{"title":"Hybrid implementation of OCDR and BOCDR","authors":"Haruyuki Kubota , Guangtao Zhu , Seiga Ochi , Takahiro Ishimaru , Hiroshi Takahashi , Kunihiro Toge , Yosuke Mizuno","doi":"10.1016/j.yofte.2025.104129","DOIUrl":"10.1016/j.yofte.2025.104129","url":null,"abstract":"<div><div>We propose a hybrid implementation of optical correlation-domain reflectometry (OCDR) and Brillouin optical correlation-domain reflectometry (BOCDR), which conventionally required independent experimental setups, enabling simultaneous measurements of the distributions of reflectivity and strain along a fiber under test. Through experimental demonstrations, we highlight the system’s capability to distinguish whether changes in reflectivity are caused by strain or temperature variations. This capability holds significant promise for expanding the applications of OCDR and BOCDR in the health diagnostics of infrastructures and fiber networks. The advantages and limitations of this hybrid system are also discussed in comparison with time-domain hybrid approaches.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104129"},"PeriodicalIF":2.6,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Botella-Campos, J. Romero-Huedo, J. Mora, B. Ortega
{"title":"Convergent optical fronthaul link for wireless access over different spectral bands","authors":"M. Botella-Campos, J. Romero-Huedo, J. Mora, B. Ortega","doi":"10.1016/j.yofte.2024.104114","DOIUrl":"10.1016/j.yofte.2024.104114","url":null,"abstract":"<div><div>We demonstrate a convergent optical fronthaul link for enabling heterogeneous wireless access technologies in 6G future networks deployment based on a directly modulated laser and an external Mach–Zehnder modulator biased at null point for optical frequency multiplying. Simultaneous transmission of two M-QAM data signals over baseband and millimeter wave (mmW) frequency band, i.e. 42 GHz, is demonstrated over a 10 km fiber link, showing the suitability for visible light communications and mmW radio access, respectively, to the final user. System intermodulation in mmW band is identified under high received optical power levels and overcome by inserting a dispersion compensation module.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104114"},"PeriodicalIF":2.6,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"High-precision optical fiber sensor system with a novel interrogation system","authors":"Ching-Hung Chang, Wei-Che Yen, Guan-Jhang Huang, Chia-Heng Tsai","doi":"10.1016/j.yofte.2024.104124","DOIUrl":"10.1016/j.yofte.2024.104124","url":null,"abstract":"<div><div>A novel high-precision optical fiber sensor system is proposed and experimentally demonstrated. In order to simultaneously enhance the sensitivity, and detection range of the sensor system, the fiber laser technique, optical heterodyne detection method, and frequency hopping technique are integrated and employed to detect both tiny and unobservable variations over a large measuring range in the sensing values. Besides, to further optimize the sensitivity and stability of the system, a custom-designed RF-Signal Analyzing System (RF-SAS) is used to overcome fiber laser wavelength-vibration effect and extract desired and accurate values from noised-like sensing signals. Experimental results show that when different weights are gradually hung vertically on the FBG sensor to give corresponding strains, the proposed sensing system can simultaneously support high-accurate detection over a wide and extensible detection range. Every 1 mg strain variation can be detected clearly when the strain is increased from 0 mg to 30,000 mg or more.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104124"},"PeriodicalIF":2.6,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129108","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}
Nurul Farah Adilla Zaidi , Muhammad Yusof Mohd Noor , Nur Najahatul Huda Saris , Mohd Rashidi Salim , Sumiaty Ambran , Azizul Azizan , Raja Kamarulzaman Raja Ibrahim , Fauzan Ahmad , Nurul Ashikin Daud , Norazida Ali , Norizan Mohamed Nawawi , Ian Yulianti , Gang-Ding Peng
{"title":"AI-powered MMI fiber sensors for wide-range refractive index detection using neural networks algorithm","authors":"Nurul Farah Adilla Zaidi , Muhammad Yusof Mohd Noor , Nur Najahatul Huda Saris , Mohd Rashidi Salim , Sumiaty Ambran , Azizul Azizan , Raja Kamarulzaman Raja Ibrahim , Fauzan Ahmad , Nurul Ashikin Daud , Norazida Ali , Norizan Mohamed Nawawi , Ian Yulianti , Gang-Ding Peng","doi":"10.1016/j.yofte.2024.104113","DOIUrl":"10.1016/j.yofte.2024.104113","url":null,"abstract":"<div><div>This research presents an artificial intelligence (AI)-driven machine learning (ML) approach for accurately measuring refractive index (RI) values across both lower and higher regimes than the fiber material’s RI, using a simple single multimode interference (MMI) fiber sensor. The sensor configuration consists of a no-core fiber (NCF) segment between two single-mode fiber (SMF) sections. A Bilayer Neural Network (BNN) regression model is employed to predict both low refractive index (LRI) and high refractive index (HRI) regimes, achieving a broad dynamic measurement range from 1.3000 RIU to 1.3900 RIU for LRI regime and from 1.4600 RIU to 1.5500 RIU for HRI regime. The model demonstrates 99.7% accuracy and a low root mean square error (RMSE) of 0.0044, ensuring that predicted RI values closely match actual measurements without any RI ambiguity. Furthermore, the all-silica NCF structure is inherently resistant to temperature fluctuations, enabling its deployment in environments with varying temperatures without requiring additional temperature compensation mechanisms.