Gu Zhenyu, Ning Tigang, Pei Li, Zheng Jingjing, Li Jing, Hu Zhouyi, Guo Hao
{"title":"Resonance mechanism in composite material hollow core fiber","authors":"Gu Zhenyu, Ning Tigang, Pei Li, Zheng Jingjing, Li Jing, Hu Zhouyi, Guo Hao","doi":"10.1016/j.optlastec.2025.113585","DOIUrl":"10.1016/j.optlastec.2025.113585","url":null,"abstract":"<div><div>In this study, we derived the characteristic equation for dielectric modes in composite material dielectric tubes and analyzed the resonance mechanism of composite material antiresonant fibers based on the inhibited coupling theory. A simplified cutoff equation was also proposed, successfully predicting the separation of loss peaks for electric-dominant modes (TM and EH) and magnetic-dominant modes (TE and HE) in composite material antiresonant fibers. The results from both the characteristic and cutoff equations demonstrated great agreement with finite element method simulations. The proposed model simplifies the design process by reducing the computational complexity compared to traditional methods. Additionally, it provides valuable insights into the waveguide behavior and loss mechanisms of composite material antiresonant fibers, aiding in the optimization of these fibers for practical applications in areas such as high-speed communication and sensitive sensing. This work offers a more efficient approach to understanding and designing composite material antiresonant fibers, contributing to the advancement of fiber-optic technology.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113585"},"PeriodicalIF":4.6,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144694507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wei Zhou , Lixiong Wang , Hui Zhao , Zhen Pan , Xianghan Meng , Jianjun Pan
{"title":"Demodulation method for vibration sensors of ultra-weak fiber Bragg grating using a Self-Referencing signal based on DBNs with ensemble learning","authors":"Wei Zhou , Lixiong Wang , Hui Zhao , Zhen Pan , Xianghan Meng , Jianjun Pan","doi":"10.1016/j.optlastec.2025.113593","DOIUrl":"10.1016/j.optlastec.2025.113593","url":null,"abstract":"<div><div>The vibration signal with high signal-to-noise ratio (SNR) is difficult to be obtained in the conventional methods owing to the influence of environment and equipment in ultra-weak fiber Bragg grating (UWFBG) distributed vibration sensor. In this paper, a novel demodulation method using a self-referencing signal based on deep belief networks (DBNs) with ensemble learning is proposed, to enhance the SNR of demodulated signal. The reference interferometer can obtain the information of environmental noise and system noise. The DBN is employed to construct a dynamic correlation model between the interference signal and vibration signals. By extracting multidimensional features, the model learns how six output interference signals are changed with vibration in measured environment. To further promote the performance of single DBN model, an ensemble learning method is used to learn the knowledge of five different DBN models. Experimental results demonstrate that in the range of 10 Hz to 1000 Hz, the ensemble DBN model can achieve vibration measurement with higher SNR. The proposed method can reduce background noise by 22.8 dB in 1 kHz vibration environment, and the SNR is 79.9 dB. It can be drawn conclusion that the proposed method can weaken the influence of environmental noise and inconsistent splitting ratio of 1 × 3 coupler, to make demodulation result with higher SNR in vibration sensor demodulation.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113593"},"PeriodicalIF":4.6,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144686660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yangdi Su , Bowen Hong , Sensen Liu , Yinghong Guo , Kai Ni , Ben Xu
{"title":"Near-infrared image-based vascular network extraction using enhanced matched filtering","authors":"Yangdi Su , Bowen Hong , Sensen Liu , Yinghong Guo , Kai Ni , Ben Xu","doi":"10.1016/j.optlastec.2025.113596","DOIUrl":"10.1016/j.optlastec.2025.113596","url":null,"abstract":"<div><div>Intravenous injection and venipuncture are vital in modern medicine, making the positioning of surface veins crucial. Utilizing the absorption characteristics of deoxyhemoglobin in the near-infrared spectrum, a vascular network recognition algorithm using near-infrared images and matched filtering is proposed. An 850 nm LED serves as the auxiliary lighting source, and the Contrast Limited Adaptive Histogram Equalization (CLAHE) method improves infrared image contrast. Based on the morphological characteristics of the infrared vein images, enhanced matched filtering successfully extracts vessels, increasing the signal-to-noise ratio and enabling accurate extraction of even small vessels. The algorithm’s reliability is validated with the Digital Retinal Images for Vessel Extraction (DRIVE) dataset, achieving a Dice coefficient of 73.92. Due to its low computational complexity, fast speed, and excellent performance, a handheld portable vein projector has been developed, featuring real-time infrared image acquisition, processing, and in-situ vein distribution projection, and successfully applied in medical practice.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113596"},"PeriodicalIF":4.6,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144686661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Haohan Guo , Peidong Hua , Kun Liu , Ji Liu , Jinqi Deng , Huafang Wang , Junfeng Jiang , Tiegen Liu , Zhenyang Ding
{"title":"Micrometer level distributed cancer biomarker biosensing based on optical frequency domain reflectometry","authors":"Haohan Guo , Peidong Hua , Kun Liu , Ji Liu , Jinqi Deng , Huafang Wang , Junfeng Jiang , Tiegen Liu , Zhenyang Ding","doi":"10.1016/j.optlastec.2025.113630","DOIUrl":"10.1016/j.optlastec.2025.113630","url":null,"abstract":"<div><div>We present a distributed cancer biomarker biosensing with a micrometer level spatial resolution by functionalized tapered fiber based on optical frequency domain reflectometry (OFDR). A Graphene oxide (GO) film is fixed on the surface of the tapered fiber. Carcinoembryonic antigen-related cell adhesion molecules 5 monoclonal antibody (CEACAM5 mAb) layer is coated on the entire GO fixed tapered region by polydopamine (PDA) assisted immobilization as the functionalized sensing element to achieve the sensing of carcinoembryonic antigen (CEA). To enhance the ability of localization for biochemical substances, we apply a differential relative phase method with a radius denoising method in OFDR to demodulate phase variations of Rayleigh backscattering caused by the biomolecular binding reaction. The measurable concentrations of CEA and phase variations have a good linearity in a range from 1 ng/ml to 8 ng/ml. The proposed distributed biosensor has a limit of detection (LOD) of is 1 ng/ml and a sensitivity of 0.0864 rad/(ng/mL). We also verify that the proposed distributed biosensor can locate the concentration changes of CEA with a sensing spatial resolution of 80 μm. The proposed distributed biosensor provides a potential tool to <em>in situ</em> detect and locate tumor cells at a spatial resolution of micrometer level.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113630"},"PeriodicalIF":4.6,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144687299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Multi-parameter tactile sensing and recognition for robotic finger based on Bi-FBG","authors":"Dong Xiaotian, Yu Youlong, Yu Qianchun, Miao Kexin, Zhou Qinzhi","doi":"10.1016/j.optlastec.2025.113634","DOIUrl":"10.1016/j.optlastec.2025.113634","url":null,"abstract":"<div><div>In order to identify the temperature, surface roughness and two-dimensional (2D) shape simultaneously, a multi-parameter tactile sensing system based on birefringent fiber Bragg grating (Bi-FBG) is proposed. The system is embedded in a robotic finger and follows the motion of finger to enhance tactile sensing capabilities. In the sensing system, the dual-peak sensing characteristics of Bi-FBG are employed to effectively decouple temperature and strain information. The Bi-FBG sensor was calibrated with K<sub>Tx</sub> = 0.0192 nm/°C, K<sub>Ty</sub> = 0.0180 nm/°C, and K<sub>εx</sub> = K<sub>εy</sub> = 0.00121 nm/με. Meanwhile, wavelet transform and least rectangles method are used to analyze strain signals from multi-directional dynamic sliding. This enables reconstruction of the object boundaries and extraction of the surface roughness information. The experimental results show that the sensing system can distinguish roughness levels, reconstruct 2D shapes with a relative error of 0.02, and achieve high-precision temperature measurement. This study demonstrates the system’s capability for high-precision, multi-parameter tactile perception and broadens the application prospects of robotic sensing technology.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113634"},"PeriodicalIF":4.6,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144696827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wei Liu , Siying He , Jingxuan Xu , Yongzhen Chen , Wanqing Li , Hong Shu , Puhong Duan , Fang Zhu
