This paper presents a PDMS-polymer based flexible diffractive optical element (DOE) for tunable beam shaping, which combine the mechanical adaptability of PDMS with the precise micro-structure formation enabled by polymer patterning. A PDMS-polymer based flexible tunable DOE is described and designed. And a detailed fabrication technology is provided for the designed DOE. The experimental results show that the fabricated flexible DOE can shape a Gaussian beam to rectangular beam. The shaped rectangular beam can be tuned by applying mechanical strain, which can introduce 0∼−32.21% length and 0∼+12.31% width variation by applying 0∼70% mechanical strain in horizontal direction, and 0∼+22.81% length and 0∼−30.97% width variation by applying 0∼70% mechanical strain in longitudinal direction. The changes in CV and diffractive efficiency of the shaped beam during this process are within an acceptable range of less than 12%. Fatigue resistance test also demonstrated that the proposed flexible DOE exhibited stable tunable performance during 500 times strain-restore, indicating excellent durability with the CV change less than 6% and diffractive efficiency change less than 2%. This approach provides a cost-effective and practical solution for dynamic beam shaping applications.
{"title":"A PDMS-Polymer Based Flexible DOE for Tunable Beam Shaping","authors":"Bowen Niu;Yanjun Hu;Qun Dai;Yu Ao;Yu Qiao;Xuanwei Xu;Xiaoyu Cai;Jiasi Wei;Yuan Li;Guofang Fan","doi":"10.1109/JLT.2025.3630640","DOIUrl":"https://doi.org/10.1109/JLT.2025.3630640","url":null,"abstract":"This paper presents a PDMS-polymer based flexible diffractive optical element (DOE) for tunable beam shaping, which combine the mechanical adaptability of PDMS with the precise micro-structure formation enabled by polymer patterning. A PDMS-polymer based flexible tunable DOE is described and designed. And a detailed fabrication technology is provided for the designed DOE. The experimental results show that the fabricated flexible DOE can shape a Gaussian beam to rectangular beam. The shaped rectangular beam can be tuned by applying mechanical strain, which can introduce 0∼−32.21% length and 0∼+12.31% width variation by applying 0∼70% mechanical strain in horizontal direction, and 0∼+22.81% length and 0∼−30.97% width variation by applying 0∼70% mechanical strain in longitudinal direction. The changes in CV and diffractive efficiency of the shaped beam during this process are within an acceptable range of less than 12%. Fatigue resistance test also demonstrated that the proposed flexible DOE exhibited stable tunable performance during 500 times strain-restore, indicating excellent durability with the CV change less than 6% and diffractive efficiency change less than 2%. This approach provides a cost-effective and practical solution for dynamic beam shaping applications.","PeriodicalId":16144,"journal":{"name":"Journal of Lightwave Technology","volume":"44 2","pages":"634-643"},"PeriodicalIF":4.8,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-10DOI: 10.1109/JLT.2025.3630609
Yongsen Zhao;Baole Lu;Yi Yan;Chenyue Lv;Yongkang Wang;Mei Qi;Jintao Bai
Harmonic mode locking (HML) is an effective technique for generating optical pulses with high repetition rates. However, its signal-to-noise ratio (SNR) is typically limited under high-order states, hindering practical applications. In this study, we successfully generated high-SNR (>70 dB) HML pulses in an all-polarization-maintaining erbium-doped fiber laser by employing a hybrid mode-locking mechanism combining nonlinear polarization evolution (NPE) and a semiconductor saturable absorber mirror (SESAM). This approach leverages NPE's ability to stably generate high-order harmonics alongside SESAM's low mode-locking threshold. The all-polarization-maintaining design ensures environmental stability. Adjusting the pump power (120-630 mW) enables multi-order HML transitions spanning 112.86 MHz to 1.24 GHz. The 121st harmonic is the highest harmonic we have achieved so far. Even when the repetition frequency exceeds GHz and the harmonic order is over 100, it still achieves an ultra-high signal-to-noise ratio of 83.03 dB. This study provides a practical, novel solution for developing cost-effective, integrable, GHz-class ultrashort pulse sources with high SNR.
