Pub Date : 2025-12-01Epub Date: 2025-10-09DOI: 10.1016/j.yofte.2025.104426
ShiTong Zhong , GongQiang Li , HaiTao Yan , DaoFu Han
We propose a humidity sensor with temperature compensation based on optical carrier interference (OCMI) and an enhanced Vernier effect. The sensor head consists of a sensing fiber Bragg grating (FBG) bonded with a polyimide (PI) tube and two reference FBGs with special packaging. The interferograms formed by the two reference FBGs and the sensing FBG superimpose to generate a Vernier effect. Due to the opposite directional shifts of the two interferograms with respect to humidity variations, an enhanced Vernier effect is further achieved. The humidity sensitivity of the enhanced Vernier effect is −3.867 MHz/%RH amplified by a factor −56.7 and 56.8 respectively compared to the individual OCMIs. The temperature sensitivity of the reference FBGs with specialized packaging closely matches that of the sensing FBG, ensuring effective temperature compensation within the system.
{"title":"Polyimide tube-encapsulated FBG sensor with temperature compensation based on OCMI and Vernier effect for humidity measurement","authors":"ShiTong Zhong , GongQiang Li , HaiTao Yan , DaoFu Han","doi":"10.1016/j.yofte.2025.104426","DOIUrl":"10.1016/j.yofte.2025.104426","url":null,"abstract":"<div><div>We propose a humidity sensor with temperature compensation based on optical carrier interference (OCMI) and an enhanced Vernier effect. The sensor head consists of a sensing fiber Bragg grating (FBG) bonded with a polyimide (PI) tube and two reference FBGs with special packaging. The interferograms formed by the two reference FBGs and the sensing FBG superimpose to generate a Vernier effect. Due to the opposite directional shifts of the two interferograms with respect to humidity variations, an enhanced Vernier effect is further achieved. The humidity sensitivity of the enhanced Vernier effect is −3.867 MHz/%RH amplified by a factor −56.7 and 56.8 respectively compared to the individual OCMIs. The temperature sensitivity of the reference FBGs with specialized packaging closely matches that of the sensing FBG, ensuring effective temperature compensation within the system.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"95 ","pages":"Article 104426"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267581","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}
It is known that passive harmonic mode-locking (HML) is a widely used technique to achieve high pulse repetition rates in fiber lasers. We present, to the best of our knowledge, the first demonstration of harmonically mode-locked Er-doped fiber laser with sub-GHz repetition rate based on a nonlinear amplified loop mirror (NALM). This fully spliced, polarization-maintaining (PM) fiber configuration operates in a self-starting regime, delivering high-frequency pulse trains with significantly enhanced stability against environmental perturbations. The laser achieves a maximum pulse repetition rate (PRR) of ∼ 630 MHz, corresponding to the 242nd cavity harmonic. Furthermore, we apply a supermode noise mitigation technique using continuous-wave (CW) injection from an external narrow-band source successfully stabilizing the HML operation and reducing timing jitter by more than a factor of two across the entire range of observed repetition rates. This novel design provides a robust, adjustment-free solution for high-frequency operation with exceptional stability, meeting the demands of precision and reliability required for advanced applications.