{"title":"Underwater image enhancement based on adaptive information transfer and weighted stationary wavelet perception fusion","authors":"Wei Liu , Siying He , Jingxuan Xu , Yongzhen Chen , Wanqing Li , Hong Shu , Puhong Duan , Fang Zhu","doi":"10.1016/j.optlastec.2025.113625","DOIUrl":"10.1016/j.optlastec.2025.113625","url":null,"abstract":"<div><div>Underwater images commonly suffer from issues like color distortion, low contrast, and blurred details. To tackle these degradation problems, we propose an underwater image enhancement (UIE) method named ATWF, which is based on adaptive information transfer and weighted stationary wavelet perception fusion. This method firstly introduces an adaptive information transfer strategy, grounded in histogram similarity cue, to effectively compensate for the attenuation channels. Subsequently, it integrates linear stretching to increase the dynamic range of color compensated image. Secondly, an adaptive gamma correction algorithm is used to enhance the overall contrast of the color-corrected image, and a multi-scale side window box filter (SWBF) technique is employed to improve its local details simultaneously. Finally, the stationary wavelet transform is used to decompose the enhanced images into low-frequency (LF) and high-frequency (HF) components. Perception fusion rules tailored to the different characteristics of each component are devised to improve the visual quality of the resultant image. Experiments on multiple public datasets show that: (1) ATWF can effectively correct color distortion; (2) it significantly improves image contrast, suppresses noise, and highlights details; (3) in terms of qualitative and quantitative evaluation, corner detection, image matching, and image segmentation, it outperforms or is comparable to other mainstream UIE methods. Additionally, ATWF demonstrates strong generalization ability in various complex degradation scenarios.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113625"},"PeriodicalIF":4.6,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Robust interferogram processing using deep learning and signal subspace method for phase derivative estimation","authors":"Viren S Ram , Rajshekhar Gannavarpu","doi":"10.1016/j.optlastec.2025.113616","DOIUrl":"10.1016/j.optlastec.2025.113616","url":null,"abstract":"<div><div>For non-destructive deformation metrology using optical interferometry, the derivative of phase map encoded in the interferogram signal contains crucial information about physical quantities such as displacement derivatives and strain. Hence, reliable retrieval of phase derivative is of great practical significance in precision metrology. However, this information is often difficult to retrieve in the presence of severe noise and imaging artifacts such as non-uniform intensity variations. In this paper, we propose a deep learning assisted signal subspace approach for extracting phase derivatives. The main advantages of the proposed method include robustness against severe noise and tolerance against interferogram abnormalities. The performance of the proposed method is validated using rigorous numerical simulations. The practical utility of the method is shown via experimental results obtained in digital holographic interferometry.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113616"},"PeriodicalIF":4.6,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Research on real-time gear fault detection and classification technology based on EFPI vibration sensor","authors":"Zexin Li , Shengpeng Wan , Junsong Yu","doi":"10.1016/j.optlastec.2025.113627","DOIUrl":"10.1016/j.optlastec.2025.113627","url":null,"abstract":"<div><div>In order to detect the health status of gears working for long periods of time in harsh environments such as high speed and high load, this paper studies the real-time detection and classification technology of gear faults based on fiber-optic extrinsic Fabry-Perot interferometer (EFPI) vibration sensors. A deep learning model of 1D-LSAM-CNN-BiLSTM is proposed to improve the accuracy and speed of gear fault classification. Firstly, three different types of gears are prepared, each including a health gear, a wear gear, and a tooth breakage gear. Then, a feedback based single wavelength intensity demodulation EFPI system is used to collect vibration signals for 27 gear fault categories. The collected vibration signals are transmitted to the computer through the ACM8211 gigabit ethernet module and stored. The 1D-LSAM-CNN-BiLSTM deep learning model automatically reads stored data, preprocesses and trains it. The trained model can perform real-time fault classification on the collected vibration signals. The experimental results show that the real-time gear fault detection and classification system proposed in this paper has high recognition accuracy.