{"title":"High Signal-to-Noise Ratio GHz Harmonic Pulse Implementation Based on All Polarization-Maintaining Hybrid Mode-Locked Fiber Laser","authors":"Yongsen Zhao;Baole Lu;Yi Yan;Chenyue Lv;Yongkang Wang;Mei Qi;Jintao Bai","doi":"10.1109/JLT.2025.3630609","DOIUrl":"https://doi.org/10.1109/JLT.2025.3630609","url":null,"abstract":"Harmonic mode locking (HML) is an effective technique for generating optical pulses with high repetition rates. However, its signal-to-noise ratio (SNR) is typically limited under high-order states, hindering practical applications. In this study, we successfully generated high-SNR (>70 dB) HML pulses in an all-polarization-maintaining erbium-doped fiber laser by employing a hybrid mode-locking mechanism combining nonlinear polarization evolution (NPE) and a semiconductor saturable absorber mirror (SESAM). This approach leverages NPE's ability to stably generate high-order harmonics alongside SESAM's low mode-locking threshold. The all-polarization-maintaining design ensures environmental stability. Adjusting the pump power (120-630 mW) enables multi-order HML transitions spanning 112.86 MHz to 1.24 GHz. The 121st harmonic is the highest harmonic we have achieved so far. Even when the repetition frequency exceeds GHz and the harmonic order is over 100, it still achieves an ultra-high signal-to-noise ratio of 83.03 dB. This study provides a practical, novel solution for developing cost-effective, integrable, GHz-class ultrashort pulse sources with high SNR.","PeriodicalId":16144,"journal":{"name":"Journal of Lightwave Technology","volume":"44 2","pages":"689-695"},"PeriodicalIF":4.8,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-06DOI: 10.1109/JLT.2025.3630006
Cong Zhang;Yu Zhen;Xinghuan Wu;Jianping Li;Yuwen Qin;Songnian Fu
Nested anti-resonant nodeless fiber (NANF) fusion splicing with variable structural parameters is essential yet challenging for both hollow-core fiber (HCF) research and field deployment. Here, we comprehensively investigate the impact of structural parameter variations on the mode field diameter (MFD) and corresponding NANF splicing performance. Numerical simulation results indicate that the air core diameter is the dominant factor in determining the MFD of NANF, and the MFD is approximately 70% of the air core diameter. Variations of the other structure parameters hold a negligible impact on the MFD. Numerical evaluation of splicing performance reveals that, under the condition of a fixed air core diameter, splicing between NANFs with different numbers of nested tube units (e.g., 5-tube and 6-tube NANF), introduces an intrinsic coupling loss (ICL) of ∼0.045 dB, attributed to the mode field shape mismatch rather than the angular alignment, as the ICL does not vary periodically with the rotational angle. Meanwhile, variations of the other parameters contribute less than 0.01 dB ICL. Finally, we conduct an experimental evaluation of fusion splicing performance by fabricating four types of NANFs with varying nested tube units, inner tube diameters, and nested tube layers. We characterize the angle alignment sensitivity, high-order mode excitation, and back-reflection performance when various combinations of four types of NANFs are fusion-spliced. Those results of NANF fusion splicing provide valuable insights for the standardization and flexible field deployment.
