Optical Fiber Technology最新文献

{"title":"MLGO: A machine learning-based mountain gazelle optimization algorithm for efficient resource management and load balancing in fiber wireless access networks","authors":"Mausmi Verma ,&nbsp;Uma Rathore Bhatt ,&nbsp;Raksha Upadhyay ,&nbsp;Vijay Bhat","doi":"10.1016/j.yofte.2024.104014","DOIUrl":"10.1016/j.yofte.2024.104014","url":null,"abstract":"<div><div>Addressing the challenges posed by escalating data demands, connected devices, and bandwidth-hungry technologies, Fiber Wireless (FiWi) networks offer a holistic solution. Nevertheless, among the most significant challenges faced by FiWi networks are the component deployment, its connectivity, and performance under varying loads. In the FiWi network the ONUs plays a pivotal role in collecting and forwarding wireless-generated traffic thereby emphasizing the need for efficient resource management to ensure network reliability. Overloading of ONU often results in network congestion, as ONU serves as an intermediatory node between optical backend and wireless frontend. Thus, traffic offloading is a great solution by identifying underloaded ONUs and redirecting a portion of the excess traffic from overloaded ONUs to underloaded ONUs to maintain balanced resource allocation. However, identification of wireless routers within the wireless frontend is a crucial step, enabling strategic decision-making in rerouting traffic and promoting load balancing. Thus, the proposed work suggests a new hybrid two step method termed as MLGO (Machine learning based Mountain Gazelle Optimization Algorithm) which first uses machine learning based k-means clustering algorithm for nodes (Wireless routers and ONU) placement and connectivity and the second step employs the Mountain Gazelle Optimization algorithm (MGO) and GA for identifying optimum wireless routers for traffic offloading which enhances the overall FiWi network performance. The paper contributes to the evolution of FiWi networks, ensuring optimal connectivity, efficient resource utilization, and enhanced packet delivery ratio for end-users. Simulation results validate the effectiveness of this two-step proposed approach.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587188","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":"Mode coupling at an imperfect Fresnel surface in a fluorine-trench dual-mode fiber","authors":"Xiaolu Cao ,&nbsp;Mingming Luo ,&nbsp;Jianfei Liu ,&nbsp;Jie Ma","doi":"10.1016/j.yofte.2024.104027","DOIUrl":"10.1016/j.yofte.2024.104027","url":null,"abstract":"<div><div>Mode coupling, often overlooked at an imperfect Fresnel surface, is now examined in a fluorine-trench dual-mode fiber to avoid energy losses and signal degradation. For invisible defects on the reflecting surface, the orthogonal forward LP₀₁ (LP₁₁) mode with group velocity <em>v</em>_g^LP₀₁ (<em>v</em>_g^LP₁₁) partially converts to the backward LP₁₁ (LP₀₁) mode with <em>v</em>_g^LP₁₁ (<em>v</em>_g^LP₀₁) through a transfer matrix, respectively. Consequently, this interaction generates a unique hybrid backward mode, which results in an average round-trip time delay and the mean of the velocities, (<em>v</em>_g^LP₀₁ + <em>v</em>_g^LP₁₁)/2. Upon harvesting and analyzing the backward reflections using a high-resolution coherent optical frequency domain reflectometry, a Fresnel reflection peak corresponding to the hybrid mode is observed with a high signal-to-noise ratio precisely between the LP₀₁ and LP₁₁ peaks. Additionally, the frequency difference between the hybrid and LP₀₁ (or LP₁₁) modes is calculated to be 20.625 Hz exactly half of the 41.250 Hz difference between the LP₀₁ and LP₁₁ modes. Further testing on five additional fiber segments ranging from 8.812 m to 10.812 m corroborates this theory, as their <em>v</em>_g^hybrid values align closely with (<em>v</em>_g^LP₀₁ + <em>v</em>_g^LP₁₁)/2. Our analytical insights detail the dynamic mode coupling at an imperfect Fresnel surface, promising a flexible method for dynamic mode observation and regulation for mode division multiplexing optical fiber communications, particularly in enhancing the detection and mitigation of defects at fiber lasing end faces.