Infrared Physics & Technology最新文献_第5页

Irst-RTDETR: An infrared small target detection and real-size estimation method based on improved RT-DETR and deep perception first - rtdetr：一种基于改进RT-DETR和深度感知的红外小目标检测和真实尺寸估计方法

IF 3.4 3区物理与天体物理 Q2 INSTRUMENTS & INSTRUMENTATION

Infrared Physics & Technology

Pub Date : 2026-01-15 DOI: 10.1016/j.infrared.2026.106403

Zhenlun Chen , Yuchen Zhang , Jianhua Qin , Heng Wang

Infrared image detection holds significant value in both military and civilian fields, but the detection accuracy is severely restricted by low contrast, low signal-to-noise ratio, and extremely small target sizes. Meanwhile, existing size estimation methods often rely on multi-view or multi-sensor approaches, which complicate the system and reduce real-time performance. Therefore, this paper proposes an efficient infrared small target detection and actual size estimation method—IRST-RTDETR. First, a global contrast perception-guided edge-adaptive sharpening preprocessing method (GCP-TEAS) is designed, which integrates global contrast and local edge information to enhance the boundaries of low-significance targets at the source. Subsequently, a novel cross-stage edge feature enhancement module (CSEFEM), multi-scale multi-head self-attention fusion module (MSMH-AIFI), and gated edge feature fusion module (GEFC3) are introduced into the detection network. These modules improve small target detail retention, edge representation, and robustness through edge enhancement, cross-scale modeling, and gated modulation, respectively. Finally, a real-time detection and actual size estimation system is constructed by combining the Intel D435i depth camera with the Jetson Orin NX platform. Experimental results show that IRST-RTDETR achieves F1 (mean) improvements over existing SOTA methods (including YOLO-MST, IRSTD-YOLO, CYSDM, ISTD-DETR, REDETR-ISTD, ACM, and AER-Net) by 0.5 %–22.8 %, 0.6 %–18.5 %, 1.7 %–10.8 %, and 0.6 %–20.1 % on the SIRST, SIRST-v2, IRSTD-1 K, and NUDT-SIRST datasets, respectively. [email protected] (mean) increases by 1.7 %–10.4 %, 0.9 %–8.3 %, 0.9 %–5.6 %, and 0.3 %–2.9 %; while [email protected]:0.95 (mean) improves by 1.1 %–10.3 %, 0.2 %–6.1 %, 0.8 %–7.2 %, and 2.4 %–12.8 %. Compared to baseline models, IRST-RTDETR boosts the FPS (mean) on the NX platform across the four datasets by 6.6, 6.5, 4.7, and 5.6, respectively, while reducing GFLOPs by 25.9 % and the number of parameters by 33.2 %. Moreover, the proposed system ensures real-time performance while exhibiting excellent cross-distance size estimation capabilities. This work achieves effective breakthroughs in improving the accuracy, real-time performance, and deployability of infrared dim and small target detection, offering an efficient and practically valuable solution for intelligent detection and target size perception in complex scenarios.

All codes and model weights are publicly available at: https://github.com/amumu77-lang/IRST-RTDETR.

红外图像检测在军事和民用领域都具有重要的应用价值，但低对比度、低信噪比和极小目标尺寸严重限制了检测精度。同时，现有的尺寸估计方法往往依赖于多视图或多传感器的方法，这使得系统复杂，降低了实时性。为此，本文提出了一种高效的红外小目标检测与实际尺寸估计方法——irst - rtdetr。首先，设计了一种全局对比度感知引导下的边缘自适应锐化预处理方法（GCP-TEAS），该方法将全局对比度和局部边缘信息相结合，增强了低显著性目标在源处的边界；随后，在检测网络中引入了新型的跨阶段边缘特征增强模块（CSEFEM）、多尺度多头自关注融合模块（MSMH-AIFI）和门控边缘特征融合模块（GEFC3）。这些模块分别通过边缘增强、跨尺度建模和门控调制来改善小目标细节保留、边缘表示和鲁棒性。最后，将Intel D435i深度相机与Jetson Orin NX平台相结合，构建了实时检测与实际尺寸估计系统。实验结果表明，在SIRST、SIRST-v2、irstd - 1k和NUDT-SIRST数据集上，IRST-RTDETR比现有的SOTA方法（包括ylo - mst、IRSTD-YOLO、CYSDM、ISTD-DETR、REDETR-ISTD、ACM和AER-Net）分别提高了0.5% - 22.8%、0.6% - 18.5%、1.7% - 10.8%和0.6% - 20.1%，达到了F1（平均）的改进。电子邮件保护(平均)增加1.7% - -10.4%,0.9%,-8.3%,0.9%,-5.6%,-2.9%和0.3%;而(邮件保护):0.95(平均)提高1.1% - -10.3%,0.2% - -6.1%,0.8% - -7.2%和2.4% - -12.8%。与基线模型相比，IRST-RTDETR在NX平台上的四个数据集上的FPS（平均）分别提高了6.6、6.5、4.7和5.6，而GFLOPs降低了25.9%，参数数量减少了33.2%。此外，该系统在保证实时性能的同时，还具有出色的跨距离大小估计能力。本工作在提高红外弱小目标检测精度、实时性和可部署性方面取得了有效突破，为复杂场景下的智能检测和目标尺寸感知提供了高效且具有实用价值的解决方案。所有代码和模型权重都可以在https://github.com/amumu77-lang/IRST-RTDETR上公开获得。