可变结构参数的嵌套抗谐振无节点光纤（NANF）融合拼接对于空心光纤（HCF）的研究和现场部署都是必不可少的，但也是具有挑战性的。在这里，我们全面研究了结构参数变化对模场直径（MFD）和相应的NANF拼接性能的影响。数值模拟结果表明，空气芯直径是决定纳米材料最大流通量的主要因素，最大流通量约占空气芯直径的70%。其他结构参数的变化对MFD的影响可以忽略不计。拼接性能的数值评估表明，在固定空气芯直径的条件下，具有不同嵌套管单元数量的NANF（例如，5管和6管NANF）之间的拼接引入了固有耦合损失（ICL）约0.045 dB，这归因于模式场形状不匹配而不是角对准，因为ICL不随旋转角度周期性变化。同时，其他参数的变化贡献小于0.01 dB ICL。最后，我们通过制作四种不同嵌套管单元、内管直径和嵌套管层的纳米材料，对融合拼接性能进行了实验评估。我们描述了四种类型的纳米纳米材料在不同组合融合拼接时的角度对准灵敏度、高阶模式激发和背反射性能。NANF融合拼接的结果为标准化和灵活的现场部署提供了有价值的见解。
{"title":"Fusion Splicing Performance Evaluation of Hollow-Core Fiber to Hollow-Core Fiber With Different Structural Parameters","authors":"Cong Zhang;Yu Zhen;Xinghuan Wu;Jianping Li;Yuwen Qin;Songnian Fu","doi":"10.1109/JLT.2025.3630006","DOIUrl":"https://doi.org/10.1109/JLT.2025.3630006","url":null,"abstract":"Nested anti-resonant nodeless fiber (NANF) fusion splicing with variable structural parameters is essential yet challenging for both hollow-core fiber (HCF) research and field deployment. Here, we comprehensively investigate the impact of structural parameter variations on the mode field diameter (MFD) and corresponding NANF splicing performance. Numerical simulation results indicate that the air core diameter is the dominant factor in determining the MFD of NANF, and the MFD is approximately 70% of the air core diameter. Variations of the other structure parameters hold a negligible impact on the MFD. Numerical evaluation of splicing performance reveals that, under the condition of a fixed air core diameter, splicing between NANFs with different numbers of nested tube units (e.g., 5-tube and 6-tube NANF), introduces an intrinsic coupling loss (ICL) of ∼0.045 dB, attributed to the mode field shape mismatch rather than the angular alignment, as the ICL does not vary periodically with the rotational angle. Meanwhile, variations of the other parameters contribute less than 0.01 dB ICL. Finally, we conduct an experimental evaluation of fusion splicing performance by fabricating four types of NANFs with varying nested tube units, inner tube diameters, and nested tube layers. We characterize the angle alignment sensitivity, high-order mode excitation, and back-reflection performance when various combinations of four types of NANFs are fusion-spliced. Those results of NANF fusion splicing provide valuable insights for the standardization and flexible field deployment.","PeriodicalId":16144,"journal":{"name":"Journal of Lightwave Technology","volume":"44 2","pages":"659-664"},"PeriodicalIF":4.8,"publicationDate":"2025-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The explosive growth of generative AI and cloud computing demands higher-speed transceivers at datacenter interconnects. Conventional wavelength-division-multiplexed (WDM) coherent systems enable large-capacity transmission but suffer from high complexity and cost due to multiple discrete components required at the transceivers. Optical frequency combs (OFCs) potentially offer a promising solution to provide cost-effective multi-wavelength sources, but compact WDM in-phase quadrature (IQ) modulators compatible with OFC sources remain undeveloped. In this paper, we present a silicon photonic WDM IQ modulator using micro-ring modulators (MRMs) for OFC-based coherent systems. Through comprehensive numerical analysis, we reveal that the 4-MRMs/$lambda$ configuration allows nearly chirp-free coherent modulation both in the over- and under-coupled MRM driving conditions. A proof-of-concept experimental demonstration is achieved using a compact silicon photonic chip containing 16 integrated MRMs. Dual-wavelength 28-Gbaud quadrature phase-shift keying signals are generated through precise tuning of resonant wavelengths of all MRMs and phase biases.