{"title":"Harmonic mode-locking in All-PM Er-doped fiber laser NALM configuration","authors":"V.A. Ribenek , D.A. Korobko , D.A. Stoliarov , P.A. Itrin , G.V. Tertyshnikova , A.A. Fotiadi","doi":"10.1016/j.yofte.2025.104392","DOIUrl":"10.1016/j.yofte.2025.104392","url":null,"abstract":"<div><div>It is known that passive harmonic mode-locking (HML) is a widely used technique to achieve high pulse repetition rates in fiber lasers. We present, to the best of our knowledge, the first demonstration of harmonically mode-locked Er-doped fiber laser with sub-GHz repetition rate based on a nonlinear amplified loop mirror (NALM). This fully spliced, polarization-maintaining (PM) fiber configuration operates in a self-starting regime, delivering high-frequency pulse trains with significantly enhanced stability against environmental perturbations. The laser achieves a maximum pulse repetition rate (PRR) of ∼ 630 MHz, corresponding to the 242nd cavity harmonic. Furthermore, we apply a supermode noise mitigation technique using continuous-wave (CW) injection from an external narrow-band source successfully stabilizing the HML operation and reducing timing jitter by more than a factor of two across the entire range of observed repetition rates. This novel design provides a robust, adjustment-free solution for high-frequency operation with exceptional stability, meeting the demands of precision and reliability required for advanced applications.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"95 ","pages":"Article 104392"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145011172","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 : 2025-12-01Epub Date: 2025-10-14DOI: 10.1016/j.yofte.2025.104451
Jianing Cao , Peng Wang , Jinbao Chen , Pu Zhou , Xiaoming Xi , Xiaoyong Xu , Hanshuo Wu , Hanwei Zhang , Xiaolin Wang
This study presents a comprehensive investigation of high-power dichroic mirror spectral beam combination (DM-SBC) system with active tilt control through theoretical analysis and experimental validation. First, we establish an active-tilt-control simulation utilizing the stochastic parallel gradient descent (SPGD) algorithm, systematically examining the influence of key algorithm parameters including the gain coefficient γ and iteration frequency f on the combining performance. Experimental implementation successfully demonstrates DM-SBC integration of three custom-developed kW-level fiber lasers with central wavelengths at 1050 nm, 1070 nm, and 1085 nm, achieving a maximum combined output power of 12 kW. The activation of active tilt control yields significant beam quality improvements, reducing average M2 values from 2.8/1.7 (x/y directions) to 1.8/1.6, while enhancing the metric function J by approximately two orders of magnitude. Both numerical simulations and experimental measurements consistently demonstrate the effectiveness of the proposed active control scheme in optimizing DM-SBC performance, particularly in beam quality enhancement and system stability improvement.
{"title":"12-kW high power spectral beam combination employing dichroic mirror with active tilt control: simulation and experimental demonstration","authors":"Jianing Cao , Peng Wang , Jinbao Chen , Pu Zhou , Xiaoming Xi , Xiaoyong Xu , Hanshuo Wu , Hanwei Zhang , Xiaolin Wang","doi":"10.1016/j.yofte.2025.104451","DOIUrl":"10.1016/j.yofte.2025.104451","url":null,"abstract":"<div><div>This study presents a comprehensive investigation of high-power dichroic mirror spectral beam combination (DM-SBC) system with active tilt control through theoretical analysis and experimental validation. First, we establish an active-tilt-control simulation utilizing the stochastic parallel gradient descent (SPGD) algorithm, systematically examining the influence of key algorithm parameters including the gain coefficient γ and iteration frequency <em>f</em> on the combining performance. Experimental implementation successfully demonstrates DM-SBC integration of three custom-developed kW-level fiber lasers with central wavelengths at 1050 nm, 1070 nm, and 1085 nm, achieving a maximum combined output power of 12 kW. The activation of active tilt control yields significant beam quality improvements, reducing average M<sup>2</sup> values from 2.8/1.7 (x/y directions) to 1.8/1.6, while enhancing the metric function <em>J</em> by approximately two orders of magnitude. Both numerical simulations and experimental measurements consistently demonstrate the effectiveness of the proposed active control scheme in optimizing DM-SBC performance, particularly in beam quality enhancement and system stability improvement.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"95 ","pages":"Article 104451"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145320691","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 : 2025-12-01Epub Date: 2025-09-12DOI: 10.1016/j.yofte.2025.104388
Hasan Cihangir , Murat Yücel
Tunable laser source (TLS), doped fiber (PDF), and pump laser are the main design components for the praseodymium doped fiber amplifier (PDFA) design. Determination of the important parameter values of these components for the design is quite essential in terms of cost and performance (e.g., gain, power conversion effect [PCE]). For TLS, signal wavelength and power; for PDF, PDF length, ion density, upconversion, numerical aperture, core radius, doping radius, and operating environment temperature; pump laser, pump power, and pump wavelength are the critical design parameters. Another factor that will improve the performance of the amplifier is the amplifier configuration. Although there are single-pass and double-pass PDFA studies in the literature, in this article, for the first time, the simulation, parameter optimization, and analysis of two-stage triple-pass PDFA (2P3S-PDFA) and three-stage triple-pass PDFA (2P3S-PDFA) are performed. The performances of 2P3S-PDFA and 2P3S-PDFA are compared in terms of gain and noise figure (NF). The optimum gain obtained for 2S3P-PDFA is 49,4 dB, and the NF at this point is around 6,5 dB. For 3S3P-PDFA, the optimum gain is 47,7 dB and the NF at this point is around 5,1 dB. When we look at the two amplifier types in general, 2S3P-PDFA performs better than 3S3P-PDFA in terms of optimum gain by around 1,7 dB. However, in terms of NF, 2S3P-PDFA has more NF than 3S3P-PDFA by around 1,6 dB. As a result of the optimization, it is seen that the 2S3P-PDFA system is more efficient than the 3S3P-PDFA system in terms of gain.
