{"title":"Precise Distance Measurement by Multi-Wavelength Interferometry Using a Soliton Microcomb","authors":"Jiawen Zhi;Xiaoyang Guo;Jonghan Jin;Hanzhong Wu;Weiqiang Wang;Wenfu Zhang;Chenggang Shao","doi":"10.1109/LPT.2025.3548301","DOIUrl":"https://doi.org/10.1109/LPT.2025.3548301","url":null,"abstract":"In this work, we present a method for precise distance measurement through microcomb-based multi-wavelength interferometry. The high repetition frequency of the microcomb results in a non-ambiguity range confined to the millimeter or centimeter scale. To address this limitation, we leverage the microwave signal inherently carried by the microcomb to significantly extend the non-ambiguity range. Initial coarse distance measurements are obtained via the phases of the microwave signal. These measurements are subsequently refined using multi-wavelength interferometry, with the microcomb serving as the direct signal source. Experimental results indicate that the comparison with the reference distance meter can be within 44 nm. The Allan deviation can reach 43 nm at 4 s, and 8.6 nm at 100 s averaging time. Our system is able to provide a ranging method with nanometric precision and extremely large non-ambiguity range.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"37 7","pages":"377-380"},"PeriodicalIF":2.3,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Temperature Compensation in Fiber Optic Current Sensor Based on Inherent Polarization Quality Factor","authors":"Yueyan Gong;Wenjie Lu;Enjie Gu;Yuejiang Song","doi":"10.1109/LPT.2025.3547757","DOIUrl":"https://doi.org/10.1109/LPT.2025.3547757","url":null,"abstract":"We propose and demonstrate a temperature compensation method based on the inherent polarization quality factor (PQF) of the quarter-waveplate in the fiber optic current sensors. The PQF, dependent on the temperature, can act as a temperature sensor with a resolution of <inline-formula> <tex-math>$2~^{circ }$ </tex-math></inline-formula>C in the experiment. The new compensation coefficient based on PQF is derived from the both relationships of the PQF and the temperature-dependent ratio error. This method can achieve the temperature compensation through internal PQF value instead of direct temperature, and need not require an external temperature sensor to monitor ambient temperature. The new compensation can achieve the accuracy of ratio error 0.2% within the temperature range of <inline-formula> <tex-math>$- 40~^{circ }$ </tex-math></inline-formula>C to <inline-formula> <tex-math>$+ 72~^{circ }$ </tex-math></inline-formula>C, which is satisfied with the 0.2 Class accuracy.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"37 7","pages":"393-396"},"PeriodicalIF":2.3,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143655049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Crosstalk Behaviors in Multicore Fibers Under Deployed Conditions: Role of Structural Fluctuations","authors":"Masanori Koshiba;Kunimasa Saitoh","doi":"10.1109/LPT.2025.3547695","DOIUrl":"https://doi.org/10.1109/LPT.2025.3547695","url":null,"abstract":"Recently, experimental characterizations of deployed multicore fibers (MCFs) with a standard cladding diameter (<inline-formula> <tex-math>$125~mu $ </tex-math></inline-formula>m) have been intensively reported; however, there have been a limited number of theoretical works to elucidate inter-core crosstalk (XT) properties during the cabling and installation processes. In this letter, the effect of a correlation length on the XT behaviors in MCFs under deployed conditions is investigated on the basis of a coupled-power theory. Comparing the calculated results to the measured results, it is confirmed that the XT behaviors in deployed MCFs are mainly dominated by structural fluctuations (random fluctuations of the refractive index distribution or of the fiber geometry along the MCF) and that the correlation length is estimated to be on the order of millimeters.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"37 6","pages":"353-356"},"PeriodicalIF":2.3,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10909485","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143601943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Synchronization of Breathing-Soliton and Dispersive Wave in Mode-Locked Fiber Lasers","authors":"Zhenghu Chang;Tianhao Xian;Chenxiao Hao;Yahan Du;Li Zhan","doi":"10.1109/LPT.2025.3547784","DOIUrl":"https://doi.org/10.1109/LPT.2025.3547784","url":null,"abstract":"Breathing soliton is an attractive non-stationary dynamic in ultrafast fiber lasers, which is one of the hotspots in nonlinear science. Here, using the dispersive Fourier transform technique, we revealed the coexistence of breathing solitons and dispersive waves (DWs) in a mode-locked fiber laser. We found that breathing solitons and DWs interact with each other and synchronous energy coupling is achieved under appropriate gain. This synchronization is a form to stabilize the breathing state due to the balance between the circulating gain of the intracavity pulse and the DW energy dissipation. The stabilized coupling region is disrupted by the gain-competing effect of strongly radiating DW at high pumping. These results help to understand the mechanism of breathing soliton generation and contribute to the optimized design of ultrafast fiber lasers.