{"title":"Irst-RTDETR: An infrared small target detection and real-size estimation method based on improved RT-DETR and deep perception","authors":"Zhenlun Chen , Yuchen Zhang , Jianhua Qin , Heng Wang","doi":"10.1016/j.infrared.2026.106403","DOIUrl":"10.1016/j.infrared.2026.106403","url":null,"abstract":"<div><div>Infrared image detection holds significant value in both military and civilian fields, but the detection accuracy is severely restricted by low contrast, low signal-to-noise ratio, and extremely small target sizes. Meanwhile, existing size estimation methods often rely on multi-view or multi-sensor approaches, which complicate the system and reduce real-time performance. Therefore, this paper proposes an efficient infrared small target detection and actual size estimation method—IRST-RTDETR. First, a global contrast perception-guided edge-adaptive sharpening preprocessing method (GCP-TEAS) is designed, which integrates global contrast and local edge information to enhance the boundaries of low-significance targets at the source. Subsequently, a novel cross-stage edge feature enhancement module (CSEFEM), multi-scale multi-head self-attention fusion module (MSMH-AIFI), and gated edge feature fusion module (GEFC3) are introduced into the detection network. These modules improve small target detail retention, edge representation, and robustness through edge enhancement, cross-scale modeling, and gated modulation, respectively. Finally, a real-time detection and actual size estimation system is constructed by combining the Intel D435i depth camera with the Jetson Orin NX platform. Experimental results show that IRST-RTDETR achieves F1 (mean) improvements over existing SOTA methods (including YOLO-MST, IRSTD-YOLO, CYSDM, ISTD-DETR, REDETR-ISTD, ACM, and AER-Net) by 0.5 %–22.8 %, 0.6 %–18.5 %, 1.7 %–10.8 %, and 0.6 %–20.1 % on the SIRST, SIRST-v2, IRSTD-1 K, and NUDT-SIRST datasets, respectively. [email protected] (mean) increases by 1.7 %–10.4 %, 0.9 %–8.3 %, 0.9 %–5.6 %, and 0.3 %–2.9 %; while [email protected]:0.95 (mean) improves by 1.1 %–10.3 %, 0.2 %–6.1 %, 0.8 %–7.2 %, and 2.4 %–12.8 %. Compared to baseline models, IRST-RTDETR boosts the FPS (mean) on the NX platform across the four datasets by 6.6, 6.5, 4.7, and 5.6, respectively, while reducing GFLOPs by 25.9 % and the number of parameters by 33.2 %. Moreover, the proposed system ensures real-time performance while exhibiting excellent cross-distance size estimation capabilities. This work achieves effective breakthroughs in improving the accuracy, real-time performance, and deployability of infrared dim and small target detection, offering an efficient and practically valuable solution for intelligent detection and target size perception in complex scenarios.</div><div>All codes and model weights are publicly available at: <span><span>https://github.com/amumu77-lang/IRST-RTDETR</span><svg><path></path></svg></span>.</div></div>","PeriodicalId":13549,"journal":{"name":"Infrared Physics & Technology","volume":"154 ","pages":"Article 106403"},"PeriodicalIF":3.4,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146023732","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}

引用次数: 0

Effect of the size of ε-Fe2O3 nanoparticles embedded in SiO2 silica gel and xerogel matrices on the features in FTIR spectra SiO2硅胶和干凝胶基质中ε-Fe2O3纳米颗粒尺寸对FTIR光谱特征的影响

IF 3.4 3区物理与天体物理 Q2 INSTRUMENTS & INSTRUMENTATION

Infrared Physics & Technology

Pub Date : 2026-01-14 DOI: 10.1016/j.infrared.2026.106387

Yulia V. Pyastolova , Anastasia A. Marchenko , Felix N. Tomilin , Andrey A. Dubrovskiy , Dmitry A. Balaev , Oleg N. Martyanov

The spectral properties of ε-Fe₂O₃ nanoparticles of different sizes embedded in SiO₂ silica gel and xerogel matrices have been investigated by vibrational spectroscopy in the frequency range of 380‒4000 cm^‒1. The experimental data have been interpreted using the density functional theory calculation of the ε-Fe₂O₃ structure and phonon modes and the results obtained for the crystal, electronic, and vibrational structure have been found to agree well. Analysis of the dynamics of the spectra has shown that the main contribution to the IR spectra of ε-Fe₂O₃ nanoparticles in SiO₂ silica gel and xerogel matrices is made by bending vibrations of the FeOFe bond in the octahedron and tetrahedron. It has been established that the fraction of hydrogen bonds for nanoparticles with an average size of ∼2 nm is greater than for coarser particles. With an increase in the nanoparticle size, the crystallinity of nanoparticles grows.

用振动谱法研究了不同粒径的ε-Fe2O3纳米颗粒在SiO2硅胶和干凝胶基质中的光谱特性。用密度泛函理论计算ε-Fe2O3的结构和声子模式，对实验数据进行了解释，得到了晶体结构、电子结构和振动结构的一致结果。光谱动力学分析表明，ε-Fe2O3纳米颗粒在SiO2硅胶和干凝胶基质中的红外光谱主要是由八面体和四面体中FeOFe键的弯曲振动产生的。已经确定，平均尺寸为~ 2 nm的纳米颗粒的氢键分数大于粗颗粒。随着纳米颗粒尺寸的增大，纳米颗粒的结晶度增大。

{"title":"Effect of the size of ε-Fe2O3 nanoparticles embedded in SiO2 silica gel and xerogel matrices on the features in FTIR spectra","authors":"Yulia V. Pyastolova , Anastasia A. Marchenko , Felix N. Tomilin , Andrey A. Dubrovskiy , Dmitry A. Balaev , Oleg N. Martyanov","doi":"10.1016/j.infrared.2026.106387","DOIUrl":"10.1016/j.infrared.2026.106387","url":null,"abstract":"<div><div>The spectral properties of ε-Fe<sub>2</sub>O<sub>3</sub> nanoparticles of different sizes embedded in SiO<sub>2</sub> silica gel and xerogel matrices have been investigated by vibrational spectroscopy in the frequency range of 380‒4000 cm<sup>‒1</sup>. The experimental data have been interpreted using the density functional theory calculation of the ε-Fe<sub>2</sub>O<sub>3</sub> structure and phonon modes and the results obtained for the crystal, electronic, and vibrational structure have been found to agree well. Analysis of the dynamics of the spectra has shown that the main contribution to the IR spectra of ε-Fe<sub>2</sub>O<sub>3</sub> nanoparticles in SiO<sub>2</sub> silica gel and xerogel matrices is made by bending vibrations of the Fe<img>O<img>Fe bond in the octahedron and tetrahedron. It has been established that the fraction of hydrogen bonds for nanoparticles with an average size of ∼2 nm is greater than for coarser particles. With an increase in the nanoparticle size, the crystallinity of nanoparticles grows.</div></div>","PeriodicalId":13549,"journal":{"name":"Infrared Physics & Technology","volume":"154 ","pages":"Article 106387"},"PeriodicalIF":3.4,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146023689","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}