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113627"},"PeriodicalIF":4.6,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Vasil’ev , M. Zhezhu , H. Parsamyan , G. Baghdasaryan , M. Sargsyan , D.A. Ghazaryan , H. Gharagulyan
{"title":"Revisiting THz absorption in GO and rGO liquid crystalline films","authors":"A. Vasil’ev , M. Zhezhu , H. Parsamyan , G. Baghdasaryan , M. Sargsyan , D.A. Ghazaryan , H. Gharagulyan","doi":"10.1016/j.optlastec.2025.113628","DOIUrl":"10.1016/j.optlastec.2025.113628","url":null,"abstract":"<div><div>With a swift progress in modern high-throughput communication systems, security, sensing and medicine utilizing THz range technologies, the demand for easy-to-fabricate, lightweight and high-performance absorbing materials has increased drastically. Notably, traditional approaches of eliminating unwanted radiation based on metasurfaces often face fabrication challenges limiting their practicality. In this study, we propose a straightforward approach for fabricating graphene oxide (GO) and reduced graphene oxide (rGO) liquid crystalline (LC) films <em>via</em> the vacuum filtration method and investigate their THz absorption characteristics. Here, the presence of LC phase in our electrochemically exfoliated GO and rGO LC films was confirmed by ellipsometric characterization. THz time-domain spectroscopy (TDS) measurements reveal that these films possess a low reflectance and transmittance confirming their strong absorptive properties within 0.4–1.6 THz frequency range for ∼ 2 μm thick GO and rGO LC films. Particularly, the GOLC film shows ∼ 37 % average absorption at a thickness of 2.12 µm, which is 221 times smaller than the central wavelength. Similarly, the rGOLC film reaches ∼ 50 % absorption with a 1.68 µm thickness, 279 times smaller than the central wavelength. These findings provide valuable insights for development of GO- and rGO-based LC THz absorbers with highly tunable properties due to the ordering of GO flakes. Specifically, the LC phase of GO contributes to the formation of more uniform films with enhanced absorption due to the compact stacking and denser packing, compared to conventional GO films with randomly oriented GO flakes..</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113628"},"PeriodicalIF":4.6,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Haiyang Xie , Pengrun Ying , Binxin Wang , Ruixin Tang , Ziyu Luo , Yijun He , Hui Liu
{"title":"Bidirectional ytterbium-doped fiber laser with independent nonlinear-polarization-rotation mode-locking and gain medium","authors":"Haiyang Xie , Pengrun Ying , Binxin Wang , Ruixin Tang , Ziyu Luo , Yijun He , Hui Liu","doi":"10.1016/j.optlastec.2025.113574","DOIUrl":"10.1016/j.optlastec.2025.113574","url":null,"abstract":"<div><div>This paper presents a bidirectional mode-locked ytterbium-doped fiber laser with independent nonlinear polarization rotation (NPR) mode-locking and gain medium. This laser achieves robust bidirectional NPR mode-locking operation without the need for condition of saturation critical power and enables a direct and wide range control over the repetition frequency difference (0–38 kHz). The pulse energy reaches up to 2.8 nJ. The long-term fluctuation of the repetition rates is well-consistent, resulting in a stable repetition rate difference with standard deviation of 0.8 Hz while the repetition rate varies as large as 180 Hz. The intensity noise correlation and phase noise consistency are measured, revealing the complex noise behaviors in detail and the room for enhancing the mutual coherence. The interferograms are observed and Fourier transformed, resulting in a spectrum that is consistent with the optical spectra. This work offers an alternative solution for the bidirectional fiber mode-locked laser with pulse energy in the nanojoule range that benefits both linear and nonlinear dual-comb applications.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113574"},"PeriodicalIF":4.6,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}