{"title":"Silicon Photonic Coherent WDM Transmitter Employing Cascaded Micro-Ring Modulators on a Mach–Zehnder Interferometer","authors":"Shuntaro Maeda;Takahiro Suganuma;Go Soma;Keita Hirashima;Takuya Okimoto;Yoshiaki Nakano;Takuo Tanemura","doi":"10.1109/JLT.2025.3629720","DOIUrl":"https://doi.org/10.1109/JLT.2025.3629720","url":null,"abstract":"The explosive growth of generative AI and cloud computing demands higher-speed transceivers at datacenter interconnects. Conventional wavelength-division-multiplexed (WDM) coherent systems enable large-capacity transmission but suffer from high complexity and cost due to multiple discrete components required at the transceivers. Optical frequency combs (OFCs) potentially offer a promising solution to provide cost-effective multi-wavelength sources, but compact WDM in-phase quadrature (IQ) modulators compatible with OFC sources remain undeveloped. In this paper, we present a silicon photonic WDM IQ modulator using micro-ring modulators (MRMs) for OFC-based coherent systems. Through comprehensive numerical analysis, we reveal that the 4-MRMs/<inline-formula><tex-math>$lambda$</tex-math></inline-formula> configuration allows nearly chirp-free coherent modulation both in the over- and under-coupled MRM driving conditions. A proof-of-concept experimental demonstration is achieved using a compact silicon photonic chip containing 16 integrated MRMs. Dual-wavelength 28-Gbaud quadrature phase-shift keying signals are generated through precise tuning of resonant wavelengths of all MRMs and phase biases.","PeriodicalId":16144,"journal":{"name":"Journal of Lightwave Technology","volume":"44 3","pages":"1061-1067"},"PeriodicalIF":4.8,"publicationDate":"2025-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11231045","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Orbital angular momentum (OAM)-based multiplexing technology provides a novel solution for expanding optical communication capacity and enhancing spectral efficiency by leveraging an additional spatial degree of freedom. In this work, a trench-assisted non-zero dispersion-shifted seven-ring-core fiber is proposed. A single ring core can support up to the OAM4,1 mode, yielding a total of 98 OAM modes compliant with the ITU-T G.655.C standard. Within the C-band, the HE2,1 mode exhibits a minimum dispersion of 1.33 ps/nm/km, while the HE5,1 mode demonstrates a maximum dispersion of 9.08 ps/nm/km. The fiber features a large effective mode area exceeding 336 μm2 and a nonlinear coefficient below 1.97 × 10−3/W/m. In addition to enabling finer dispersion tuning, the trench structure also suppresses crosstalk between adjacent cores. When the transmission distance is 100 km, the fiber achieves below −30 dB inter-core crosstalk.
{"title":"Non-Zero Dispersion-Shifted Fiber With Seven Trench-Assisted Ring Cores for Orbital Angular Momentum Modes","authors":"Yuxiang Huang;Yuanpeng Liu;Yiwen Zhang;Wenqian Zhao;Yuetian Wang;Zhongqi Pan;Lianshan Yan;Yang Yue","doi":"10.1109/JLT.2025.3630071","DOIUrl":"https://doi.org/10.1109/JLT.2025.3630071","url":null,"abstract":"Orbital angular momentum (OAM)-based multiplexing technology provides a novel solution for expanding optical communication capacity and enhancing spectral efficiency by leveraging an additional spatial degree of freedom. In this work, a trench-assisted non-zero dispersion-shifted seven-ring-core fiber is proposed. A single ring core can support up to the OAM<sub>4,1</sub> mode, yielding a total of 98 OAM modes compliant with the ITU-T G.655.C standard. Within the C-band, the HE<sub>2,1</sub> mode exhibits a minimum dispersion of 1.33 ps/nm/km, while the HE<sub>5,1</sub> mode demonstrates a maximum dispersion of 9.08 ps/nm/km. The fiber features a large effective mode area exceeding 336 μm<sup>2</sup> and a nonlinear coefficient below 1.97 × 10<sup>−3</sup>/W/m. In addition to enabling finer dispersion tuning, the trench structure also suppresses crosstalk between adjacent cores. When the transmission distance is 100 km, the fiber achieves below −30 dB inter-core crosstalk.","PeriodicalId":16144,"journal":{"name":"Journal of Lightwave Technology","volume":"44 2","pages":"682-688"},"PeriodicalIF":4.8,"publicationDate":"2025-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-06DOI: 10.1109/JLT.2025.3629543
Wassana Naku;Osamah Alsalman;Chen Zhu
