Infrared Physics & Technology最新文献

{"title":"Infrared small target detection based on isolated hyperedge","authors":"Xiao-ling Ge,&nbsp;Wei-xian Qian","doi":"10.1016/j.infrared.2025.105752","DOIUrl":"10.1016/j.infrared.2025.105752","url":null,"abstract":"<div><div>Detecting infrared small targets robustly in complex backgrounds is crucial for Infrared Search and Track (IRST) applications. However, high-intensity structures in the background, such as sharp edges, pose a challenging task, especially when the target has a low signal-to-noise ratio. We propose an Intuitionistic Fuzzy Hypergraph-based Target Detection method (IFHTD) to address this issue. IFHTD models the uncertainty of small target detection by intuitively fuzzifying the entire image at the pixel level. We define weighted intuitionistic fuzzy entropy as a membership function for target attributes in image blocks, thereby obtaining intuitionistic fuzzy sets for each image block vertex. Subsequently, the detection of infrared small targets is transformed into detecting regionally isolated hyperedges. Using intuitionistic fuzzy divergence distance metrics, we construct an intuitionistic fuzzy hypergraph for an image window. Isolated hyperedges are extracted from the centers of the image window using a predefined threshold. These isolated hyperedges are assigned weights to create a weighted graph, doubling as the infrared target’s saliency map. Experimental results demonstrate our algorithm’s robustness and effectiveness in practical infrared small target detection scenarios.</div></div>","PeriodicalId":13549,"journal":{"name":"Infrared Physics & Technology","volume":"146 ","pages":"Article 105752"},"PeriodicalIF":3.1,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143436803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"High laser damage threshold GaN-based liquid crystal devices for 2 μm band applications","authors":"YanTao Song ,&nbsp;Wei Fan ,&nbsp;JunJie Sun ,&nbsp;DaJie Huang ,&nbsp;He Cheng ,&nbsp;HaoYuan Pan ,&nbsp;FuYe Wang","doi":"10.1016/j.infrared.2025.105768","DOIUrl":"10.1016/j.infrared.2025.105768","url":null,"abstract":"<div><div>With advancements in laser technology toward higher energy levels, greater average power, and multi-wavelength applications, optical field modulation devices are required to cover broader wavelength ranges, endure higher repetition rates, and exhibit improved laser damage thresholds. Laser sources in the 2 μm band offer significant potential for both scientific and industrial applications. Nevertheless, the development of optical field modulation devices with high laser damage thresholds in this wavelength range presents significant technical challenges. Our research group has investigated the feasibility of employing GaN-based liquid crystal devices—characterized as third-generation semiconductors—for applications in the 2 μm band. These devices demonstrate spectral transmittance spanning the range of 500 nm to 3 μm, achieving the maximum on–off ratio of 256:1, withstanding laser irradiation up to 15 W at 2 μm (spot size: 1.208 mm, on–off ratio of 20:1), and supporting a peak power density tolerance of 2534 W/cm² and a maximum repetition rate of 28 Hz.</div></div>","PeriodicalId":13549,"journal":{"name":"Infrared Physics & Technology","volume":"146 ","pages":"Article 105768"},"PeriodicalIF":3.1,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143436964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Design and hot embossing of glass micro gratings for polarization-insensitive beam splitter","authors":"Feng Gong ,&nbsp;Rongxi Qin ,&nbsp;Kang Yang ,&nbsp;Qingrui Ren ,&nbsp;Gao Yang","doi":"10.1016/j.infrared.2025.105763","DOIUrl":"10.1016/j.infrared.2025.105763","url":null,"abstract":"<div><div>Polarization-insensitive beam splitters play significant roles in the manipulation of optical beams and signal processing. However, existing fabrication methods for glass beam splitters suffer from cumbersome steps, long cycle time, and insufficient accuracy on the micrometer scale. Therefore, it is non-trivial to seek for an alternative method for fabrication of the beam splitters with high efficiency and high precision. This study aims to design a high-performance polarization-insensitive glass beam splitting grating and to demonstrate the efficiency and accuracy of hot embossing technology in its fabrication for the first time. Firstly, the Fourier modal method is adopted to simulate the diffraction efficiency of the beam-splitting gratings with different geometric parameters at the operating wavelength of 808 nm. The effects of different geometric parameters on the diffraction efficiency are evaluated. After that, the optimal geometric parameters of the grating are calculated, with a ridge width of about 6 μm. According to the optimized optical design, the monocrystalline silicon grating is produced by the standard photolithography-etching steps. In the next step, a protective coating is deposited on the silicon mold by the physical vapor deposition. Subsequently, the micro grating features are replicated from the coated silicon mold to the glass substrate by hot embossing. The surface topography of the coated silicon mold and the embossed glass grating are measured by the white light interferometer, showing a decent filling rate of 96.79 %. Moreover, the diffraction efficiency of the glass grating is detected by a home-made optical testing platform, and the detected data are consistent with the simulated ones. Therefore, hot embossing is a promising method for mass production of glass beam splitting gratings.