引用次数: 0

HR-YOLO: Enhanced YOLO framework for infrared-based timber component damage detection in heritage arch lounge bridges HR-YOLO：基于红外的传统拱廊桥木材构件损伤检测的增强YOLO框架

IF 3.4 3区物理与天体物理 Q2 INSTRUMENTS & INSTRUMENTATION

Infrared Physics & Technology

Pub Date : 2026-01-14 DOI: 10.1016/j.infrared.2026.106401

Zhiqiang Qin , Qifang Xie , Zheng Li

This study proposes an infrared imaging-based damage detection method for ancient Chinese timber arch lounge bridges using an improved YOLO11 model. Three datasets were established for damage detection scenarios involving general timber components and heritage timber arch lounge bridge components. Although the YOLO11 model achieved good performance after hyperparameter optimization in general timber components detection task (69.3% on cracks; 63.2% on multi-damage), its precision dropped significantly in heritage timber arch lounge bridge scenarios due to small targets and complex backgrounds. A transfer learning strategy was adopted to overcome this limitation, which enhanced training stability and detection precision for heritage bridge damage detection. Moreover, Non-local Attention Mechanism and SimAM were integrated into the YOLO11 architecture to improve the model performance over three datasets. Detection results demonstrated that the Non-local Attention Mechanism achieves higher precision and is more suitable for infrared video detection tasks compared to the baseline model. SimAM exhibits significant lightweight characteristics while maintaining great precision. Finally, we outline a practical UAV-based inspection workflow that couples infrared data acquisition with real-time HR-YOLO inference to support repeatable, field-ready monitoring of heritage timber bridges. This research offers an automated solution for real-time structural health monitoring of cultural heritage, promoting the application of intelligent infrared detection techniques in heritage preservation and civil engineering.

本研究提出了一种基于红外成像的中国古代木拱廊桥损伤检测方法，该方法采用改进的YOLO11模型。建立了普通木材构件和传统木材拱廊桥构件损伤检测场景的3个数据集。尽管经过超参数优化后的YOLO11模型在一般木材构件检测任务中取得了较好的性能（裂缝检测69.3%，多损伤检测63.2%），但在传统木拱桥场景中，由于目标小、背景复杂，其精度明显下降。采用迁移学习策略克服了这一局限性，提高了传统桥梁损伤检测的训练稳定性和检测精度。此外，将非局部注意机制和SimAM集成到YOLO11体系结构中，提高了模型在三个数据集上的性能。检测结果表明，与基线模型相比，非局部注意机制具有更高的检测精度，更适合红外视频检测任务。SimAM具有显著的轻量化特性，同时保持极高的精度。最后，我们概述了一种实用的基于无人机的检测工作流程，该流程将红外数据采集与实时HR-YOLO推断相结合，以支持对传统木桥进行可重复的现场监测。本研究为文物结构健康实时监测提供了自动化解决方案，促进了智能红外探测技术在文物保护和土木工程中的应用。

{"title":"HR-YOLO: Enhanced YOLO framework for infrared-based timber component damage detection in heritage arch lounge bridges","authors":"Zhiqiang Qin , Qifang Xie , Zheng Li","doi":"10.1016/j.infrared.2026.106401","DOIUrl":"10.1016/j.infrared.2026.106401","url":null,"abstract":"<div><div>This study proposes an infrared imaging-based damage detection method for ancient Chinese timber arch lounge bridges using an improved YOLO11 model. Three datasets were established for damage detection scenarios involving general timber components and heritage timber arch lounge bridge components. Although the YOLO11 model achieved good performance after hyperparameter optimization in general timber components detection task (69.3% on cracks; 63.2% on multi-damage), its precision dropped significantly in heritage timber arch lounge bridge scenarios due to small targets and complex backgrounds. A transfer learning strategy was adopted to overcome this limitation, which enhanced training stability and detection precision for heritage bridge damage detection. Moreover, Non-local Attention Mechanism and SimAM were integrated into the YOLO11 architecture to improve the model performance over three datasets. Detection results demonstrated that the Non-local Attention Mechanism achieves higher precision and is more suitable for infrared video detection tasks compared to the baseline model. SimAM exhibits significant lightweight characteristics while maintaining great precision. Finally, we outline a practical UAV-based inspection workflow that couples infrared data acquisition with real-time HR-YOLO inference to support repeatable, field-ready monitoring of heritage timber bridges. This research offers an automated solution for real-time structural health monitoring of cultural heritage, promoting the application of intelligent infrared detection techniques in heritage preservation and civil engineering.</div></div>","PeriodicalId":13549,"journal":{"name":"Infrared Physics & Technology","volume":"154 ","pages":"Article 106401"},"PeriodicalIF":3.4,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146023731","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}

引用次数: 0

Multimodal online monitoring of laser melt pool based on polarized infrared spectral imaging 基于偏振红外光谱成像的激光熔池多模态在线监测

