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Seed Sources for Spectral Beam Combining via Brillouin De-Interleaving of 1 μm Frequency Combs 基于1 μm频率梳布里渊去交织的波束合成种子源
IF 2.5 3区 工程技术
IEEE Photonics Technology Letters Pub Date : 2025-08-12 DOI: 10.1109/LPT.2025.3598126
Shilpi Arora;Soubhik Pal;C. G. Lakshmi;V. R. Supradeepa
{"title":"Seed Sources for Spectral Beam Combining via Brillouin De-Interleaving of 1 μm Frequency Combs","authors":"Shilpi Arora;Soubhik Pal;C. G. Lakshmi;V. R. Supradeepa","doi":"10.1109/LPT.2025.3598126","DOIUrl":"https://doi.org/10.1109/LPT.2025.3598126","url":null,"abstract":"Spectral Beam Combining (SBC) of multiple fiber laser modules enables high power scaling with applications in material processing and defense. However, it requires multiple laser diodes as seed sources, and each source needs an individual control unit, increasing the system cost and complexity. In contrast, de-multiplexed Optical Frequency Comb (OFC) lines can serve as efficient seed sources for SBC, requiring only a small number of laser diodes to begin with. Owing to the availability of highly efficient gain media such as Yb-doped Fiber Amplifiers (YDFA) for generating high-power laser sources, power scaling using SBC is favorable in the <inline-formula> <tex-math>$1~mu $ </tex-math></inline-formula>m wavelength band. However, due to a dearth of components such as phase modulators and high-resolution de-multiplexers, implementing SBC using frequency combs at this wavelength becomes challenging. In this work, we solve this problem by generating a frequency comb-based seed source with a large channel spacing by de-interleaving a low repetition rate comb using the Vernier effect in Brillouin amplification process. We have obtained a frequency comb with a repetition rate of 34 GHz by selectively amplifying a few lines of an 8.5 GHz repetition rate seed comb using a pump comb with a slightly higher rep-rate (~11.3 GHz). The de-interleaved comb lines are de-multiplexed with a grating-based de-multiplexer, providing ~20 dB of inter-channel suppression and delivering a few mWs of power per channel. This promises to be a compact, easy-to-integrate replacement for multiple seed sources in SBC systems at <inline-formula> <tex-math>$1~mu $ </tex-math></inline-formula>m.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"37 22","pages":"1313-1316"},"PeriodicalIF":2.5,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144891035","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}
引用次数: 0
Displacement Sensing Based on Parasitic Cavity Referencing in Optical Circulators 基于寄生腔参考的光环行器位移传感
IF 2.5 3区 工程技术
IEEE Photonics Technology Letters Pub Date : 2025-08-08 DOI: 10.1109/LPT.2025.3597250
Vinícius Piaia;Paulo Robalinho;António Rodrigues;António Lobo Ribeiro;Susana Silva;Orlando Frazão
{"title":"Displacement Sensing Based on Parasitic Cavity Referencing in Optical Circulators","authors":"Vinícius Piaia;Paulo Robalinho;António Rodrigues;António Lobo Ribeiro;Susana Silva;Orlando Frazão","doi":"10.1109/LPT.2025.3597250","DOIUrl":"https://doi.org/10.1109/LPT.2025.3597250","url":null,"abstract":"In this letter, we propose a method for utilizing the internal cavities of optical circulator devices—commonly referred to as parasitic cavities—as optical reference cavities. The method involves using an optical circulator operating at 1550 nm, illuminated by a light source at 1330 nm, thereby enhancing the amplitude of the interferometric signals generated by the internal optical cavities. The system was characterized by using both an Optical Spectrum Analyzer (OSA) and the Low-Coherence Interferometry (LCI) technique. Experimental results indicate that the Optical Path Difference (OPD) remains constant with varying aperture sizes, thereby confirming the feasibility of employing the optical circulator as a reference sensor. Finally, its performance as a reference sensor is demonstrated through its integration with an external cavity that functions as a displacement sensor.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"37 22","pages":"1293-1296"},"PeriodicalIF":2.5,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144867717","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}
引用次数: 0
High-Speed Long-Range BOTDR by Simplex Coding and Short-Time Fourier Transform Processing 基于单纯形编码和短时傅里叶变换处理的高速远程BOTDR
IF 2.5 3区 工程技术
IEEE Photonics Technology Letters Pub Date : 2025-08-08 DOI: 10.1109/LPT.2025.3596979