{"title":"Performance evaluation of two-stage and three-stage triple pass PDFAs in O-band","authors":"Hasan Cihangir , Murat Yücel","doi":"10.1016/j.yofte.2025.104388","DOIUrl":"10.1016/j.yofte.2025.104388","url":null,"abstract":"<div><div>Tunable laser source (TLS), <span><math><msup><mrow><mi>P</mi><mi>r</mi></mrow><mrow><mn>3</mn><mo>+</mo></mrow></msup></math></span> doped fiber (PDF), and pump laser are the main design components for the praseodymium doped fiber amplifier (PDFA) design. Determination of the important parameter values of these components for the design is quite essential in terms of cost and performance (e.g., gain, power conversion effect [PCE]). For TLS, signal wavelength and power; for PDF, PDF length, ion density, upconversion, numerical aperture, core radius, doping radius, and operating environment temperature; pump laser, pump power, and pump wavelength are the critical design parameters. Another factor that will improve the performance of the amplifier is the amplifier configuration. Although there are single-pass and double-pass PDFA studies in the literature, in this article, for the first time, the simulation, parameter optimization, and analysis of two-stage triple-pass PDFA (2P3S-PDFA) and three-stage triple-pass PDFA (2P3S-PDFA) are performed. The performances of 2P3S-PDFA and 2P3S-PDFA are compared in terms of gain and noise figure (NF). The optimum gain obtained for 2S3P-PDFA is 49,4 dB, and the NF at this point is around 6,5 dB. For 3S3P-PDFA, the optimum gain is 47,7 dB and the NF at this point is around 5,1 dB. When we look at the two amplifier types in general, 2S3P-PDFA performs better than 3S3P-PDFA in terms of optimum gain by around 1,7 dB. However, in terms of NF, 2S3P-PDFA has more NF than 3S3P-PDFA by around 1,6 dB. As a result of the optimization, it is seen that the 2S3P-PDFA system is more efficient than the 3S3P-PDFA system in terms of gain.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"95 ","pages":"Article 104388"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145047188","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}
This study is devoted to the construction and investigation of a tunable random laser with a cavity based on weak fiber Bragg gratings (the so-called artificial Rayleigh fibers) inscribed in a 3-m-long active fiber. An array of weak fiber Bragg gratings (wFBGs) is inscribed using an ultraviolet (UV) excimer laser operating in pulsed mode and a chirped phase mask during the optical fiber drawing process. The inscription of a wFBG array by a UV laser is performed using a specially designed photosensitive germanophosphosilicate preform doped with erbium ions. It is found that, in a semi-open cavity configuration, the narrow-band generation peak can be tuned within the wavelength range of 1546.5–1547.5 nm by stretching the 90 %-reflective FBGs. The resulting random lasing is characterized by a maximum efficiency of 10 % at an output power of 1 mW under backward pumping at a wavelength of 976 nm. It is established that the tunable random laser operates in continuous-wave mode with a linewidth of ∼470 Hz.