</div></div>","PeriodicalId":13549,"journal":{"name":"Infrared Physics & Technology","volume":"146 ","pages":"Article 105763"},"PeriodicalIF":3.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143436802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Narrow-linewidth single-longitudinal-mode erbium-doped fiber laser with high OSNR, high output power and low wavelength drift","authors":"Pengfei Wang ,&nbsp;Haoyu Tan ,&nbsp;Fengping Yan ,&nbsp;Ting Li ,&nbsp;Qi Qin ,&nbsp;Ting Feng ,&nbsp;Hao Guo ,&nbsp;Yongpeng Xie ,&nbsp;Siyu Peng ,&nbsp;Qiuyu Huang ,&nbsp;Jiawen Liu ,&nbsp;Peng Liu ,&nbsp;Dandan Yang ,&nbsp;Shiying Zan","doi":"10.1016/j.infrared.2025.105762","DOIUrl":"10.1016/j.infrared.2025.105762","url":null,"abstract":"<div><div>A high optical signal-to-noise ratio (OSNR), high output power, low wavelength drift, and narrow-linewidth single-longitudinal-mode (SLM) erbium-doped fiber laser (EDFL), the subject of this research, consists of three parts: main cavity, self-injection locked feedback mechanism and erbium-doped fiber amplifier (EDFA). During an observation time of 60 min, the proposed EDFL can generate SLM lasing with an OSNR &gt; 75.04 dB. The maximum wavelength drift in that time remained at a low level of 0.0085 nm. Moreover, the maximum SLM output optical power could reach 157.20 mW. Measures of the output laser performance, such as dependence of output power variations on pump power, power spectral density of frequency fluctuation, and frequency shift of the relaxation oscillation peak, were investigated and analyzed in this research.</div></div>","PeriodicalId":13549,"journal":{"name":"Infrared Physics & Technology","volume":"146 ","pages":"Article 105762"},"PeriodicalIF":3.1,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"24 mJ sub-nanosecond kilohertz 515 nm laser achieved by the KTP crystal","authors":"Zhang Xin ,&nbsp;Yu Jinghua ,&nbsp;Sun Junjie ,&nbsp;Chen Yi ,&nbsp;Zhang Yiwen ,&nbsp;Fan Jiaoyu ,&nbsp;Han Renjie ,&nbsp;Chen Fei","doi":"10.1016/j.infrared.2025.105764","DOIUrl":"10.1016/j.infrared.2025.105764","url":null,"abstract":"<div><div>In response to the demand for high-energy, high-repetition-rate sub-nanosecond green lasers in industrial and other fields, as well as the currently problems with relatively single implementation solutions and high crystal costs, it has been proposed that the KTP crystal was used as frequency doubling crystal and the 1030 nm disk regenerative amplifier as the fundamental frequency laser for the high-energy 515 nm sub-nanosecond laser. The maximum output energy is 24.17 mJ with a repetition rate of 1 kHz. The pulse width measured by the oscilloscope is less then 719 ps. The variation trend of the frequency doubling power, efficiency and the crystal temperature with the injection power for the crystal lengths of 2.5 mm and 5 mm has been done in experiment. According to the results of frequency doubling efficiency and temperature changes with different lengths crystals, the increased temperature in crystal leading to the phase mismatch is the main reason for frequency doubling efficiency decreased. The longer the crystal, the faster the temperature rises, and the more sever impacts on the frequency doubling efficiency. Therefore, in order to further improve the frequency doubling efficiency of high-energy sub-nanosecond kilohertz green laser based on KTP crystals, it is necessary to consider the influence of temperature on phase matching in advance and optimize the crystal cutting angle based on actual temperature.</div></div>","PeriodicalId":13549,"journal":{"name":"Infrared Physics & Technology","volume":"146 ","pages":"Article 105764"},"PeriodicalIF":3.1,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143436800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 flexible ultrasonic infrared detection of crack defects in irregular metal components","authors":"Feng Yang ,&nbsp;Fei Wang ,&nbsp;Rongcheng Li ,&nbsp;Stefano Sfarra ,&nbsp;Lixia Xu ,&nbsp;Yaodong Yang ,&nbsp;Lixia Liu ,&nbsp;Honghao Yue ,&nbsp;Junyan Liu","doi":"10.1016/j.infrared.2025.105755","DOIUrl":"10.1016/j.infrared.2025.105755","url":null,"abstract":"<div><div>A novel flexible ultrasonic infrared nondestructive testing approach employing a spherical excitation head was proposed to better meet the detection requirements of metal surfaces with complex geometries. Initially, by integrating Hertzian contact theory and fractal theory, the contact mechanism of the spherical excitation head in ultrasonic dry coupling was systematically analyzed, with a particular focus on the key factors governing interface contact stiffness. Subsequently, simulation studies unveiled the stress field distribution induced by the spherical excitation head, along with the associated thermal effects at crack defects. It was demonstrated that the spherical excitation head could generate a more uniform and stable stress field while amplifying thermal responses in defective regions. Ultimately, based on these insights, a flexible ultrasonic infrared nondestructive testing system equipped with two orthogonal digital lock-in algorithms was developed, and experimental validation was conducted on connecting rod specimens with crack defects. The results substantiate that this method can accurately detect cracks measuring 10.52 mm and 21.24 mm in length.