Yang Zhang;Jiageng Chen;Hanzhao Li;Xuhui Yu;Zuyuan He
{"title":"High-Speed Long-Range BOTDR by Simplex Coding and Short-Time Fourier Transform Processing","authors":"Yang Zhang;Jiageng Chen;Hanzhao Li;Xuhui Yu;Zuyuan He","doi":"10.1109/LPT.2025.3596979","DOIUrl":"https://doi.org/10.1109/LPT.2025.3596979","url":null,"abstract":"Conventional frequency-scanned Brillouin optical time-domain reflectometry (BOTDR) reconstructs the Brillouin gain spectrum via step-by-step narrowband filtering, which prolongs the measurement duration. In contrast, digital signal processing (DSP)-based BOTDR significantly accelerates the measurement process by employing broad-spectrum frequency analysis. However, to the best of our knowledge, the sensing range of reported DSP-based BOTDR systems remains limited, primarily due to signal-to-noise ratio degradation resulting from noise accumulation inherent to broadband detection. In this work, we propose a coded coherent-detection BOTDR system followed by short-time Fourier transform signal processing, enabling high-speed long-range sensing. In experimental demonstration, an 80.3 km BOTDR with 127-bit simplex-coded sequences is realized, achieving a frequency resolution of 1.34 MHz and a spatial resolution of 4.57 m, within a 60-s total measurement time.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"37 22","pages":"1285-1288"},"PeriodicalIF":2.5,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144867798","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}
引用次数: 0
Frequency-Dependent Variations in DAC ENoB: Predicting Accurate High-Speed Eye-Diagrams DAC ENoB的频率相关变化：预测准确的高速眼图
IF 2.5 3区 工程技术
IEEE Photonics Technology Letters Pub Date : 2025-08-07 DOI: 10.1109/LPT.2025.3596861
Arman Safarnejadian;Wei Shi;Leslie A. Rusch;Ming Zeng
{"title":"Frequency-Dependent Variations in DAC ENoB: Predicting Accurate High-Speed Eye-Diagrams","authors":"Arman Safarnejadian;Wei Shi;Leslie A. Rusch;Ming Zeng","doi":"10.1109/LPT.2025.3596861","DOIUrl":"https://doi.org/10.1109/LPT.2025.3596861","url":null,"abstract":"While previous digital-to-analog converter (DAC) simulation models predict frequency-dependent effective number of bits (ENoB) well, the time domain distortions are exaggerated. We introduce a model preserving ENoB accuracy and it improves the treatment of time-domain behavior. We enhance model accuracy by filtering out spurious frequency content from aliasing and distortion that mask true behavior. We validate frequency-dependent ENoB for three commercial DACs by comparing our model output to known performance. We run a back-to-back electrical experiment to assess the accuracy of the model to predict bit error rate (BER) for baud rates from 70 to 120 Gbaud. We show that, unlike our model, the previous model leads to predictions of eye-opening and BER that are overly pessimistic at higher baud rates. We analyze the influence of oversampling, showcasing the trade-offs between the accuracy of the expected ENoB and the computational complexity. This work provides a comprehensive tool for understanding the constraints imposed by DACs, facilitating the optimization of next-generation optical communication systems.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"37 22","pages":"1297-1300"},"PeriodicalIF":2.5,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144880446","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}
引用次数: 0
Numerical Analysis of Multi-Layer Grating Assisted SPR-Based D-Shaped Optical Fiber 多层光栅辅助spr型d形光纤的数值分析
IF 2.5 3区 工程技术
IEEE Photonics Technology Letters Pub Date : 2025-08-07 DOI: 10.1109/LPT.2025.3596639
Linhang Yang;Haoran Wang;Haoyuan Cai;Longqin Chen;Yushan Chen;Xuchu Deng
{"title":"Numerical Analysis of Multi-Layer Grating Assisted SPR-Based D-Shaped Optical Fiber","authors":"Linhang Yang;Haoran Wang;Haoyuan Cai;Longqin Chen;Yushan Chen;Xuchu Deng","doi":"10.1109/LPT.2025.3596639","DOIUrl":"https://doi.org/10.1109/LPT.2025.3596639","url":null,"abstract":"A novel D-shaped fiber optic surface plasmon resonance (SPR) refractive index (RI) sensor with a bimetallic superimposed double-layer metal oxide grating structure is proposed. Ag/Au layers are coated with ZnO and Ta2O5 to considerably increase the electric field strength on the grating surface. The finite element method is used to calculate and analyze the influence of structural parameters, including grating period and the number of gratings, on the performance of the D-shaped fiber grating sensor. The parameters are optimized to achieve the maximum sensor sensitivity. The analyte RI detection range is 1.34–1.41, with a maximum sensitivity of 15,600 nm/RIU.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"37 22","pages":"1305-1308"},"PeriodicalIF":2.5,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144891034","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}