Fiber Bragg gratings (FBGs) have been one of the most widely used optical fiber sensors in both scientific and industrial applications due to their unique advantages of high sensitivity, ease of signal transduction, and capabilities for remote operation and multiplexing. However, the majority of sensing systems based on FBGs can only achieve quasi-distributed sensing along the fiber under test, leaving dark zones in between discrete FBG elements. In this work, we propose and demonstrate a microwave photonics enabled approach for the interrogation of cascaded FBGs to achieve spatially distributed sensing. The core of the system includes an incoherent optical frequency-domain reflectometry module, with the assistance of a dispersive element and a joint time-frequency domain demodulation strategy. By measuring the electrical frequency response of the FBG arrays, followed by the joint time-frequency domain analysis, both the FBG elements and the optical fiber sections connecting the FBGs can be used as sensor devices based on a wavelength-to-delay-mapping technique and interferometry, respectively. Proof-of-concept experiments with a 10-FBG array (10 cm spacing) demonstrated strain sensitivities of –2.37 kHz/µϵ (interferometric channel) and –0.335 ps/µϵ (wavelength-to-delay channel), corresponding to strain resolutions of ∼10 µϵ and ∼0.9 µϵ, respectively. The approach is further shown to support hybrid WDM–TDM interrogation, offering scalability and compatibility with weak FBG arrays.
{"title":"Spatially Distributed Optical Fiber Sensing With Weak Fiber Bragg Grating Arrays Based on Microwave Photonics","authors":"Wassana Naku;Osamah Alsalman;Chen Zhu","doi":"10.1109/JLT.2025.3629543","DOIUrl":"https://doi.org/10.1109/JLT.2025.3629543","url":null,"abstract":"Fiber Bragg gratings (FBGs) have been one of the most widely used optical fiber sensors in both scientific and industrial applications due to their unique advantages of high sensitivity, ease of signal transduction, and capabilities for remote operation and multiplexing. However, the majority of sensing systems based on FBGs can only achieve quasi-distributed sensing along the fiber under test, leaving dark zones in between discrete FBG elements. In this work, we propose and demonstrate a microwave photonics enabled approach for the interrogation of cascaded FBGs to achieve spatially distributed sensing. The core of the system includes an incoherent optical frequency-domain reflectometry module, with the assistance of a dispersive element and a joint time-frequency domain demodulation strategy. By measuring the electrical frequency response of the FBG arrays, followed by the joint time-frequency domain analysis, both the FBG elements and the optical fiber sections connecting the FBGs can be used as sensor devices based on a wavelength-to-delay-mapping technique and interferometry, respectively. Proof-of-concept experiments with a 10-FBG array (10 cm spacing) demonstrated strain sensitivities of –2.37 kHz/µϵ (interferometric channel) and –0.335 ps/µϵ (wavelength-to-delay channel), corresponding to strain resolutions of ∼10 µϵ and ∼0.9 µϵ, respectively. The approach is further shown to support hybrid WDM–TDM interrogation, offering scalability and compatibility with weak FBG arrays.","PeriodicalId":16144,"journal":{"name":"Journal of Lightwave Technology","volume":"44 2","pages":"727-734"},"PeriodicalIF":4.8,"publicationDate":"2025-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Enhancing the intensity of detection light is a key strategy for reducing the Angle Random Walk (ARW) coefficient in optical gyroscopes. Recent studies on broadband light-source-driven resonant fiber-optic gyroscopes (RFOGs) have demonstrated their potential for high sensitivity and simplified design. However, a major limitation of this approach is its low power efficiency. To reduce the ARW, the light source must operate at high power levels, which presents significant challenges for integration and engineering applications. In this study, we propose a novel optical configuration with high reciprocity, utilizing polarization-maintaining fiber and 90° polarization-axis-rotated fusion splicing (90°-PRS) technology to optimize the gyroscope's transmission characteristics. As a result, both light source utilization efficiency and detection resolution are substantially improved. The experimental results demonstrate that, under identical input conditions, the light source efficiency has increased by a factor of 1.86, and the ARW has decreased by 1.3 dB. Our approach provides a crucial solution for realizing low-power, broadband light-source-driven RFOGs, with significant potential for engineering applications.