IF 3.4 3区物理与天体物理 Q2 INSTRUMENTS & INSTRUMENTATION

Infrared Physics & Technology

Pub Date : 2026-01-14 DOI: 10.1016/j.infrared.2026.106404

Xianjin Kong, Guibo Chen, Ye Zhang

This study proposes a multimodal diagnostic approach that integrates infrared polarization spectroscopy imaging, spectral temperature inversion, and numerical simulation to investigate the dynamic evolution of melt pool behavior during laser processing. A near-infrared polarization imaging system was employed to achieve real-time observation of the melt pool interface and morphological evolution. By incorporating the multispectral thermometry (MST) method, temperature reconstruction was conducted, revealing a strong spatial correlation between the saturated regions in the degree of linear polarization (DOLP) images and localized high-temperature zones. To address the limitation of polarization imaging in capturing melt pool depth, a multiphysics model incorporating key mechanical mechanisms was established to analyze the coupled evolution of temperature and flow fields and to support interface morphology interpretation. Experimental results demonstrate that the interface contours extracted from DOLP images closely match the boundaries observed in thermal imaging, with deviations between experimental observations and numerical predictions remaining below 10%. In the quasi-steady-state regime, interfacial driving force analysis indicates that recoil pressure predominantly governs the formation of interfacial depressions, while Marangoni forces control the recirculation of molten metal and the flattening of edge morphology. Furthermore, the study reveals nonlinear thermal and morphological responses of the melt pool under varying combinations of pulse width and repetition rate. The integrated experimental–numerical framework developed in this work enables melt-pool behavior identification and mechanism interpretation, and provides a foundation for predictive analysis of interface evolution, offering a systematic basis for understanding interfacial dynamics in laser processing.

本研究提出了一种集成红外偏振光谱成像、光谱温度反演和数值模拟的多模态诊断方法，以研究激光加工过程中熔池行为的动态演变。采用近红外偏振成像系统对熔池界面和形态演变进行实时观测。结合多光谱测温（MST）方法进行温度重建，发现线偏振度（DOLP）图像中的饱和区域与局部高温区之间存在较强的空间相关性。为了解决极化成像在捕捉熔池深度方面的局限性，建立了包含关键力学机制的多物理场模型，分析了温度场和流场的耦合演化，并支持界面形态解释。实验结果表明，从DOLP图像中提取的界面轮廓与热成像中观测到的边界吻合较好，实验观测值与数值预测值的偏差小于10%。在准稳态状态下，界面驱动力分析表明，反冲压力主要控制界面凹陷的形成，而Marangoni力主要控制熔融金属的再循环和边缘形貌的平坦化。此外，研究还揭示了不同脉冲宽度和重复频率组合下熔池的非线性热响应和形态响应。本研究开发的综合实验-数值框架使熔池行为识别和机制解释成为可能，并为界面演变的预测分析奠定了基础，为理解激光加工中的界面动力学提供了系统的基础。

{"title":"Multimodal online monitoring of laser melt pool based on polarized infrared spectral imaging","authors":"Xianjin Kong, Guibo Chen, Ye Zhang","doi":"10.1016/j.infrared.2026.106404","DOIUrl":"10.1016/j.infrared.2026.106404","url":null,"abstract":"<div><div>This study proposes a multimodal diagnostic approach that integrates infrared polarization spectroscopy imaging, spectral temperature inversion, and numerical simulation to investigate the dynamic evolution of melt pool behavior during laser processing. A near-infrared polarization imaging system was employed to achieve real-time observation of the melt pool interface and morphological evolution. By incorporating the multispectral thermometry (MST) method, temperature reconstruction was conducted, revealing a strong spatial correlation between the saturated regions in the degree of linear polarization (DOLP) images and localized high-temperature zones. To address the limitation of polarization imaging in capturing melt pool depth, a multiphysics model incorporating key mechanical mechanisms was established to analyze the coupled evolution of temperature and flow fields and to support interface morphology interpretation. Experimental results demonstrate that the interface contours extracted from DOLP images closely match the boundaries observed in thermal imaging, with deviations between experimental observations and numerical predictions remaining below 10%. In the quasi-steady-state regime, interfacial driving force analysis indicates that recoil pressure predominantly governs the formation of interfacial depressions, while Marangoni forces control the recirculation of molten metal and the flattening of edge morphology. Furthermore, the study reveals nonlinear thermal and morphological responses of the melt pool under varying combinations of pulse width and repetition rate. The integrated experimental–numerical framework developed in this work enables melt-pool behavior identification and mechanism interpretation, and provides a foundation for predictive analysis of interface evolution, offering a systematic basis for understanding interfacial dynamics in laser processing.</div></div>","PeriodicalId":13549,"journal":{"name":"Infrared Physics & Technology","volume":"154 ","pages":"Article 106404"},"PeriodicalIF":3.4,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146023739","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}

引用次数: 0

A novel encoded line laser array method of scanning infrared thermography nondestructive testing for CFRP defect 一种新型编码线激光阵列扫描红外热成像CFRP缺陷无损检测方法

IF 3.4 3区物理与天体物理 Q2 INSTRUMENTS & INSTRUMENTATION

Infrared Physics & Technology

Pub Date : 2026-01-14 DOI: 10.1016/j.infrared.2026.106397

Rui Li , Di Wu , Yunsheng An , Yucai Xie , Hongpeng Zhang , Jizhe Wang , Wei Li , Chenzhao Bai , Chenyong Wang , Li Sun

This paper presents a novel encoded line laser array (ELLA) method for scanning infrared thermography nondestructive testing (IRT‑NDT) of carbon fiber reinforced plastics (CFRP). By spatially arranging multiple line lasers, ELLA generates Lock‑in like, frequency‑modulation like, and 13‑bit Barker‑coded pulse like (Barker13‑like) excitation waveforms, extending modulated thermography from static to scanning systems. Numerical simulations confirmed that ELLA heating profiles closely match static excitations. To process dynamic image sequences, pseudo‑static matrix reconstruction (PSMR) converts them into spatially static datasets, enabling established algorithms such as fast Fourier transform, thermal signal reconstruction, and matched filtering (MF). The algorithmic results demonstrated that, compared with single line laser scanning, the combination of ELLA with PSMR and post‑processing effectively improves defect detectability, even under added salt‑and‑pepper and Gaussian noise. Both the signal‑to‑clutter ratio and signal‑to‑noise ratio (SNR) evaluations confirm the effectiveness of ELLA, with overall values being improved by post‑processing algorithms. Barker13‑like excitation achieves consistently high SNR across most algorithms, and the moving average model of MF reached the maximum SNR of 12.91. Overall, ELLA integrates the rapid coverage of scanning IRT‑NDT with the sensitivity of modulated excitation, offering a feasible and efficient approach for large‑scale CFRP defect detection.