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587187","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":"Optimization of a wideband discrete Raman amplifier in a P2O5-doped optical fiber using multi-objective grey wolf algorithm","authors":"Luís C.B. Silva,&nbsp;Helder R.O. Rocha,&nbsp;Marcelo E.V. Segatto,&nbsp;Carlos E.S. Castellani","doi":"10.1016/j.yofte.2024.104023","DOIUrl":"10.1016/j.yofte.2024.104023","url":null,"abstract":"<div><div>This paper demonstrates the use of the multi-objective grey wolf algorithm to optimize a discrete Raman amplifier (DRA) in a P₂O₅-doped optical fiber. Specifically, the multi-objective grey wolf algorithm is combined with the DRA to carry out a process that seeks to maximize the gain and minimize the ripple. The P₂O₅-doped optical fiber employed in this study has a Raman gain coefficient spectrum with multiple peaks with different frequency shifts. This allows them to be combined in more complex ways than optical fibers with a single peak in the Raman gain spectrum. Consequently, the gain curve produced with this fiber has the potential to be more adjustable even when fewer pumps are used. Thus, this paper explores this fact to perform, to the best of our knowledge, the first specialized optimization process reported in the scientific literature of a wideband discrete Raman amplifier in a P₂O₅-doped optical fiber. With a different gain profile of this fiber compared to those of traditional standard optical fibers, it was possible to design a wideband DRA, going from 1530 nm to 1675 nm, covering C+L+U bands, maintaining a ripple of up to 8 dB with a net gain of 14 dB using only 3 pumps. Moreover, this work demonstrates for the first time, through a comparative analysis, that the multi-objective grey wolf algorithm performs better than the standard and well-known non-dominated sorting genetic optimization algorithm to optimize a DRA in a P₂O₅-doped optical fiber. The proposed DRA is a feasible, low-cost, and simple alternative for building fiber amplifiers for future high-bandwidth and wideband wavelength division multiplexing (WDM) communication systems, network infrastructures such as data centers, undersea cables, 5G and beyond, and cutting-edge research applications.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586702","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":"Power over fiber system using high-power laser source operating at 1470 nm with maximum power 2.0 W for powering to distance up to 5855 m","authors":"Vaclav Prajzler,&nbsp;Marek Zikmund","doi":"10.1016/j.yofte.2024.104033","DOIUrl":"10.1016/j.yofte.2024.104033","url":null,"abstract":"<div><div>We report on the properties of the Power over Fiber (PoF) system using a High-Power Laser Source (HPLS) operating at 1470 nm with an optical power of up to 2.0 W. Graded-index and step-index optical fibers with a core diameter of 50 µm were used for transmission and two types of Photovoltaic Power Converters (PPCs) were used for optical power to electricity conversion. We experimentally demonstrated the powering to a distance of 5855 m, where we achieved the electric power of 44.4 mW and estimated the possibility of powering to distances longer than 9000 m with the input optical power of 15 W, where we expect to achieve the delivery of the electric power around 150 mW.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571648","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":"Enhancing high-order harmonic mode-locking in Er/Yb-Doped fiber lasers with sub-MHz fundamental frequency via optoacoustic resonance","authors":"Alexander Sudin ,&nbsp;Igor Volkov ,&nbsp;Sergey Ushakov ,&nbsp;Konstantin Nishchev ,&nbsp;Dmitry Korobko ,&nbsp;Andrei Fotiadi","doi":"10.1016/j.yofte.2024.104028","DOIUrl":"10.1016/j.yofte.2024.104028","url":null,"abstract":"<div><div>We present an experimental study of a long Er/Yb-doped fiber ring laser with a low fundamental frequency of 0.678 MHz. By solely adjusting the quarter-wave plate in the polarization controller, we uncovered a series of reproducible laser generation regimes. Among these, multiple soliton bunches were harmonically mode-locked to low-order cavity harmonics (from the 3rd to the 8th). Notably, we also identified a regime featuring a stable soliton train harmonically mode-locked to the 472nd cavity harmonic at 320 MHz. This regime demonstrated exceptional harmonic mode-locking stability, with a supermode suppression level of 49 dB corresponding to the timing jitter on the order of a few picoseconds. We attribute this remarkable stability to an exact optoacoustic resonance between the laser repetition rate and the fiber eigen acoustic mode frequencies, specifically identified as R₀₆ and TR₂,₁₅. These findings represent a significant advancement in high-performance fiber laser operation, particularly in enhancing the stability of lasers with sub-MHz fundamental frequencies capable to generate regular pulses with much higher repetition rates.