{"title":"Tunable random laser with a cavity based on an erbium-doped germanophosphosilicate artificial Rayleigh fiber","authors":"S.M. Popov , A.A. Rybaltovsky , A.M. Smirnov , A.P. Bazakutsa , A.S. Shikin , D.V. Ryakhovskiy , V.V. Voloshin , A.O. Kolosovskii , I.L. Vorob’ev , Yu.K. Chamorovskiy , D.S. Lipatov , O.V. Butov","doi":"10.1016/j.yofte.2025.104405","DOIUrl":"10.1016/j.yofte.2025.104405","url":null,"abstract":"<div><div>This study is devoted to the construction and investigation of a tunable random laser with a cavity based on weak fiber Bragg gratings (the so-called artificial Rayleigh fibers) inscribed in a 3-m-long active fiber. An array of weak fiber Bragg gratings (wFBGs) is inscribed using an ultraviolet (UV) excimer laser operating in pulsed mode and a chirped phase mask during the optical fiber drawing process. The inscription of a wFBG array by a UV laser is performed using a specially designed photosensitive germanophosphosilicate preform doped with erbium ions. It is found that, in a semi-open cavity configuration, the narrow-band generation peak can be tuned within the wavelength range of 1546.5–1547.5 nm by stretching the 90 %-reflective FBGs. The resulting random lasing is characterized by a maximum efficiency of 10 % at an output power of 1 mW under backward pumping at a wavelength of 976 nm. It is established that the tunable random laser operates in continuous-wave mode with a linewidth of ∼470 Hz.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"95 ","pages":"Article 104405"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145047191","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 : 2025-12-01Epub Date: 2025-10-24DOI: 10.1016/j.yofte.2025.104458
Kuan-Yi Wu, Der-Rong Din
Filterless optical networks (FONs) are attractive due to their cost and energy efficiency; however, multicast provisioning under edge-disjointness can intensify spectrum contention. This work investigates the joint design of multilevel edge-disjoint multicast trees and spectrum assignment that minimizes the maximum number of frequency slots, subject to a physical topology and a traffic-demand matrix, while adhering to a maximum reach constraint. We develop single-level and multilevel algorithms, including heuristics seeded by minimum-spanning and shortest-path trees, as well as genetic-algorithm (GA) variants that jointly optimize tree construction and demand-to-tree assignment. Simulations show that the GA consistently reduces peak spectrum usage relative to heuristics. At the same time, multilevel designs further lower the peak compared with single-level counterparts. We also observe that a simple demand-allocation rule — assigning to the minimum-edge tree first — performs robustly across networks. The results indicate that GA-guided, multilevel designs offer a practical and scalable approach to multicast provisioning in FONs.
{"title":"Planning of multilevel edge-disjoint trees in filterless optical networks","authors":"Kuan-Yi Wu, Der-Rong Din","doi":"10.1016/j.yofte.2025.104458","DOIUrl":"10.1016/j.yofte.2025.104458","url":null,"abstract":"<div><div>Filterless optical networks (FONs) are attractive due to their cost and energy efficiency; however, multicast provisioning under edge-disjointness can intensify spectrum contention. This work investigates the joint design of multilevel edge-disjoint multicast trees and spectrum assignment that minimizes the maximum number of frequency slots, subject to a physical topology and a traffic-demand matrix, while adhering to a maximum reach constraint. We develop single-level and multilevel algorithms, including heuristics seeded by minimum-spanning and shortest-path trees, as well as genetic-algorithm (GA) variants that jointly optimize tree construction and demand-to-tree assignment. Simulations show that the GA consistently reduces peak spectrum usage relative to heuristics. At the same time, multilevel designs further lower the peak compared with single-level counterparts. We also observe that a simple demand-allocation rule — assigning to the minimum-edge tree first — performs robustly across networks. The results indicate that GA-guided, multilevel designs offer a practical and scalable approach to multicast provisioning in FONs.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"95 ","pages":"Article 104458"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145362982","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}
We propose and study a novel method for measuring the chromatic dispersion parameter (D) of optical fibers by means of a single-arm three-wave interferometer (SAI) and a fiber femtosecond frequency comb (FFFC). The FFFC is frequency locked to a single-ytterbium-ion optical standard and employed as a source of highly stable and broadband laser radiation. The FFFC spectrum ranges from 1 to 2 μm, which is the most demanded range in fiber optics. The theoretical model developed in the work is used to derive simple analytical expressions for the parameter D, taking into account the dispersion slope (DS). To verify the method, the parameter D is measured for a standard single-mode SMF-28 fiber with a length of 1.23 m. At a wavelength of 1550 nm, the value of D has been found to be approximately 16.6 ps/(nm∙km) with taking into account the DS. The root mean square error of measurements is 0.86 ps/(nm∙km). Another key feature of the method is that it enables accurate measurements of the parameter D across a broad spectral range in a relatively short time. All these features make the proposed method very attractive for a wide scope of applications in fiber-optic technology.