提出了一种用于碳纤维增强塑料（CFRP）扫描红外热成像无损检测（IRT - NDT）的新型编码线激光阵列（ELLA）方法。通过在空间上安排多行激光器，ELLA产生类似锁相、频率调制和13位巴克编码脉冲（类似巴克13）的激励波形，将调制热成像从静态扩展到扫描系统。数值模拟证实了ELLA的加热分布与静态激励密切匹配。为了处理动态图像序列，伪静态矩阵重构（PSMR）将其转换为空间静态数据集，从而实现快速傅立叶变换、热信号重构和匹配滤波（MF）等已建立的算法。算法结果表明，与单线激光扫描相比，ELLA与PSMR和后处理相结合，即使在添加盐和胡椒和高斯噪声的情况下，也能有效提高缺陷的可检测性。信杂波比和信噪比（SNR）评估都证实了ELLA的有效性，并且通过后处理算法提高了总体值。Barker13 - like激励在大多数算法中都获得了一致的高信噪比，并且MF的移动平均模型达到了12.91的最大信噪比。总的来说，ELLA结合了扫描IRT - NDT的快速覆盖和调制激励的灵敏度，为大规模CFRP缺陷检测提供了一种可行而有效的方法。

{"title":"A novel encoded line laser array method of scanning infrared thermography nondestructive testing for CFRP defect","authors":"Rui Li , Di Wu , Yunsheng An , Yucai Xie , Hongpeng Zhang , Jizhe Wang , Wei Li , Chenzhao Bai , Chenyong Wang , Li Sun","doi":"10.1016/j.infrared.2026.106397","DOIUrl":"10.1016/j.infrared.2026.106397","url":null,"abstract":"<div><div>This paper presents a novel encoded line laser array (ELLA) method for scanning infrared thermography nondestructive testing (IRT‑NDT) of carbon fiber reinforced plastics (CFRP). By spatially arranging multiple line lasers, ELLA generates Lock‑in like, frequency‑modulation like, and 13‑bit Barker‑coded pulse like (Barker13‑like) excitation waveforms, extending modulated thermography from static to scanning systems. Numerical simulations confirmed that ELLA heating profiles closely match static excitations. To process dynamic image sequences, pseudo‑static matrix reconstruction (PSMR) converts them into spatially static datasets, enabling established algorithms such as fast Fourier transform, thermal signal reconstruction, and matched filtering (MF). The algorithmic results demonstrated that, compared with single line laser scanning, the combination of ELLA with PSMR and post‑processing effectively improves defect detectability, even under added salt‑and‑pepper and Gaussian noise. Both the signal‑to‑clutter ratio and signal‑to‑noise ratio (SNR) evaluations confirm the effectiveness of ELLA, with overall values being improved by post‑processing algorithms. Barker13‑like excitation achieves consistently high SNR across most algorithms, and the moving average model of MF reached the maximum SNR of 12.91. Overall, ELLA integrates the rapid coverage of scanning IRT‑NDT with the sensitivity of modulated excitation, offering a feasible and efficient approach for large‑scale CFRP defect detection.</div></div>","PeriodicalId":13549,"journal":{"name":"Infrared Physics & Technology","volume":"154 ","pages":"Article 106397"},"PeriodicalIF":3.4,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146074068","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}

引用次数: 0

Spectral clustering dimensionality reduction in wheat quality detection based on hyperspectral data 基于高光谱数据的小麦品质检测光谱聚类降维

IF 3.4 3区物理与天体物理 Q2 INSTRUMENTS & INSTRUMENTATION

Infrared Physics & Technology

Pub Date : 2026-01-14 DOI: 10.1016/j.infrared.2026.106400

Huawei Jiang , Yiduo Zhu , Wanbao Sheng , Ruomeng Hu , Wenqiang Pi , Zhen Yang , Like Zhao

As one of the most important food crops worldwide, the accurate quality detection of wheat is a key link in safeguarding food security and food safety. Hyperspectral technology, as an effective method for quality detection, however, faces challenges in accurately determining critical quality indicators such as wheat deterioration degree due to the presence of massive redundant information. To address this issue, this study proposes a Spectral Clustering Dimensionality Reduction (SCDR) algorithm that integrates spectral angle similarity and spatial distance. First, the differences and similarities among various spectral features are quantitatively analyzed to construct the feature relationships between different bands. Second, based on these feature relationships, high-dimensional features are partitioned via clustering to generate feature clusters with dimensions far lower than those of the original data. Finally, weights are assigned according to the intra-cluster feature differences and similarities to calculate the representative feature values, thereby achieving dimensionality reduction. The experimental results demonstrate that the wheat quality detection model established based on the SCDR algorithm achieves an accuracy, precision, recall and F1-score of 0.9821, 0.9818, 0.9822 and 0.9818, respectively, on the test set, and its performance is significantly superior to that of other comparative models.