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104113"},"PeriodicalIF":2.6,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129645","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":"Enhanced soliton steering in PT-symmetric couplers with nonlocal interactions","authors":"S.M. Al-Marzoug","doi":"10.1016/j.yofte.2024.104117","DOIUrl":"10.1016/j.yofte.2024.104117","url":null,"abstract":"<div><div>This study investigated the enhanced dynamics of solitons in PT-symmetric couplers with nonlocal interactions. PT-symmetric waveguide arrays, characterized by balanced gain and loss, exhibit unique properties such as nonreciprocal light propagation and unidirectional invisibility. By incorporating nonlocal interactions, where the response at a point depends on the extended region’s state, we explore how these couplers achieve superior soliton stability, reduced critical power, and improved transmission efficiency. Numerical simulations reveal that PT-symmetric couplers with nonlocal terms significantly outperform conventional couplers in terms of steering dynamics, energy transfer, and phase coherence. The results demonstrate that nonlocal interactions, whether focusing or defocusing, play a crucial role in optimizing soliton propagation in PT-symmetric systems. These findings provide valuable insights for designing high-performance optical devices, highlighting the potential of PT-symmetric waveguide arrays with nonlocal nonlinearities to revolutionize optical communication technologies. This research underscores the importance of nonlocal interactions in enhancing the capabilities of PT-symmetric optical systems.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104117"},"PeriodicalIF":2.6,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129655","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":"An optical fiber high-precision absolute distance measurement technology incorporating white-light interferometry and single-wavelength interferometry","authors":"Jinxu Jia, Fang Xie, Sitong Bao","doi":"10.1016/j.yofte.2024.104115","DOIUrl":"10.1016/j.yofte.2024.104115","url":null,"abstract":"<div><div>An optical fiber high-precision absolute distance measurement technology that incorporates white-light interferometry and single-wavelength interferometry is presented, which is suitable for measuring static or quasi-static local absolute distance as well as remote absolute distance. The sensing head which is a grin lens and is connected to an optical fiber Michelson interferometer with optical fiber can be installed conveniently in the sensing field to sense the measured absolute distance. The optical fiber Michelson interferometer is used to demodulate the optical path. The white light interferometric signal of the Michelson interferometer is used to determine the amplitude of the absolute distance, while the value of the absolute distance is measured precisely with a single wavelength interferometric signal which is obtained with a fiber Bragg grating reflecting a single wavelength from the white light interferometric signal. The measurement resolution that is determined by the single wavelength interferometry is less than 1 nm. And the measurement range that is determined by the coherent length of the light reflected by the fiber Bragg grating is about 12 mm. The linear correlation coefficient of the experimental results of absolute distance measurement is 0.999 which indicates that the linearity of the measurement system is very good.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104115"},"PeriodicalIF":2.6,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129647","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}
Anting Xu , Mingzhu Yin , Wei Wang , Liming Chen , Fan Li
{"title":"Sturdy-multistage noise-shaping delta-sigma modulator with enhanced noise-coupling and NTF-optimized strategy for intermediate frequency digital mobile fronthaul","authors":"Anting Xu , Mingzhu Yin , Wei Wang , Liming Chen , Fan Li","doi":"10.1016/j.yofte.2024.104110","DOIUrl":"10.1016/j.yofte.2024.104110","url":null,"abstract":"<div><div>In this paper, digital mobile fronthaul (MFH) based on the enhanced noise-coupling structure for intermediate frequency (IF) scenarios and noise transfer function (NTF)-optimized strategy sturdy multi-stage noise-shaping delta-sigma (SMASH) modulator is proposed. Without the need for additional integrators, the SMASH modulator with enhanced noise-coupling (SMASH-NC) gains two extra zeros in the signal band, improving the second-order noise shaping capability and achieving a 13.6 dB signal-to-noise rate (SNR) improvement. The NTF-optimized strategy based on genetic algorithm (GA) is proposed to design SMASH-NC. Compared with the SMASH-NC obtained by traditional method, the stability of SMASH-NC of GA method is higher, which supports larger input signals, with a 4.1 dB SNR improvement. We experimentally demonstrate the transmission of orthogonal frequency division multiplexing (OFDM) signals in MFH with the fourth-order SMASH-NC modulator. The OFMD signals at the center frequency of 1.5 GHz are modulated to 5-Gbaud 4-level pulse amplitude modulation (PAM4) signals through the SMASH-NC modulator and transmitted over the intensity modulation direct detection (IM/DD) link and 20 km single-mode fiber (SMF). Experimental results show that OFDM signals can be transmitted up to 65,536 quadrature amplitude modulation (QAM) with the SNR of 52.41 dB. In addition, the fourth-order SMASH-NC scheme has 9.52 % less adders and 29.17 % less multipliers, respectively, in comparison to the traditional fourth-order single-loop delta-sigma modulator (SDSM) scheme.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104110"},"PeriodicalIF":2.6,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129027","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}