</div></div>","PeriodicalId":13549,"journal":{"name":"Infrared Physics & Technology","volume":"146 ","pages":"Article 105755"},"PeriodicalIF":3.1,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Evaluating effects of glare on the monitoring of building facade health condition by analyzing the infrared thermal images collected under different weather conditions","authors":"Yishuo Huang,&nbsp;Chia-Chien Hung,&nbsp;Chih-Hung Chiang","doi":"10.1016/j.infrared.2025.105754","DOIUrl":"10.1016/j.infrared.2025.105754","url":null,"abstract":"<div><div>Infrared thermal images are widely adopted to monitor the health condition of building facades. Image segmentation can usually segment IRT images by grouping those pixels with similar surface temperatures so that the segmented regions, which correspond to different surface temperatures, can be used for defect detection. Recently, researchers have proposed that intensity inhomogeneity can be approximated, implying that extra information (like glares, shadows, etc.) is included in the pixels of IRT images. The approximated intensity inhomogeneity can be used to enhance or smooth the given IRT images so that the images can be easily interpreted. We propose an innovative image model incorporating intensity inhomogeneity. Assuming that intensity inhomogeneity can be linearly interpreted, it can be presented using Taylor’s expansion. For simplicity, only the first and second terms are included in the image model. The optical-radiative properties of façade materials are usually unknown, while the IRT image containing different façade materials is processed. The entropy of the IRT image reflects these properties. The entropy of a given image can be high if the areas with high-intensity inhomogeneity need more pixels to be included in the image model. By contrast, the areas with low-intensity inhomogeneity need fewer pixels to be included in the image model. Hence, the entropy of the IRT image is used to determine the window sizes. The proposed image model involving Taylor’s expansion and multiple window sizes can be used to determine intensity inhomogeneity and segmented regions through the introduction of level-set functions and an iterative scheme. The processed results demonstrate that while the glare effects dominate the intensity inhomogeneity, the segmented results are affected, and the corresponding image regions cannot be used for defect detection. IRT images are collected on sunny days. In this study, the proposed approach is used to evaluate three sets of IRT images collected on rainy days, and the processed results indicate that intensity inhomogeneity exists in those collected images, but the thermal patterns of defects are not fully developed. The proposed image model incorporates image segmentation. The given images can be segmented, and their intensity inhomogeneity can be computed by introducing level-set functions and an iterative scheme. When the approximated intensity inhomogeneity is less than 1.0 in an IRT image, the areas are enhanced. Conversely, if the approximated intensity inhomogeneity is larger than 1.0, the areas are smoothed. The segmented results offer an important clue for defect detection. Furthermore, incorrect segmentation because of intensity inhomogeneity can be minimized.</div></div>","PeriodicalId":13549,"journal":{"name":"Infrared Physics & Technology","volume":"146 ","pages":"Article 105754"},"PeriodicalIF":3.1,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Infrared maritime small target detection network based on attention and partial learning convolution","authors":"Enzhong Zhao,&nbsp;Lili Dong,&nbsp;Xinlei Chu,&nbsp;Mengge Wang","doi":"10.1016/j.infrared.2025.105748","DOIUrl":"10.1016/j.infrared.2025.105748","url":null,"abstract":"<div><div>Infrared maritime targets (IMTs) captured by infrared sensors lack distinct detailed features and have a low signal-to-noise ratio, which renders the detection of such targets more challenging than typical target detection tasks. To improve detection accuracy, this manuscript exploits the characteristics of IMTs and proposes a detection network based on attention and partial learning convolution (APLCnet). Firstly, a projected-global self-attention module (PGSAM) is designed based on the projected saliency of IMTs. By encoding long-range features, PGSAM effectively captures the contextual relationships between targets and their backgrounds. Secondly, an attention module based on the local-wide convolutional block attention module (LWCBAM) is devised. By introducing local attention and attention over a larger receptive field, this module helps the network highlight important spatial and channel features after feature fusion, preventing critical weak targets from being overwhelmed during the fusion process. Additionally, inspired by traditional edge detection operators, a partial learning convolutional module (PLCM) is designed and applied to shallow features, which enhances the focus on small IMTs, improving the saliency of weak and small IMTs. Experimental results demonstrate that the proposed network effectively improves the accuracy of IMT detection while maintaining higher robustness.