小麦作为世界上最重要的粮食作物之一，准确的质量检测是保障粮食安全和食品安全的关键环节。然而，高光谱技术作为一种有效的品质检测方法，由于存在大量冗余信息，在准确确定小麦变质程度等关键品质指标方面面临挑战。为了解决这一问题，本研究提出了一种融合光谱角相似度和空间距离的光谱聚类降维算法。首先，定量分析各种光谱特征之间的异同，构建不同波段之间的特征关系；其次，基于这些特征关系，对高维特征进行聚类分割，生成远低于原始数据维数的特征聚类；最后，根据聚类内特征的相似度和差异分配权重，计算具有代表性的特征值，从而实现降维。实验结果表明，基于SCDR算法建立的小麦品质检测模型在测试集上的准确率、精密度、召回率和f1分数分别为0.9821、0.9818、0.9822和0.9818，其性能明显优于其他比较模型。

{"title":"Spectral clustering dimensionality reduction in wheat quality detection based on hyperspectral data","authors":"Huawei Jiang , Yiduo Zhu , Wanbao Sheng , Ruomeng Hu , Wenqiang Pi , Zhen Yang , Like Zhao","doi":"10.1016/j.infrared.2026.106400","DOIUrl":"10.1016/j.infrared.2026.106400","url":null,"abstract":"<div><div>As one of the most important food crops worldwide, the accurate quality detection of wheat is a key link in safeguarding food security and food safety. Hyperspectral technology, as an effective method for quality detection, however, faces challenges in accurately determining critical quality indicators such as wheat deterioration degree due to the presence of massive redundant information. To address this issue, this study proposes a Spectral Clustering Dimensionality Reduction (SCDR) algorithm that integrates spectral angle similarity and spatial distance. First, the differences and similarities among various spectral features are quantitatively analyzed to construct the feature relationships between different bands. Second, based on these feature relationships, high-dimensional features are partitioned via clustering to generate feature clusters with dimensions far lower than those of the original data. Finally, weights are assigned according to the intra-cluster feature differences and similarities to calculate the representative feature values, thereby achieving dimensionality reduction. The experimental results demonstrate that the wheat quality detection model established based on the SCDR algorithm achieves an accuracy, precision, recall and F1-score of 0.9821, 0.9818, 0.9822 and 0.9818, respectively, on the test set, and its performance is significantly superior to that of other comparative models.</div></div>","PeriodicalId":13549,"journal":{"name":"Infrared Physics & Technology","volume":"154 ","pages":"Article 106400"},"PeriodicalIF":3.4,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146023733","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}

引用次数: 0

Detection of FRP-timber interfacial defects by movable array infrared thermography 可移动阵列红外热像仪检测frp -木材界面缺陷

IF 3.4 3区物理与天体物理 Q2 INSTRUMENTS & INSTRUMENTATION

Infrared Physics & Technology

Pub Date : 2026-01-14 DOI: 10.1016/j.infrared.2026.106399

Xingxing Zou , Md Mosfikur Rohan , Haitao Li

This study proposes a movable array infrared thermography (IRT) as an efficient non-destructive testing (NDT) method to detect interfacial defects between fiber-reinforced polymer (FRP) composites and timber. Firstly, multi-physics numerical simulations were conducted, which agreed well with experimental thermal response. Next, the proposed array IRT system was used to test eight FRP-timber specimens, which showed defects can be identified in 1 s, and accurately visualized in 6 s. Lastly, an actual 12-m-long laminated bamboo lumbe bridge with four joints strengthened by FRP cloth was detected using the proposed array IRT system in a movable mode. Results showed that while sunlight exposure and tree shade can lead to uneven spatial temperature distribution and localized overheating, all interfacial defects were successfully detected by the movable array IRT system.

本研究提出了一种可移动阵列红外热像仪（IRT）作为一种有效的无损检测（NDT）方法来检测纤维增强聚合物（FRP）复合材料与木材之间的界面缺陷。首先进行了多物理场数值模拟，结果与实验热响应吻合较好。接下来，利用阵列IRT系统对8个frp木材样品进行了测试，结果表明，缺陷可以在1 s内识别出来，并在6 s内准确地显示出来。最后，在可移动模式下，使用阵列IRT系统检测了一座实际的12米长、四个接缝由FRP布加固的叠层竹材桥。结果表明，虽然光照和遮荫会导致空间温度分布不均匀和局部过热，但可移动阵列红外热成像系统能够成功检测出所有界面缺陷。

引用次数: 0

Regulatory mechanism of self-emission and radiation reflection in Al/polysiloxane coatings with low infrared emissivity 低红外发射率铝/聚硅氧烷涂层自发射和辐射反射的调控机制

IF 3.4 3区物理与天体物理 Q2 INSTRUMENTS & INSTRUMENTATION

Infrared Physics & Technology

Pub Date : 2026-01-14 DOI: 10.1016/j.infrared.2026.106395

Lun Qi , Houjun Du , Ke Ren , Lei Zhang , Min Zhang , Xiaolong Weng , Le Yuan

In this study, the surface self-emission and reflected radiation characteristics of the coatings were effectively regulated using aluminum (Al) flake particles and sandblasted substrates. The effects and mechanisms of Al powder particle size and content on coating reflectance in hemispherical and three-dimensional (3D) spaces were systematically investigated. The hemispherical test results show that self-emission suppresses with the increase in Al particle size and Al/polysiloxane mass ratio owing to a gradual decrease in infrared emissivity. However, the specular reflection intensity in the 3D space first decreases and then increases, which is a result of increased surface roughness of coatings that further decreases with the increase of Al powder content. In addition, the disorder in the spatial distribution of larger Al particles became more pronounced, while the specular reflection intensity decreased as a result of reduced edge scattering from the particles. Consequently, the infrared radiation temperature of the coatings with high-roughness substrates was approximately 7 °C lower than that of the coatings with smooth substrates at sample and ambient temperatures of (25 ± 0.5) °C and (50 ± 0.5) °C, respectively. This is of great significance for the regulation of infrared radiation on a target surface.