{"title":"Fast, accurate and simple method for measuring the chromatic dispersion of optical fibers using a single-arm interferometer and a frequency comb","authors":"N.A. Koliada , D.V. Brazhnikov , A.A. Filonov , Y.G. Isaeva , V.S. Pivtsov","doi":"10.1016/j.yofte.2025.104402","DOIUrl":"10.1016/j.yofte.2025.104402","url":null,"abstract":"<div><div>We propose and study a novel method for measuring the chromatic dispersion parameter (<em>D</em>) of optical fibers by means of a single-arm three-wave interferometer (SAI) and a fiber femtosecond frequency comb (FFFC). The FFFC is frequency locked to a single-ytterbium-ion optical standard and employed as a source of highly stable and broadband laser radiation. The FFFC spectrum ranges from 1 to 2 μm, which is the most demanded range in fiber optics. The theoretical model developed in the work is used to derive simple analytical expressions for the parameter <em>D</em>, taking into account the dispersion slope (DS). To verify the method, the parameter <em>D</em> is measured for a standard single-mode SMF-28 fiber with a length of 1.23 m. At a wavelength of 1550 nm, the value of <em>D</em> has been found to be approximately 16.6 ps/(nm∙km) with taking into account the DS. The root mean square error of measurements is 0.86 ps/(nm∙km). Another key feature of the method is that it enables accurate measurements of the parameter <em>D</em> across a broad spectral range in a relatively short time. All these features make the proposed method very attractive for a wide scope of applications in fiber-optic technology.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"95 ","pages":"Article 104402"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097024","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}
This study investigates the spatial disturbance and diffusion pathways of deep reinjection reservoirs for high-salinity mine water. Taking a coal mine in Yushenfu as a case study, a 3D physical model (240 cm × 180 cm × 150 cm) was constructed and integrated with a distributed optical fiber sensing system. Optical Frequency Domain Reflectometry (OFDR) technology was employed to achieve high-precise monitoring of reservoir deformation. Concurrently, a numerical model was established in COMSOL Multiphysics to analyze the coupling between mine water diffusion and reservoir mechanics during reinjection, allowing comparison with the physical experiment. The results indicate that the physical model and numerical simulation have a good consistency. The OFDR technology effectively captured spatial disturbance caused by reinjection, with fiber strain curves delineating the extent and pathways of water migration. The reinjection process follows three stages: pore/fracture filling, hydraulic channel expansion, and sequestration pressure disturbance. OFDR strain monitoring exhibits excellent spatial resolution and measurement accuracy, making it highly suitable for physical modeling applications. Overall, this approach provides an effective means for evaluating the sequestration performance and optimizing the reinjection process in deep mine water reinjection systems.
研究了深部高矿化度矿井水回注储层的空间扰动和扩散路径。以玉神府某煤矿为例，构建了240 cm × 180 cm × 150 cm的三维物理模型，并与分布式光纤传感系统集成。利用光学频域反射技术（OFDR）实现了储层变形的高精度监测。同时，在COMSOL Multiphysics中建立数值模型，分析回注过程中矿井水扩散与储层力学的耦合关系，并与物理实验进行对比。结果表明，物理模型与数值模拟具有较好的一致性。OFDR技术有效捕获了回注引起的空间扰动，纤维应变曲线描绘了水运移的程度和途径。回注过程分为孔隙/裂缝填充、水力通道扩张和封存压力扰动三个阶段。OFDR应变监测具有优异的空间分辨率和测量精度，非常适合物理建模应用。综上所述，该方法为评价深井回注系统的封存性能和优化回注工艺提供了有效手段。
{"title":"Study on spatial disturbance characteristics in deep reinjection reservoirs for high-salinity mine water","authors":"Yali Peng , Shiang Xu , Pingsong Zhang , Jiankun Xue , Haibo Wu , Yucan Xiong","doi":"10.1016/j.yofte.2025.104399","DOIUrl":"10.1016/j.yofte.2025.104399","url":null,"abstract":"<div><div>This study investigates the spatial disturbance and diffusion pathways of deep reinjection reservoirs for high-salinity mine water. Taking a coal mine in Yushenfu as a case study, a 3D physical model (240 cm × 180 cm × 150 cm) was constructed and integrated with a distributed optical fiber sensing system. Optical Frequency Domain Reflectometry (OFDR) technology was employed to achieve high-precise monitoring of reservoir deformation. Concurrently, a numerical model was established in COMSOL Multiphysics to analyze the coupling between mine water diffusion and reservoir mechanics during reinjection, allowing comparison with the physical experiment. The results indicate that the physical model and numerical simulation have a good consistency. The OFDR technology effectively captured spatial disturbance caused by reinjection, with fiber strain curves delineating the extent and pathways of water migration. The reinjection process follows three stages: pore/fracture filling, hydraulic channel expansion, and sequestration pressure disturbance. OFDR strain monitoring exhibits excellent spatial resolution and measurement accuracy, making it highly suitable for physical modeling applications. Overall, this approach provides an effective means for evaluating the sequestration performance and optimizing the reinjection process in deep mine water reinjection systems.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"95 ","pages":"Article 104399"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097023","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 : 2025-12-01Epub Date: 2025-09-08DOI: 10.1016/j.yofte.2025.104396