</div></div>","PeriodicalId":13549,"journal":{"name":"Infrared Physics & Technology","volume":"146 ","pages":"Article 105748"},"PeriodicalIF":3.1,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Data processing method for multi-spectral radiometric thermometry based on IDPHGA","authors":"Hailong Liu ,&nbsp;Shan Gao ,&nbsp;Xinmeng Xiong ,&nbsp;Rongyan Gao ,&nbsp;Ming Liu ,&nbsp;Liwei Chen ,&nbsp;Tong Wang ,&nbsp;Ying Cui ,&nbsp;Min Ouyang ,&nbsp;Yixiao Zhen ,&nbsp;Chao Wang","doi":"10.1016/j.infrared.2025.105747","DOIUrl":"10.1016/j.infrared.2025.105747","url":null,"abstract":"<div><div>Oxidized high-temperature alloys are known for their excellent thermal properties in high-temperature environments, making them suitable for complex working conditions such as gas turbines and aero-engines. The temperature of oxidized alloys is measured to provide a more comprehensive reflection of their performance under actual working conditions, thereby offering important data support for engineering design and safety assessment. However, the accurate measurement of surface temperature when spectral emissivity is unknown remains a pressing challenge. At high temperatures or under extreme conditions, further changes may occur in the oxide layer, such as exfoliation and re-oxidation, which can affect its emissivity. Conventional methods that assume a emissivity model are unable to accurately accommodate these alterations. In response, an Improved Double-Population Hybrid Genetic Algorithm (IDPHGA) for multi-spectral radiometric thermometry is proposed in this paper, enabling the simultaneous estimation of temperature and emissivity of the oxidized samples without the need to assume an emissivity model. The temperature testing of oxidized GH3128, GH4037, GH4169, and GH536 samples across various temperature points was conducted utilizing the IDPHGA method, the average absolute temperature measurement errors obtained were not greater than 4.7 K, 4.7 K, 5.4 K, and 4.6 K, respectively. The experimental outcomes have verified that the method proposed in this paper possesses superior accuracy and robustness in the measurement of real objects. The validation is significant for promoting the extensive application of high-temperature alloy materials in the fields of aviation, navigation, and other high-temperature applications.</div></div>","PeriodicalId":13549,"journal":{"name":"Infrared Physics & Technology","volume":"146 ","pages":"Article 105747"},"PeriodicalIF":3.1,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Dual-wavelength twin-pulse laser with tunable intensity and delay at 912 nm & 1064 nm under intracavity gain-switched pumping","authors":"Jian Xu ,&nbsp;Yu Liu ,&nbsp;Yushi Jin ,&nbsp;Yongji Yu ,&nbsp;Long Jin ,&nbsp;Yuan Dong","doi":"10.1016/j.infrared.2025.105749","DOIUrl":"10.1016/j.infrared.2025.105749","url":null,"abstract":"<div><div>We report a dual-wavelength twin-pulse laser with tunable intensity and delay at 912 nm &amp; 1064 nm with compactly combined Nd:GdVO₄ and Nd:YVO₄ crystals under intracavity gain-switched pumping. According to reports, this system was the first to eliminate gain competition between 912 nm &amp; 1064 nm dual-wavelength twin-pulse laser. It also enabled intensity and delay control between the dual-wavelength twin-pulse by changing the absorbed pump power. The experimental findings revealed that the dual-wavelength twin-pulse laser attained the threshold of the absorbed pump power at 14.22 W. Further increasing the absorbed pump power, the intensity of the dual-wavelength twin-pulse increased, and the delay decreased accordingly. As a result, dual-wavelength twin-pulse with an intensity ratio of 0.89 to 1.37 and a delay of 21 ns to 7 ns were obtained. Under the maximum absorbed pump power of 16.77 W, the dual-wavelength twin-pulse laser achieved an average output power of 510 mW, with 215 mW for the 912 nm laser and 295 mW for the 1064 nm laser. The overall slope efficiency was 16.7 %. The maximum repetition rate was 30.07 kHz, the pulse width at 912 nm was 48.59 ns, and the pulse width at 1064 nm was 37.98 ns.</div></div>","PeriodicalId":13549,"journal":{"name":"Infrared Physics & Technology","volume":"146 ","pages":"Article 105749"},"PeriodicalIF":3.1,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143379020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}