在本研究中，采用铝（Al）片状颗粒和喷砂基材有效地调节了涂层的表面自发射和反射辐射特性。系统研究了Al粉粒度和含量对涂层半球形和三维空间反射率的影响及其机理。半球形测试结果表明，随着Al颗粒尺寸和Al/聚硅氧烷质量比的增加，红外发射率逐渐降低，自发射受到抑制。然而，三维空间的镜面反射强度先减小后增大，这是涂层表面粗糙度增大的结果，随着Al粉含量的增加，涂层表面粗糙度进一步减小。此外，较大的Al颗粒空间分布的无序性变得更加明显，而由于颗粒边缘散射的减少，镜面反射强度降低。因此，在样品温度为（25±0.5）℃和环境温度为（50±0.5）℃时，高粗糙度基底涂层的红外辐射温度比光滑基底涂层低约7℃。这对目标表面红外辐射的调控具有重要意义。

{"title":"Regulatory mechanism of self-emission and radiation reflection in Al/polysiloxane coatings with low infrared emissivity","authors":"Lun Qi , Houjun Du , Ke Ren , Lei Zhang , Min Zhang , Xiaolong Weng , Le Yuan","doi":"10.1016/j.infrared.2026.106395","DOIUrl":"10.1016/j.infrared.2026.106395","url":null,"abstract":"<div><div>In this study, the surface self-emission and reflected radiation characteristics of the coatings were effectively regulated using aluminum (Al) flake particles and sandblasted substrates. The effects and mechanisms of Al powder particle size and content on coating reflectance in hemispherical and three-dimensional (3D) spaces were systematically investigated. The hemispherical test results show that self-emission suppresses with the increase in Al particle size and Al/polysiloxane mass ratio owing to a gradual decrease in infrared emissivity. However, the specular reflection intensity in the 3D space first decreases and then increases, which is a result of increased surface roughness of coatings that further decreases with the increase of Al powder content. In addition, the disorder in the spatial distribution of larger Al particles became more pronounced, while the specular reflection intensity decreased as a result of reduced edge scattering from the particles. Consequently, the infrared radiation temperature of the coatings with high-roughness substrates was approximately 7 °C lower than that of the coatings with smooth substrates at sample and ambient temperatures of (25 ± 0.5) °C and (50 ± 0.5) °C, respectively. This is of great significance for the regulation of infrared radiation on a target surface.</div></div>","PeriodicalId":13549,"journal":{"name":"Infrared Physics & Technology","volume":"154 ","pages":"Article 106395"},"PeriodicalIF":3.4,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146023741","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}

引用次数: 0

A composite metasurface for infrared suppression and microwave absorption based on fresnel reflection 一种基于菲涅耳反射的红外抑制和微波吸收复合超表面

IF 3.4 3区物理与天体物理 Q2 INSTRUMENTS & INSTRUMENTATION

Infrared Physics & Technology

Pub Date : 2026-01-13 DOI: 10.1016/j.infrared.2026.106396

Mengke Qiao , Yuyao Tan , Pingan Chen , Yingli Zhu , Fu Chen , Jiang Wu , Xiangcheng Li

As an artificial functional material, electromagnetic metasurfaces possess a unique ability to manipulate electromagnetic waves, enabling infrared radiation suppression and microwave absorption to ensure reliable signal communication in complex environments. However, the development of multifunctional metasurfaces compatible across these bands is hindered by significant computational challenges. These arise from the vast disparity between sub-microwave structural dimensions and typical infrared wavelengths, requiring simulations to handle an extremely wide range of scales. To overcome this bottleneck, this paper proposes a Rapid Calculation Method (RCM) based on Fresnel reflection. The RCM directly utilizes the complex refractive indices of the constituent materials to compute the spectral emissivity, thereby dramatically enhancing the efficiency and accuracy of evaluating IR performance. Furthermore, an infrared-microwave compatible metasurface composite material is designed. This composite leverages the synergistic effects of an Infrared Suppression Layer (IRSL) and a Microwave Absorption Layer (MAL), achieving over 90% microwave absorption in the X&K_u bands and a low average emissivity of approximately 0.2 within the 3-14 μm range. Notably, this is accomplished with an ultra-thin total thickness of merely 0.083λ (where λ is the wavelength in the corresponding band). Experimental results show excellent agreement with simulation results. This work provides a novel computational tool and a new design paradigm for developing advanced multifunctional metasurface composites.

作为一种人工功能材料，电磁超表面具有独特的电磁波操纵能力，能够抑制红外辐射和吸收微波，确保在复杂环境下可靠的信号通信。然而，跨这些波段兼容的多功能元表面的发展受到重大计算挑战的阻碍。这是由于亚微波结构尺寸和典型红外波长之间的巨大差异，需要模拟来处理极宽范围的尺度。为了克服这一瓶颈，本文提出了一种基于菲涅耳反射的快速计算方法。RCM直接利用组成材料的复折射率来计算光谱发射率，从而大大提高了评估红外性能的效率和准确性。在此基础上，设计了一种红外微波兼容的超表面复合材料。该复合材料利用红外抑制层（IRSL）和微波吸收层（MAL）的协同效应，在X&；Ku波段实现90%以上的微波吸收，在3-14 μm范围内平均发射率约为0.2。值得注意的是，这是通过仅0.083λ的超薄总厚度完成的（其中λ是相应波段中的波长）。实验结果与仿真结果吻合良好。这项工作为开发先进的多功能超表面复合材料提供了一种新的计算工具和新的设计范式。