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"37 7","pages":"381-384"},"PeriodicalIF":2.3,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Optimization of Delta-Sigma Modulator Based on Reinforcement Learning for Mobile Fronthaul","authors":"Zijun Yan;Yixiao Zhu;Guangying Yang;Weisheng Hu","doi":"10.1109/LPT.2025.3546995","DOIUrl":"https://doi.org/10.1109/LPT.2025.3546995","url":null,"abstract":"Delta-sigma modulator (DSM) offers a high-fidelity solution for mobile fronthaul. It achieves a high quantization signal-to-noise ratio through oversampling and noise shaping. However, the DSM is a nonlinear system that lacks of comprehensive design method for the loop filter. The traditional loop filter design methods established on linear filter systems have suboptimal performance. In this work, we propose a reinforcement learning (RL)-based method to optimize the design of the loop filter, which utilizes the historical information. The RL method achieves a 14-dB and a >2.4-dB SNR gain compared to traditional methods and polynomial fitting-based approach, respectively.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"37 7","pages":"397-400"},"PeriodicalIF":2.3,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143655048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. D. Kaimre;Alexander Grabowski;Johan Gustavsson;Anders Larsson
{"title":"25-GBd 850-nm VCSEL for an Extended Temperature Range","authors":"H. D. Kaimre;Alexander Grabowski;Johan Gustavsson;Anders Larsson","doi":"10.1109/LPT.2025.3547156","DOIUrl":"https://doi.org/10.1109/LPT.2025.3547156","url":null,"abstract":"We investigate the performance of a 25 Gbaud 850 nm vertical-cavity surface-emitting laser (VCSEL) with reduced temperature dependence from −40 to 125 °C. The VCSEL design implements chirped quantum wells (QWs) with different compositions to broaden the gain spectrum and achieve sufficient performance over the entire temperature range at constant bias current and modulation voltage. A <inline-formula> <tex-math>$mathrm {6~mu {mathrm {m}} }$ </tex-math></inline-formula> oxide aperture diameter VCSEL supports data transmission at 25 Gb/s NRZ from −40 to 125 °C with 8 mA bias current and 640 mV modulation voltage. The temperature dependencies of basic performance parameters are also compared to those of a conventional VCSEL with identical QWs.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"37 6","pages":"369-372"},"PeriodicalIF":2.3,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Performance Analysis of WSe₂ and MXene Nanocomposite-Based Flexible Photodetector","authors":"Tulika Bajpai;R. K. Nagaria;Sunny;Shweta Tripathi","doi":"10.1109/LPT.2025.3546715","DOIUrl":"https://doi.org/10.1109/LPT.2025.3546715","url":null,"abstract":"This article describes a broadband photodetector based on a PET substrate covered with ITO/ WSe<inline-formula> <tex-math>$_{mathbf {2}}$ </tex-math></inline-formula>: MXene/Al. The dispersion-prepared WSe<inline-formula> <tex-math>$_{mathbf {2}}$ </tex-math></inline-formula>: MXene nanocomposite (NC) serves as the active layer in the device. The nanocomposite film was deposited over ITO-coated PET using the spin coating technique, and the Al contacts were subsequently deposited using thermal evaporation unit. At 300 nm (UV), 750 nm (visible), and 800 nm (IR), the manufactured photodetector exhibits a broadband response with maximum responsivity (A/W) of 77.5 A/W, 1230 A/W, and 1253.17 A/W for 1V bias at a fixed optical power of <inline-formula> <tex-math>$0.118~mu $ </tex-math></inline-formula>W. The WSe<inline-formula> <tex-math>$_{mathbf {2}}$ </tex-math></inline-formula>: MXene nanocomposite shows interesting features for optoelectronic applications.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"37 6","pages":"345-348"},"PeriodicalIF":2.3,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143594416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhiyi Yu;Yang Zhao;Zhiting Li;Shaofu Xu;Weiwen Zou