引用次数: 0
Theoretical Precision Limits of LiDAR in Turbulent Channels 湍流通道激光雷达的理论精度极限
IF 2.5 3区 工程技术
IEEE Photonics Technology Letters Pub Date : 2025-08-07 DOI: 10.1109/LPT.2025.3596633
Tianzhu Zhang;Zhongji Yan;Anning Pang;Anhong Dang
{"title":"Theoretical Precision Limits of LiDAR in Turbulent Channels","authors":"Tianzhu Zhang;Zhongji Yan;Anning Pang;Anhong Dang","doi":"10.1109/LPT.2025.3596633","DOIUrl":"https://doi.org/10.1109/LPT.2025.3596633","url":null,"abstract":"Atmospheric turbulence channels represent a critical factor that must be considered when developing free-space laser applications. While extensive research has been conducted on optical wireless communication (OWC) in turbulent conditions, investigations into light detection and ranging (LiDAR) in turbulent channels remain relatively unexplored. In this letter, theoretical modeling and derivations are developed to characterize the ranging and velocity precision of LiDAR in turbulent channels. The derived Cramér-Rao lower bounds (CRLBs) in Gamma-Gamma channels are verified by Monte Carlo simulation. The CRLBs reveal that, under identical signal-to-noise ratio (SNR) conditions, the precision values at a Rytov variance of 0.3 and 0.6 are 1.56 and 2.37 times those at a Rytov variance of zero for the time-of-flight (ToF) LiDAR, respectively. In the frequency-modulated continuous wave (FMCW) LiDAR system, the corresponding precision value ratios are 1.15 and 1.29. These findings enable rigorous performance evaluation and optimized design of LiDAR systems operating in turbulent environments.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"37 22","pages":"1289-1292"},"PeriodicalIF":2.5,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144868355","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}
引用次数: 0
Dual-Wavelength Q-Switched LED-Pumped Lasers: Hybrid Nd:YLF/Glass Dual-Rod Injection Seeding 双波长调q led泵浦激光器：混合Nd:YLF/玻璃双棒注入播种
IF 2.5 3区 工程技术
IEEE Photonics Technology Letters Pub Date : 2025-08-04 DOI: 10.1109/LPT.2025.3595523
Jianping Shen;Liang Chen;Yang Chen;Fengyang Xing;Fengbo Zhang;Ruize Xia;Huanyu Zuo
{"title":"Dual-Wavelength Q-Switched LED-Pumped Lasers: Hybrid Nd:YLF/Glass Dual-Rod Injection Seeding","authors":"Jianping Shen;Liang Chen;Yang Chen;Fengyang Xing;Fengbo Zhang;Ruize Xia;Huanyu Zuo","doi":"10.1109/LPT.2025.3595523","DOIUrl":"https://doi.org/10.1109/LPT.2025.3595523","url":null,"abstract":"In this letter, we demonstrated a LED-side-pumped hybrid Nd:YLF and Nd:glass laser achieving dual-wavelength operation at 1047 nm and 1053 nm without any optical tuning elements. In the quasi-continuous wave (QCW) regime, the laser achieved a maximum average power of 2.71 W at a 20 Hz repetition. Under active Q-switching, a peak output power of 2.087 kW was obtained with 184 ns pulse duration at 500 Hz repetition rate, while the beam quality factor (M2) measured 9.8. To the best of the authors’ knowledge, this is the first demonstration of a dual-wavelength laser using intracavity seeded light injection technology, providing a novel approach to extend laser emission into adjacent spectral regions and enabling stable terahertz radiation sources.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"37 22","pages":"1281-1284"},"PeriodicalIF":2.5,"publicationDate":"2025-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144867718","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}
引用次数: 0
High-Performance Broadband Photodetectors With V2O5/CuO Heterojunction V2O5/CuO异质结的高性能宽带光电探测器
IF 2.5 3区 工程技术
IEEE Photonics Technology Letters Pub Date : 2025-08-01 DOI: 10.1109/LPT.2025.3594843
T. Srikanth;B. Muni Venkat;Sharmila B;Priyanka Dwivedi