{"title":"Enhancement of Power Utilization Efficiency and Resolution in Broadband Light-Source-Driven Resonant Fiber-Optic Gyroscopes","authors":"Lingyu Li;Yuqiang Wei;Xiaofu Liu;Guochen Wang;Wei Gao;Boya Zhang","doi":"10.1109/JLT.2025.3629692","DOIUrl":"https://doi.org/10.1109/JLT.2025.3629692","url":null,"abstract":"Enhancing the intensity of detection light is a key strategy for reducing the Angle Random Walk (ARW) coefficient in optical gyroscopes. Recent studies on broadband light-source-driven resonant fiber-optic gyroscopes (RFOGs) have demonstrated their potential for high sensitivity and simplified design. However, a major limitation of this approach is its low power efficiency. To reduce the ARW, the light source must operate at high power levels, which presents significant challenges for integration and engineering applications. In this study, we propose a novel optical configuration with high reciprocity, utilizing polarization-maintaining fiber and 90° polarization-axis-rotated fusion splicing (90°-PRS) technology to optimize the gyroscope's transmission characteristics. As a result, both light source utilization efficiency and detection resolution are substantially improved. The experimental results demonstrate that, under identical input conditions, the light source efficiency has increased by a factor of 1.86, and the ARW has decreased by 1.3 dB. Our approach provides a crucial solution for realizing low-power, broadband light-source-driven RFOGs, with significant potential for engineering applications.","PeriodicalId":16144,"journal":{"name":"Journal of Lightwave Technology","volume":"44 2","pages":"704-709"},"PeriodicalIF":4.8,"publicationDate":"2025-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The previous common understanding of chirped-pulse phase-sensitive optical time-domain reflectometry (CP-ϕOTDR) was that the strain measurement range hinges on precisely matching the detection bandwidth to the chirp bandwidth. Increasing the shot-to-shot measurement range (SSMR) necessarily raises the sampling rate proportionally, posing significant challenges to signal processing and increasing sampling costs. This paper reveals that using only a detection bandwidth equivalent to a portion of the chirp bandwidth can achieve almost the same SSMR, with only a minor difference attributable to the statistical randomness inherent in Rayleigh scattering. Meanwhile, it shows noticeable degradation of sensitivity. The simulations reveal a balance point between detection bandwidth and sensitivity loss. At this balance point, sensitivity loss is threefold while saving one-third of the bandwidth. Beyond this point, further increasing the detection bandwidth yields diminishing sensitivity improvements, whereas reducing the detection bandwidth below this point leads to rapid sensitivity degradation. Experimental validation shifts this balance point to one-fourth, primarily due to measurement deviations. This study provides design guidelines for employing CP-ϕOTDR cost-effectively in large SSMR applications with acceptable sensitivity loss, such as seismic or ocean wave monitoring.