{"title":"Low-Complexity Photonic Wireless Channel Estimation System Based on Matrix- Condition-Number Theory","authors":"Zhiyi Yu;Yang Zhao;Zhiting Li;Shaofu Xu;Weiwen Zou","doi":"10.1109/LPT.2025.3545867","DOIUrl":"https://doi.org/10.1109/LPT.2025.3545867","url":null,"abstract":"We propose a photonic channel estimation architecture for wireless communication systems with reduced hardware complexity. This work can achieve high-accuracy channel estimation with low cost, solving the problem of existing architecture being too complicated to be practically deployed. Using matrix-condition-number theory, we derived a simplified method to conduct Fourier matrix. Hardware complexity is therefore reduced by tens to hundreds times in OFDM systems. The proof-of-concept experiment was conducted in an OFDM system with 8 channel paths, which contains 128/256/512 subcarriers, respectively. Experimental results show that the mean square errors between the experimental channel state information and practical channel state information lie on the order of 10-4. And the bit error rate is obviously below the forward error correction threshold, satisfying the requirements of OFDM wireless communication.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"37 6","pages":"333-336"},"PeriodicalIF":2.3,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Design of a Silicon-Based Metastructure for Efficient Detection of COVID-19 in Theory","authors":"Chu-Ming Guo;Cheng Yang;Yu-Xin Wei;Xiang Li;Hai-Feng Zhang","doi":"10.1109/LPT.2025.3545070","DOIUrl":"https://doi.org/10.1109/LPT.2025.3545070","url":null,"abstract":"In this letter, an innovative silicon-based metastructure (SBMS) is proposed for second harmonic generation (SHG) to enable the detection of refractive index (RI) and coronavirus disease 2019 (COVID-19) solution concentrations (SC). Utilizing the transfer matrix method (TMM) for analysis and computation, RI sensing is achieved, unveiling the sensitivity of SBMS towards variations in COVID-19 SC. Subsequently, a model correlating COVID-19 SC with the frequency of the second harmonic wave (SHW) transmission peak (TP) is established. Specifically, SBMS demonstrates a RI sensing detection range from 1.1 to 1.4, with a sensitivity of up to 16.946 THz/RIU and an optimal quality factor of <inline-formula> <tex-math>$1.66 times 10 ^{mathbf {5}}$ </tex-math></inline-formula>. Additionally, the relevant values for COVID-19 SC detection are 0 mM to 525 mM (where M is molarity, and 1 M =1 mol/L), 0.71225 THz/M, and <inline-formula> <tex-math>$1.66 times 10 ^{mathbf {5}}$ </tex-math></inline-formula>. The SBMS not only provides an important theoretical foundation for the development of novel virus detection technologies but also expands new possibilities for the application of SBMS in the biomedical field.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"37 6","pages":"325-328"},"PeriodicalIF":2.3,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143521383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sebastiaan Goossens;Yunus Can Gültekin;Olga Vassilieva;Inwoong Kim;Paparao Palacharla;Chigo Okonkwo;Alex Alvarado
{"title":"On Fiber Nonlinearity Mitigation via 4D Geometric Shaping for Next-Generation Single-Span Systems","authors":"Sebastiaan Goossens;Yunus Can Gültekin;Olga Vassilieva;Inwoong Kim;Paparao Palacharla;Chigo Okonkwo;Alex Alvarado","doi":"10.1109/LPT.2025.3544404","DOIUrl":"https://doi.org/10.1109/LPT.2025.3544404","url":null,"abstract":"Four-dimensional (4D) constellations are optimized using geometric shaping (GS) with orthant symmetry (OS) over realistic optical channel models targeting next-generation single-span systems. The optical fiber is modeled via the Manakov equation and is implemented using the split-step Fourier method (SSFM) in a Monte-Carlo based approach. Additional noise sources and losses are added making the link model relevant in practice. Constellations are optimized for different cardinalities, forward error correction code rates, and symbol rates. The SSFM-optimized constellations are reported to offer up to 4% in reach increase with respect to conventional quadrature amplitude modulation (QAM). Comparisons against existing additive white Gaussian noise (AWGN)-optimized constellations show that SSFM-optimized constellations with OS generally negligibly outperform AWGN-optimized counterparts. This somewhat unexpected result leads to the conclusion that AWGN-optimized constellations are a good choice for realistic single-span optical links.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"37 6","pages":"349-352"},"PeriodicalIF":2.3,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143594281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}