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572177","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":"Experimental analysis of optical spectrum based power distribution analysis for intermediate node monitoring in optical networks using shallow multi-task artificial neural network","authors":"Sindhumitha Kulandaivel,&nbsp;R.K. Jeyachitra","doi":"10.1016/j.yofte.2024.104013","DOIUrl":"10.1016/j.yofte.2024.104013","url":null,"abstract":"<div><div>In this work, we propose an intelligent solution to cost-effective intermediate node monitoring in optical networks using optical spectrum-based power distribution analysis (OSPDA) and shallow multi-task artificial neural network (SMT-ANN). The proposed technique is used to realize simultaneous identification of modulation format (MF) and multi-parameter optical performance monitoring (OPM) such as identification of launch power (LP), chromatic dispersion (CD), differential group delay (DGD), and optical signal-to-noise ratio (OSNR) estimation. OSPDA is based on comparing optical spectrums with and without impairment to determine the power level deviations and correlation for simultaneous OPM. It involves features derived from OSPDA as input to the proposed SMT-ANN for executing both identification and estimation of OPM. The experimental validation has been carried out for 10 different MFs such as 4 Quadrature Amplitude Modulation (QAM), 8 QAM, 16 QAM, 32 QAM, 64 QAM, Binary Phase Shift Keying (BPSK), Quadrature Phase Shift Keying (QPSK), Offset QPSK (OQPSK), 8 Phase Shift Keying (PSK), and 16 PSK at three LP for both back-to-back (B2B) and 50 km optical fiber transmission link. The various levels of CD and DGD were introduced using different lengths of optical fiber. The best results achieved from the analysis include 99.87 %, 99.81 %, 98.72 %, and 98.36 % identification accuracy for MF, LP, CD, and DGD respectively. The minimum average mean absolute error (MAE) obtained for OSNR estimation is 0.218 dB. Thus, the proposed method is practically feasible for simultaneous OPM at intermediate nodes for real-time robust and reconfigurable optical networks.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572176","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":"Single-longitudinal-mode thulium-doped fiber laser based on the composite filtering effect of multiple types narrow-bandwidth filters","authors":"Tongyu Dai ,&nbsp;Ying Chen ,&nbsp;Jiaze Wu ,&nbsp;Jiawei Fan ,&nbsp;Yuechu Wu ,&nbsp;Chenchen Jiang ,&nbsp;Ye Zhang ,&nbsp;Chunting Wu ,&nbsp;Yongji Yu ,&nbsp;Baoquan Yao ,&nbsp;Youlun Ju ,&nbsp;Jing Zhang","doi":"10.1016/j.yofte.2024.104021","DOIUrl":"10.1016/j.yofte.2024.104021","url":null,"abstract":"<div><div>We demonstrate a single-longitudinal-mode thulium-doped fiber laser operating at 1.94 μm. Stable single-longitudinal mode operation is contingent upon the synergistic filtering effect of multiple narrow-bandwidth filters of varying types. By inserting dynamic Bragg grating with unpumped thulium-doped fiber, fiber Bragg grating and sub-ring filters into the thulium-doped laser cavity to enhance longitudinal mode selection capability, the maximum single-longitudinal-mode laser power reaches 544 mW. The time-domain root mean square (RMS) value of laser power is calculated to be 0.41 %. The wavelength tuning from 1940.02 to 1941.12 nm is also demonstrated by varying the temperature of the Fiber Bragg Grating.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552094","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":"Saturable absorption in erbium-doped fiber for controlling lasing peaks and their linewidths in fiber laser","authors":"Deeksha Jachpure ,&nbsp;Om Prakash ,&nbsp;R. Vijaya","doi":"10.1016/j.yofte.2024.104022","DOIUrl":"10.1016/j.yofte.2024.104022","url":null,"abstract":"<div><div>A standard erbium-doped fiber ring laser is constructed and studied for its lasing features. An additional length of unpumped erbium-doped fiber inserted in the ring cavity increases the cavity loss as well as the cavity length, and decides the new central wavelength of lasing. Under optimum conditions, the saturable absorption effect in the added length of unpumped erbium-doped fiber introduces more loss for the longitudinal modes of lower power while leaving the longitudinal modes of higher power undisturbed, thus narrowing the laser linewidth. The reduction in the 3 dB linewidth of the lasing peak from 0.170 nm to 0.070 nm is demonstrated using an additional unpumped erbium-doped fiber length