Jia Lu , Tianshuo Wang , Jie Ma , Jianfei Liu , Xiangye Zeng , Yang Wang
{"title":"Performance analysis of geometrically shaped 16/32/64/128QAM based on swarm intelligence algorithm","authors":"Jia Lu , Tianshuo Wang , Jie Ma , Jianfei Liu , Xiangye Zeng , Yang Wang","doi":"10.1016/j.yofte.2024.104111","DOIUrl":"10.1016/j.yofte.2024.104111","url":null,"abstract":"<div><div>In this paper, an optimization scheme for geometrically shaped quadrature amplitude modulation (GS-QAM) based on swarm intelligence algorithms is proposed. The swarm intelligence algorithms of the marine predator algorithm (MPA), nonlinear marine predator algorithm (NMPA), mountain gazelle optimizer (MGO), dog optimization algorithm (DOA), and honey badger algorithm (HBA) are used to optimize the geometrical locations of the constellation points to reduce the damage caused by phase noise and improve the system performance. The results show that the scheme improves the optical signal-to-noise ratio (OSNR) gain by 1.4 dB/1.6 dB/2.8 dB/4.3 dB, compared with the standard 16/32/64/128 QAM signals and the optimization effect becomes more obvious as the modulation order increases. The five algorithms also significantly improve the performance of the system in terms of transmission distance and transmission rate. In addition, the scheme further validates the universality of the proposed optimization scheme for different modulation formats and demonstrates its potential application to higher-order signals.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104111"},"PeriodicalIF":2.6,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129028","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}
Juan A. Zepeda-Galvez, Wiktor Walasik, Robert E. Tench, Alexandre Amavigan, Jean-Marc Delavaux
{"title":"Broadband tunable PM holmium doped ring fiber laser for the 2000–2100 nm band","authors":"Juan A. Zepeda-Galvez, Wiktor Walasik, Robert E. Tench, Alexandre Amavigan, Jean-Marc Delavaux","doi":"10.1016/j.yofte.2024.104105","DOIUrl":"10.1016/j.yofte.2024.104105","url":null,"abstract":"<div><div>We report the experimental performance of a tunable polarization-maintaining (PM) holmium-doped fiber ring laser, followed by a single-clad single-stage holmium-doped fiber amplifier. An average output power of 1.6 W over a tuning range of 100 nm (from 2000 to 2100 nm) was obtained for 6.5 W of total launched pump power at 1860 nm, corresponding to an optical-to-optical efficiency of 32 %. We measured an optical signal-to-noise ratio (OSNR) larger than 42 dB/0.05 nm and a polarization extinction ratio (PER) larger than 19.6 dB. The long-term power stability exhibited a peak-to-peak variation of 1.2 % over 2 h, and the experimentally measured spectral width of the laser was 530 MHz.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104105"},"PeriodicalIF":2.6,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129029","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}
Chang-Jia Wang, Xin Gui, Xue-Lei Fu, Yi-Bing Wang, Zheng-Ying Li
{"title":"Valve internal leakage detection technology using fiber optic accelerometers for vibration sensing","authors":"Chang-Jia Wang, Xin Gui, Xue-Lei Fu, Yi-Bing Wang, Zheng-Ying Li","doi":"10.1016/j.yofte.2024.104106","DOIUrl":"10.1016/j.yofte.2024.104106","url":null,"abstract":"<div><div>This paper introduces a technique for detecting internal leaks in valves based on fiber optic vibration sensing in oil and gas transfer stations, where traditional electrical sensors are limited due to safety concerns. The study establishes a link between the vibration signals and the leak’s characteristics, showing that a larger pipeline diameter or Young’s modulus results in higher characteristic frequencies, and smaller leak orifices or higher pressures increase the signal amplitude. A high-sensitivity fiber optic accelerometer sensor is developed, capable of detecting vibrations from 10 Hz to 2 kHz with a sensitivity of 26.5 dB and a flatness of <span><math><mo>±</mo></math></span>1 dB. Experiments confirmed that the sensor can detect leaks as low as 75 mL/min. This method has been successfully implemented in oil and gas pipeline transfer stations, providing accurate and sensitive leak detection. Its anti-electromagnetic interference and intrinsic safety make it suitable for flammable and explosive detection environments.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"90 ","pages":"Article 104106"},"PeriodicalIF":2.6,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143129109","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}