{"title":"A composite metasurface for infrared suppression and microwave absorption based on fresnel reflection","authors":"Mengke Qiao , Yuyao Tan , Pingan Chen , Yingli Zhu , Fu Chen , Jiang Wu , Xiangcheng Li","doi":"10.1016/j.infrared.2026.106396","DOIUrl":"10.1016/j.infrared.2026.106396","url":null,"abstract":"<div><div>As an artificial functional material, electromagnetic metasurfaces possess a unique ability to manipulate electromagnetic waves, enabling infrared radiation suppression and microwave absorption to ensure reliable signal communication in complex environments. However, the development of multifunctional metasurfaces compatible across these bands is hindered by significant computational challenges. These arise from the vast disparity between sub-microwave structural dimensions and typical infrared wavelengths, requiring simulations to handle an extremely wide range of scales. To overcome this bottleneck, this paper proposes a Rapid Calculation Method (RCM) based on Fresnel reflection. The RCM directly utilizes the complex refractive indices of the constituent materials to compute the spectral emissivity, thereby dramatically enhancing the efficiency and accuracy of evaluating IR performance. Furthermore, an infrared-microwave compatible metasurface composite material is designed. This composite leverages the synergistic effects of an Infrared Suppression Layer (IRSL) and a Microwave Absorption Layer (MAL), achieving over 90% microwave absorption in the X&K<sub>u</sub> <!-->bands and a low average emissivity of approximately 0.2 within the 3-14 μm range. Notably, this is accomplished with an ultra-thin total thickness of merely 0.083λ (where λ is the wavelength in the corresponding band). Experimental results show excellent agreement with simulation results. This work provides a novel computational tool and a new design paradigm for developing advanced multifunctional metasurface composites.</div></div>","PeriodicalId":13549,"journal":{"name":"Infrared Physics & Technology","volume":"154 ","pages":"Article 106396"},"PeriodicalIF":3.4,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974745","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}

引用次数: 0

An optical parametric oscillator based on BaGa2GeS6 with energy exceeding 2 mJ at 6.45 μm 基于BaGa2GeS6的6.45 μm能量超过2 mJ的光学参量振荡器

IF 3.4 3区物理与天体物理 Q2 INSTRUMENTS & INSTRUMENTATION

Infrared Physics & Technology

Pub Date : 2026-01-11 DOI: 10.1016/j.infrared.2026.106393

E.Yu. Erushin , S.E. Sere , M.V. Vostrikova , A.A. Boyko , G.S. Shevyrdyaeva , D.V. Badikov , A.A. Karapuzikov , N.Yu. Kostyukova

A high-energy optical parametric oscillator (OPO) based on a BaGa₂GeS₆ (BGGS) nonlinear crystal pumped by a home-built Q-switched Nd:YAG laser operating at 1064 nm with 15 ns pulse duration and 10 Hz repetition rate was demonstrated and characterized. The system generated idler radiation near 6.45 μm with a maximum pump-to-idler conversion efficiency of 2.23 % at a pump energy of 92 mJ, corresponding to an idler output energy of 2.06 mJ. Over an hour monitoring period, the output energy stability was 1.9 % RMS, and the average beam quality factor was M² was determined to be 33 at a pump energy of 85 mJ. The phase-matching characteristics were experimentally studied via angular tuning of the BGGS crystal, and refined Sellmeier coefficients for the ordinary and extraordinary refractive indices were obtained using a least-squares fit, reducing the error between theory and experiment to 0.1°. The idler spectral linewidth, estimated by convolution of the measured pump and signal spectra, was 63.5 nm. The findings suggest that the BGGS crystal represents a promising nonlinear optical material for the generation of high-energy radiation within the mid-infrared spectral range.

在国产调q Nd:YAG激光器的泵浦下，以1064 nm、15 ns脉冲持续时间和10 Hz重复频率，制备了基于BaGa2GeS6 （BGGS）非线性晶体的高能光学参量振荡器（OPO）。当泵能量为92 mJ时，系统产生的闲散辐射在6.45 μm附近，最大泵-闲散转换效率为2.23%，对应于闲散输出能量为2.06 mJ。在一个小时的监测期间，输出能量稳定性为1.9% RMS，在泵浦能量为85 mJ时，确定了平均光束质量因子M2为33。通过角调谐实验研究了BGGS晶体的相位匹配特性，并利用最小二乘拟合得到了普通折射率和特殊折射率的精细塞尔梅尔系数，将理论与实验的误差减小到0.1°。通过对测量的泵浦光谱和信号光谱的卷积估计，空闲谱线宽度为63.5 nm。研究结果表明，BGGS晶体是一种有前途的非线性光学材料，用于产生中红外光谱范围内的高能辐射。

{"title":"An optical parametric oscillator based on BaGa2GeS6 with energy exceeding 2 mJ at 6.45 μm","authors":"E.Yu. Erushin , S.E. Sere , M.V. Vostrikova , A.A. Boyko , G.S. Shevyrdyaeva , D.V. Badikov , A.A. Karapuzikov , N.Yu. Kostyukova","doi":"10.1016/j.infrared.2026.106393","DOIUrl":"10.1016/j.infrared.2026.106393","url":null,"abstract":"<div><div>A high-energy optical parametric oscillator (OPO) based on a BaGa<sub>2</sub>GeS<sub>6</sub> (BGGS) nonlinear crystal pumped by a home-built Q-switched Nd:YAG laser operating at 1064 nm with 15 ns pulse duration and 10 Hz repetition rate was demonstrated and characterized. The system generated idler radiation near 6.45 μm with a maximum pump-to-idler conversion efficiency of 2.23 % at a pump energy of 92 mJ, corresponding to an idler output energy of 2.06 mJ. Over an hour monitoring period, the output energy stability was 1.9 % RMS, and the average beam quality factor was M<sup>2</sup> was determined to be 33 at a pump energy of 85 mJ. The phase-matching characteristics were experimentally studied via angular tuning of the BGGS crystal, and refined Sellmeier coefficients for the ordinary and extraordinary refractive indices were obtained using a least-squares fit, reducing the error between theory and experiment to 0.1°. The idler spectral linewidth, estimated by convolution of the measured pump and signal spectra, was 63.5 nm. The findings suggest that the BGGS crystal represents a promising nonlinear optical material for the generation of high-energy radiation within the mid-infrared spectral range.</div></div>","PeriodicalId":13549,"journal":{"name":"Infrared Physics & Technology","volume":"154 ","pages":"Article 106393"},"PeriodicalIF":3.4,"publicationDate":"2026-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974743","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}

引用次数: 0