of 85 cm at a low pump power of 60 mW. As a result of this reduction in linewidth, the quality factor increases from 9.2 x 10³ to 2.2 x 10⁴ and the number of longitudinal modes reduces from ∼ 1400 to ∼ 580 within the central lasing peak. The distinct reduction of spectral width and the consequent increase in the quality factor of the laser output are brought out through the experimental data. Unlike a linear loss element introduced in the ring cavity, the narrowing of linewidth due to the saturable absorber is not accompanied with a loss of power at the central wavelength. In addition, it is found to be dependent on the location where the saturable absorber is present in the ring cavity, thus emphasizing the role of selective absorption in the ring cavity.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554010","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 force sensor based on FPI for flexible needle force sensing","authors":"Lihui Yu,&nbsp;Qi Jiang,&nbsp;Feiwen Wang","doi":"10.1016/j.yofte.2024.104012","DOIUrl":"10.1016/j.yofte.2024.104012","url":null,"abstract":"<div><div>In order to solve the problems of puncture force sensing error and delay during the puncturing of human tissue by flexible needle, a Fabry–Perot (FPI) sensor consisting of single-mode optical fibre and air cavity is proposed. The FPI was fixed to the tip of a flexible needle and puncture experiments were carried out on four different hardnesses of silicone. The experimental results show that the sensor not only has high resolution and sensitivity of the puncture force, which can effectively sense the small change of the cutting force during the puncture process, but also has a smaller time delay compared with the commercial force sensor, which can sense the change of the puncture force during the puncture process in time.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554011","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":"Monitoring optogenetic stimulation of light-sensitive stem cells using a twin-core fiber-based Mach-Zehnder interferometer","authors":"Faezeh Akbari ,&nbsp;Mohammad Ismail Zibaii ,&nbsp;Sara Chavoshinezhad ,&nbsp;Azam Layeghi ,&nbsp;Leila Dargahi ,&nbsp;Orlando Frazao","doi":"10.1016/j.yofte.2024.104024","DOIUrl":"10.1016/j.yofte.2024.104024","url":null,"abstract":"<div><div>The application of optical fibers in optogenetics is rapidly expanding due to their compactness, cost-effectiveness, sensitivity, and accuracy. This paper introduces a twin-core optical fiber (TCF) sensor employing a Mach-Zehnder interferometer (MZI) to monitor the optogenetic response of opsin-expressing human dental pulp stem cells (hDPSCs) based on refractive index (RI) measuring. In order to improve the RI sensitivity of the sensor, an in-fiber Mach-Zeander modulator formed using TCF optics segments can detect changes in the RI in the surrounding medium, and in order to improve the RI sensitivity of the sensor, it is proposed to etch one side of the TCF cladding. The RI sensitivity of the sensor was obtained 233.62 nm/RIU in the range of 1.33–1.4 RIU and 870.01 nm/RIU in the range of 1.4–1.43 RIU, R² = 0.99. simulation results show that in terms of sensor sensitivity and spectral response, there is a good agreement between the theoretical and experimental results, indicating that the TCF-MZI sensor can perform optical neural recording. In vitro experiments monitored wavelength changes in opsin-expressing and non-opsin-expressing in human dental pulp stem cells (hDPSCs) during optogenetic stimulation with 473 nm pulsed illumination. The results revealed that optical stimulation of ChR2 opsin-expressing hDPSCs leads to active the light sensitive ion channel and changing the effective RI of the surrounding medium. The neural activity is driven by changes in intracellular and extracellular ion concentrations, which lead to alterations in the RI of the cell medium RI variations detectable by the sensor. The novel sensor structure demonstrated its ability to detect RI changes in the cell medium during optogenetic stimulation and fiber optic sensors can be a good candidate for optical recording of the neural activity. Beyond these in vivo applications, label free fiber optic biosensors-based IR measurement can be used for all optical multifunctional probe in stimulation, recording, and sensing of neuroscience applications.</div></div>","PeriodicalId":19663,"journal":{"name":"Optical Fiber Technology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554130","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}