{"title":"On the Detecting Bandwidth of Chirped Pulse ϕ-OTDR","authors":"Zhigeng Ye;Pengbai Xu;Kunhua Wen;Jun Yang;Yuwen Qin","doi":"10.1109/JLT.2025.3628906","DOIUrl":"https://doi.org/10.1109/JLT.2025.3628906","url":null,"abstract":"The previous common understanding of chirped-pulse phase-sensitive optical time-domain reflectometry (CP-ϕOTDR) was that the strain measurement range hinges on precisely matching the detection bandwidth to the chirp bandwidth. Increasing the shot-to-shot measurement range (SSMR) necessarily raises the sampling rate proportionally, posing significant challenges to signal processing and increasing sampling costs. This paper reveals that using only a detection bandwidth equivalent to a portion of the chirp bandwidth can achieve almost the same SSMR, with only a minor difference attributable to the statistical randomness inherent in Rayleigh scattering. Meanwhile, it shows noticeable degradation of sensitivity. The simulations reveal a balance point between detection bandwidth and sensitivity loss. At this balance point, sensitivity loss is threefold while saving one-third of the bandwidth. Beyond this point, further increasing the detection bandwidth yields diminishing sensitivity improvements, whereas reducing the detection bandwidth below this point leads to rapid sensitivity degradation. Experimental validation shifts this balance point to one-fourth, primarily due to measurement deviations. This study provides design guidelines for employing CP-ϕOTDR cost-effectively in large SSMR applications with acceptable sensitivity loss, such as seismic or ocean wave monitoring.","PeriodicalId":16144,"journal":{"name":"Journal of Lightwave Technology","volume":"44 2","pages":"718-726"},"PeriodicalIF":4.8,"publicationDate":"2025-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-05DOI: 10.1109/JLT.2025.3629324
Yang Cheung;Zhenguo Jing;Pengdong Cao;Boda Yu;Yuefeng Qi;Wei Peng
Owing to its diaphragm-free structure, the fiber-optic Fabry-Perot etalon (FPE) sensor exhibits an exceptionally large dynamic range and rapid response characteristics for dynamic pressure sensing. However, its practical application is significantly impeded by its inherently low sensitivity. The optical Vernier effect has been demonstrated as an effective tool for enhancing the sensitivity of fiber-optic interferometric sensors. Previous studies have primarily focused on the design of Vernier-effect-based sensors via various cascaded interferometer configurations for sensitivity enhancement. In practical implementations, an interrogation system comprising a broadband light source and an optical spectrum analyzer (OSA) is typically employed to capture the Vernier spectrum. However, the fixed cavity length of the reference interferometer inherently restricts the flexible adjustment of sensitivity for such sensors. Furthermore, the low sampling rate of conventional OSAs fundamentally limits the dynamic sensing performance of Vernier-effect-based sensors. In this study, we propose a programmable Vernier envelope acquisition (PVEA) technique based on a modulated grating Y-branch (MG-Y) laser for enhancing the sensitivity of FPE sensors. The MG-Y laser performs wavelength scanning over the range of 1527–1567 nm with a sampling interval (SI) of 8 pm, thus enabling the acquisition of the transmission spectrum of the FPE sensor and its corresponding free spectral range (FSR). Benefiting from the flexible wavelength tuning capability of the MG-Y laser, the Vernier envelope was acquired by programmatically adjusting the laser's wavelength sampling interval, ultimately enabling different levels of sensitivity amplification for the FPE sensor without relying on an OSA. The technique was validated using an FPE sensor with a cavity length of 1500 µm, achieving sensitivity enhancement factors of 11.10 and 17.69. Dynamic pressure sensing was successfully demonstrated, exhibiting a measured response time of 320 ms. Furthermore, this technique is adaptable to other types of interferometric sensors.
