed a novel Convolutional Neural Network (CNN) model specifically developed for the demodulation of Fiber Bragg Grating (FBG) sensor networks. This model cleverly utilizes the Full Width at Half Maximum (FWHM) of the FBG as a key distinguishing feature, enabling it to differentiate between three asymmetrically overlapping spectra with identical wavelengths. Remarkably, the model accurately demodulates the central wavelength shift of each grating, even in scenarios where the waveforms of three gratings are completely overlapping. The results demonstrate that this approach significantly enhances the multiplexing capability of FBG sensors, allowing a spectral band originally assigned to a single grating to accommodate three grating sensors. The model achieved a mean absolute error (MAE) of 3.28 pm in demodulation accuracy. Additionally, the demodulation scheme exhibited robustness against noise; by employing a denoising method based on Coiflets wavelet transform, the model maintained a demodulation accuracy of 3.36 pm even in the presence of noise.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104132"},"PeriodicalIF":2.6,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129587","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}
Pub Date : 2025-01-18DOI: 10.1016/j.yofte.2025.104131
Mohd Narizee Mohd Nasir , G.Senthil Murugan , Michalis N. Zervas
A hybrid plasmonic whispering-gallery-mode (WGM) microbottle resonator (MBR) supporting hybridized surface plasmon polaritons (SPPs) is demonstrated. A thin gold film was deposited from one side of the MBR and covers only half of the resonator surface with a meniscus cross-section shape and tapered edges. Composite SPPs Q-factor of up to 850 is achievable through efficient coupling from the dielectric part of the hybrid-MBR. Lorentzian fitting on the measured data revealed that these composite SPPs comprised of three overlapping resonances with Q-factor of up to 2500. It is also shown that the excitation strength of the individual resonances depends on the relative orientation between the excitation tapered optical fibre and the thin gold meniscus. FDTD modelling reproduced accurately the experimental spectral characteristics.
{"title":"Hybrid plasmonic whispering gallery mode microbottle resonator","authors":"Mohd Narizee Mohd Nasir , G.Senthil Murugan , Michalis N. Zervas","doi":"10.1016/j.yofte.2025.104131","DOIUrl":"10.1016/j.yofte.2025.104131","url":null,"abstract":"<div><div>A hybrid plasmonic whispering-gallery-mode (WGM) microbottle resonator (MBR) supporting hybridized surface plasmon polaritons (SPPs) is demonstrated. A thin gold film was deposited from one side of the MBR and covers only half of the resonator surface with a meniscus cross-section shape and tapered edges. Composite SPPs <em>Q</em>-factor of up to 850 is achievable through efficient coupling from the dielectric part of the hybrid-MBR. Lorentzian fitting on the measured data revealed that these composite SPPs comprised of three overlapping resonances with <em>Q</em>-factor of up to 2500. It is also shown that the excitation strength of the individual resonances depends on the relative orientation between the excitation tapered optical fibre and the thin gold meniscus. FDTD modelling reproduced accurately the experimental spectral characteristics.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104131"},"PeriodicalIF":2.6,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129586","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}
Pub Date : 2025-01-13DOI: 10.1016/j.yofte.2024.104121
Yan Zhao , Jianxun Gao , Dianyin Hu , Zhimin Jiang , Xuemin Wang , Jinchao Pan , Rongqiao Wang
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.
{"title":"Online monitoring of fatigue crack under variable amplitude loading driven by multispectral features fusion of FBG sensors","authors":"Yan Zhao , Jianxun Gao , Dianyin Hu , Zhimin Jiang , Xuemin Wang , Jinchao Pan , 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}