{"title":"High-Performance Broadband Photodetectors With V2O5/CuO Heterojunction","authors":"T. Srikanth;B. Muni Venkat;Sharmila B;Priyanka Dwivedi","doi":"10.1109/LPT.2025.3594843","DOIUrl":"https://doi.org/10.1109/LPT.2025.3594843","url":null,"abstract":"The letter presents the scalable synthesis of CuO, V2O5 and V2O5/CuO nanostructures for broadband photosensing applications. Three different devices using single nanostructured material (CuO, V2O5) and heterostructure (V2O5/CuO) were fabricated and tested for broadband illumination. The heterostructured device demonstrates the responsivity and detectivity of 1.23 A/W and <inline-formula> <tex-math>$0.97times 10 ^{11}$ </tex-math></inline-formula> Jones at 360 nm respectively. The responsivity of the heterostructured device is 67.3 times and 13.8 times higher than CuO and V2O5 respectively. The demonstrated results indicate that the V2O5/CuO heterostructure could be useful for real time optical sensing applications.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"37 22","pages":"1309-1312"},"PeriodicalIF":2.5,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144891339","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}
引用次数: 0
Carrier-Assisted Differential Detection for Indoor Optical Wireless Communications 室内无线光通信载波辅助差分检测
IF 2.5 3区 工程技术
IEEE Photonics Technology Letters Pub Date : 2025-07-30 DOI: 10.1109/LPT.2025.3593958
Junyu Wu;Jianghao Li;Honglin Ji;William Shieh
{"title":"Carrier-Assisted Differential Detection for Indoor Optical Wireless Communications","authors":"Junyu Wu;Jianghao Li;Honglin Ji;William Shieh","doi":"10.1109/LPT.2025.3593958","DOIUrl":"https://doi.org/10.1109/LPT.2025.3593958","url":null,"abstract":"Self-coherent detection possesses superiority over intensity modulation direct detection and coherent detection due to its balance on spectrum efficiency and structure complexity. Consequently, self-coherent detection may also be feasible for indoor optical wireless communications (OWCs) due to its ability to recover complex-valued signal without a local oscillator laser. In this letter, for the first time, an indoor OWCs system employing carrier-assisted differential detection (CADD) receiver with a data rate of 50 Gb/s is proposed and experimentally verified. To comply with the eye and skin safety regulation, a free-space optical launch power of 6.5 dBm is set for free-space transmission. As a proof-of-concept, an indoor OWCs system experiment of 25 GBaud QPSK OFDM is demonstrated, achieving a data rate of 50Gb/s over 7.5 m free-space link with a sensitivity of −24 dBm. The result indicates the feasibility of CADD receiver for high-speed indoor OWCs systems.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"37 23","pages":"1333-1336"},"PeriodicalIF":2.5,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144904697","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}
引用次数: 0
Photonic Generation of Crossed-Dual-Chirp THz LFM Signal by Single Tunable Laser 单可调谐激光产生交叉双啁啾太赫兹LFM信号
IF 2.5 3区 工程技术
IEEE Photonics Technology Letters Pub Date : 2025-07-30 DOI: 10.1109/LPT.2025.3594261
Shenghong Ye;Yiqing Wang;Bo Li;Ryota Kaide;Ming Che;Yuya Mikami;Yuta Ueda;Kazutoshi Kato
{"title":"Photonic Generation of Crossed-Dual-Chirp THz LFM Signal by Single Tunable Laser","authors":"Shenghong Ye;Yiqing Wang;Bo Li;Ryota Kaide;Ming Che;Yuya Mikami;Yuta Ueda;Kazutoshi Kato","doi":"10.1109/LPT.2025.3594261","DOIUrl":"https://doi.org/10.1109/LPT.2025.3594261","url":null,"abstract":"We propose a cost-effective and hardware simplified photonics-based terahertz (THz) linear frequency modulated (LFM) signal generation system. The system utilizes only a single ultra-fast wavelength tunable laser leveraging electro-optic effect combined with commercial fiber self-delay. A crossed-dual-chirp, which consists of simultaneous up-chirp and down-chirp THz LFM signals within the same 400 ns period was generated with a bandwidth of 14.6 GHz and center frequency of 284 GHz. A high chirp rate of 0.0365 GHz/ns was achieved using only a low-cost voltage controller operating at MHz frequency. This cost-effective yet high-performance solution generates crossed-dual-chirp waveforms that are expected to mitigate the Doppler error, making it suitable for high-speed target detection. The proposed system demonstrates significant advantages in practical applications, as it successfully balances performance requirements with implementation complexity.","PeriodicalId":13065,"journal":{"name":"IEEE Photonics Technology Letters","volume":"37 22","pages":"1269-1272"},"PeriodicalIF":2.5,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144868353","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}
引用次数: 0
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