{"title":"Enhanced Sensitivity for Dynamic Pressure Measurements Using a Fiber-Optic FPE Sensor via Programmable Vernier Envelope Acquisition","authors":"Yang Cheung;Zhenguo Jing;Pengdong Cao;Boda Yu;Yuefeng Qi;Wei Peng","doi":"10.1109/JLT.2025.3629324","DOIUrl":"https://doi.org/10.1109/JLT.2025.3629324","url":null,"abstract":"Owing to its diaphragm-free structure, the fiber-optic Fabry-Perot etalon (FPE) sensor exhibits an exceptionally large dynamic range and rapid response characteristics for dynamic pressure sensing. However, its practical application is significantly impeded by its inherently low sensitivity. The optical Vernier effect has been demonstrated as an effective tool for enhancing the sensitivity of fiber-optic interferometric sensors. Previous studies have primarily focused on the design of Vernier-effect-based sensors via various cascaded interferometer configurations for sensitivity enhancement. In practical implementations, an interrogation system comprising a broadband light source and an optical spectrum analyzer (OSA) is typically employed to capture the Vernier spectrum. However, the fixed cavity length of the reference interferometer inherently restricts the flexible adjustment of sensitivity for such sensors. Furthermore, the low sampling rate of conventional OSAs fundamentally limits the dynamic sensing performance of Vernier-effect-based sensors. In this study, we propose a programmable Vernier envelope acquisition (PVEA) technique based on a modulated grating Y-branch (MG-Y) laser for enhancing the sensitivity of FPE sensors. The MG-Y laser performs wavelength scanning over the range of 1527–1567 nm with a sampling interval (SI) of 8 pm, thus enabling the acquisition of the transmission spectrum of the FPE sensor and its corresponding free spectral range (FSR). Benefiting from the flexible wavelength tuning capability of the MG-Y laser, the Vernier envelope was acquired by programmatically adjusting the laser's wavelength sampling interval, ultimately enabling different levels of sensitivity amplification for the FPE sensor without relying on an OSA. The technique was validated using an FPE sensor with a cavity length of 1500 µm, achieving sensitivity enhancement factors of 11.10 and 17.69. Dynamic pressure sensing was successfully demonstrated, exhibiting a measured response time of 320 ms. Furthermore, this technique is adaptable to other types of interferometric sensors.","PeriodicalId":16144,"journal":{"name":"Journal of Lightwave Technology","volume":"44 2","pages":"787-793"},"PeriodicalIF":4.8,"publicationDate":"2025-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-05DOI: 10.1109/JLT.2025.3629373
Haokun Yang;Gerard Tatel;Liang Chen;Xiaoyi Bao
Viscosity is a key physical parameter that governs fluid motion in a wide spectrum of scientific, biomedical, and industrial applications. This study introduces a compact all-fiber viscometer based on an off-core optical fiber cantilever integrated with a microsphere for viscosity measurement via vibrational damping analysis. The cantilever's free end is immersed in the test liquid and driven by a mechanical actuator, while the viscosity-dependent damping is extracted from the optical response of an interferometric cavity formed between the off-core fiber and the microsphere. The phase delay between the excitation and vibration signals serves as the primary sensing parameter, offering amplitude-insensitive and real-time readout. The all-fiber architecture ensures a miniaturized footprint and requires only a small sample volume (∼50 μL). Experimental validation demonstrates a strong correlation between the measured phase delay and viscosities ranging from 1.144 mPa·s to 8.029 mPa·s. The proposed viscometer offers a robust and practical solution for real-time viscosity monitoring, with potential applications in biomedical diagnostics, industrial process control, and microfluidic systems.
{"title":"Fiber-Optic Viscometer Based on Damping Rate of Off-Core Microsphere Cantilever","authors":"Haokun Yang;Gerard Tatel;Liang Chen;Xiaoyi Bao","doi":"10.1109/JLT.2025.3629373","DOIUrl":"https://doi.org/10.1109/JLT.2025.3629373","url":null,"abstract":"Viscosity is a key physical parameter that governs fluid motion in a wide spectrum of scientific, biomedical, and industrial applications. This study introduces a compact all-fiber viscometer based on an off-core optical fiber cantilever integrated with a microsphere for viscosity measurement via vibrational damping analysis. The cantilever's free end is immersed in the test liquid and driven by a mechanical actuator, while the viscosity-dependent damping is extracted from the optical response of an interferometric cavity formed between the off-core fiber and the microsphere. The phase delay between the excitation and vibration signals serves as the primary sensing parameter, offering amplitude-insensitive and real-time readout. The all-fiber architecture ensures a miniaturized footprint and requires only a small sample volume (∼50 μL). Experimental validation demonstrates a strong correlation between the measured phase delay and viscosities ranging from 1.144 mPa·s to 8.029 mPa·s. The proposed viscometer offers a robust and practical solution for real-time viscosity monitoring, with potential applications in biomedical diagnostics, industrial process control, and microfluidic systems.","PeriodicalId":16144,"journal":{"name":"Journal of Lightwave Technology","volume":"44 2","pages":"760-766"},"PeriodicalIF":4.8,"publicationDate":"2025-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：