Monica T. Kalichevsky-Dong, Samuel P. Bingham, Thomas W. Hawkins, Jannatul M. Nijhum, Liang Dong
Diffraction-limited 308 W at ∼980 nm from a monolithic ytterbium fiber laser operating at the three-level laser system has been demonstrated, limited only by the available pump power, doubling the previous record and showing significant potential for further power scaling thanks to the availability of high brightness pumps and ytterbium-doped all-solid photonic bandgap fibers optimized for suppressing the four-level system. New record slope efficiencies of 72 % and 81 % for three-level lasers with regard to launched and absorbed pump powers respectively are also set.
{"title":"Diffraction-limited 308 W at ∼980 nm from a monolithic ytterbium fiber laser","authors":"Monica T. Kalichevsky-Dong, Samuel P. Bingham, Thomas W. Hawkins, Jannatul M. Nijhum, Liang Dong","doi":"10.1016/j.yofte.2025.104396","DOIUrl":"10.1016/j.yofte.2025.104396","url":null,"abstract":"<div><div>Diffraction-limited 308 W at ∼980 nm from a monolithic ytterbium fiber laser operating at the three-level laser system has been demonstrated, limited only by the available pump power, doubling the previous record and showing significant potential for further power scaling thanks to the availability of high brightness pumps and ytterbium-doped all-solid photonic bandgap fibers optimized for suppressing the four-level system. New record slope efficiencies of 72 % and 81 % for three-level lasers with regard to launched and absorbed pump powers respectively are also set.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":"95 ","pages":"Article 104396"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145011173","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 : 2025-12-01Epub Date: 2025-10-17DOI: 10.1016/j.yofte.2025.104444
Sajjad Zare , Ahmad Khonsari , Akbar Ghaffarpour Rahbar , Masoumeh Moradian
Data traffic demand is increasing every year, and networks must respond to these increasing demands. On the other hand, Wavelength Division Multiplexing (WDM) networks, due to their static allocation, waste resources and are unable to meet the necessary requirements. To solve this problem, Elastic Optical Networks (EONs) with dynamic spectrum allocation have been developed, and it has been shown that EONs can enhance resource utilization relative to WDM-based networks. The main challenge in EONs is efficiently allocating resources to optimize network capacity utilization. On the one hand, Dynamic spectrum assignment and diverse available schemes for demands lead to higher spectrum utilization. Multicasting, also known as multi-destination data transfer, is one of the most cost-effective and efficient techniques for providing flow in computer networks, a technology attracting considerable attention due to the widespread adoption of internet-based services. This paper introduces a novel RL-driven framework for multi-objective cost optimization in dynamic multicast routing. We propose two algorithms: MIN (Multicasting through Intermediate Nodes) and MIN2P (via 2 Paths), which integrate hop count, physical distance, and frequency slot congestion into a unified cost function. MIN leverages intermediate nodes (destination and non-destination) via SPT algorithm for logical tree construction, while MIN2P enhances load balancing by splitting traffic across two paths with first-fit and last-fit spectrum allocation. For the first time, a Q-learning-based reinforcement learning (RL) agent adaptively tunes the cost function weights in real-time, responding to network conditions to minimize blocking probability. Simulations on NSFNET and JPN12 topologies, with varying traffic loads (100–800 Gbps), demonstrate that hop count is the most influential metric, reducing blocking rates by up to 30% compared to benchmarks like OL-M-SFMOR and MT3A. MIN excels in low-congestion scenarios, while MIN2P outperforms in high-load, large topologies due to effective load distribution. This framework provides actionable insights for designing adaptive, efficient EONs, advancing multicast capabilities in next-generation optical networks.
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