Optics & Laser Technology最新文献

{"title":"Feature enhanced non-line-of-sight imaging using graph model in latent space","authors":"Weihao Xu, Songmao Chen, Dingjie Wang, Yuyuan Tian, Ning Zhang, Wei Hao, Xiuqin Su","doi":"10.1016/j.optlastec.2024.111538","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111538","url":null,"abstract":"Non-line-of-sight (NLoS) imaging reveals hidden scene from indirect diffusion signals. However, it is still challenging to balance noise suppression, detail preservation, and reconstruction efficiency. In this work, a robust framework which is centered on feature extractor and enhancement is proposed. In the framework, the feature extractor exploits the graph model in latent space for efficient noise suppression and detail preservation, the enhancement collaboratively learns the feature and data statistics by considering the extractor to define regularization. The reconstruction results on the publicly accessible datasets show that the proposed framework outperforms the state-of-art methods considering both quality and efficiency.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of low-power pulsed laser-induced single/double arc hybrid heat source bottoming welding of medium-thick plate titanium alloy","authors":"Huanyu Yang, Zhigang Cheng, Xingkong Tao, Liming Liu","doi":"10.1016/j.optlastec.2024.111623","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111623","url":null,"abstract":"In order to study the heat source characteristics and discharge mechanism of low power pulse laser induced arc/double arc hybrid welding technology in the narrow gap backing welding process of titanium alloy medium-thick plate, laser-TIG (L-TIG) hybrid welding and laser-double TIG (L-DTIG) hybrid welding technology were used in this paper. Welding experiments were carried out under different blunt edge thicknesses. Two kinds of welding methods were used to compare the influence of the temperature field of the weld, the morphology of the coupled plasma and the energy distribution of the plasma, the coupling driving force and the force state of the plasma, and the influence of the microstructure and properties of the weld. The results show that the welding heat input of L-DTIG is significantly lower than that of L-TIG hybrid heat source, and there is a larger process interval in the backing welding of different blunt edge thicknesses. Under the action of pulsed laser, the L-DTIG hybrid heat source plasma has a larger central conductive area and electron density, which are 1.68 times and 1.42 times of the L-TIG hybrid heat source, respectively. Due to the small heat input of L-DTIG hybrid welding, the grain size is significantly reduced, so that the hardness of the weld zone and the heat affected zone is slightly higher than that of the L-TIG hybrid heat source, and the hardness distribution from the weld center to the base metal shows a downward trend. Due to the stronger induction and compression ability of the pulsed laser to the double TIG arc, the energy density of the L-DTIG hybrid heat source is more concentrated, which is beneficial to reduce the welding heat input and improve the welding efficiency and the overall performance of the welded joint.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep learning enabled design of terahertz high-Q metamaterials","authors":"Shan Yin, Haotian Zhong, Wei Huang, Wentao Zhang","doi":"10.1016/j.optlastec.2024.111684","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111684","url":null,"abstract":"Metamaterials open up a new way to manipulate electromagnetic waves and realize various functional devices. Metamaterials with high-quality factor (Q) resonance responses are widely employed in sensing, detection, and other applications. Traditional design of metamaterials involves laborious simulation-optimization and limits the efficiency. The high-Q metamaterials with abrupt spectral change are even harder to reverse design on-demand. In this paper, we propose novel solutions for designing terahertz high-Q metamaterials based on deep learning, including the inverse design of structural parameters and the forward prediction of spectral responses. For the inverse design, we introduce the big data Visual Attention Network (VAN) model with a large model capability, and take additional parameter tuning for the key sensitive parameters and predict them individually, which can efficiently reduce errors and achieve highly accurate inverse design of structural parameters according to the target high-Q resonance responses. For the forward prediction, we develop the Electromagnetic Response Transformer (ERT) model to establish the complex mapping relations between the highly sensitive structural parameters and the abrupt spectra, and realize precise prediction of the high-Q resonance in terahertz spectra from given structural parameters. Our ERT model can be 4000 times faster than the conventional full wave simulations in computation time. Both models exhibit outstanding performance, and the accuracy is improved one or two orders higher compared to the traditional machine learning methods. Our work provides new avenues for the deep learning enabled design of terahertz high-Q metamaterials, which holds potential applications in various fields, such as terahertz communication, sensing, imaging, and functional devices.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Single-shot 3D measurement via deep learning fringe projection profilometry with geometric constraints","authors":"Ze Li, Jianhua Wang, Suzhen Wang, Wen Zhang, Shuo Shan, Yanxi Yang","doi":"10.1016/j.optlastec.2024.111735","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111735","url":null,"abstract":"Single-shot three-dimensional (3D) measurement has always been the ultimate goal of fringe projection profilometry (FPP). Some studies have shown that deep learning outperforms traditional algorithm in analyzing single fringe pattern for complex scenarios. However, accurately phase unwrapping for a single wrapped phase map remains a significant challenge. In this paper, we propose a deep learning-based fringe projection profilometry. This method considers the geometric constraints of the measurement system. With the reference phase generated by the calibration parameters and appropriately designed intermediate variables based on physical models and prior knowledge, the proposed method is capable of recovering high-quality absolute phase from a single fringe pattern at the accuracy sufficiently high to rival traditional multi-frame algorithms. In addition, as far as FPP is concerned, the significance of the reference phase generated by the calibration parameters of the measurement system for deep learning-based single-frame phase unwrapping is experimentally demonstrated. Experiments on both static and dynamic scenarios show that the proposed method can achieves motion-artifact-free and high-resolution single-shot 3D measurements in various complex scenarios using only a single-frequency fringe projection.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient watt-level fluoride fiber laser beyond 3 μm enabled by direct diode pumping","authors":"Xiangyu Zhao, Hongyu Luo","doi":"10.1016/j.optlastec.2024.111715","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111715","url":null,"abstract":"Rare-earth-ion-doped fluoride fiber laser enabled by direct diode pumping provides a compact and robust platform for mid-infrared production, thereby serving a number of real-world applications. Nowadays, the power of such an architecture beyond 3 μm, however, has been clamped at < 1 W due to lack of readily available laser diode and/or efficient operation mechanism. In this work, we experimentally present efficient watt-level power output beyond 3 μm from an Er/Dy codoped fluoride fiber laser, clad-pumped by a cost-effective 974 nm diode, for the first time. In a free-running F-P scheme with an optimized output coupler reflectivity of 33 %, a maximum output power of 3.03 W at ∼3210 nm has been achieved with a slope efficiency of up to 19.1 % (with respect to the coupled pump), representing the first > 1 W diode-pumped rare-earth-ion-doped fiber laser beyond 3 µm with the highest efficiency. Then the numerical model, validated by our experimental data, has been built up, in which the previously ignored processes (i.e., ∼2.8 µm emission of Er and absorption of Dy) have been considered as an equivalent cross relaxation process, and confirmed probably to be the dominant role in determining efficient operation of this system. Using the model, the numerical optimization and performance prediction have been performed. Numerical comparison with the state-of-the-art Dy-doped fluoride fiber laser in this band based on tandem pumping approach indicates great potential of Er/Dy codoped system in high-power operation and its merits of compactness and high cost effectiveness as a promising alternative scheme.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent progress of laser processing technology in micro-LED display manufacturing: A review","authors":"Lingxiao Song, Xuechao Yong, Peilei Zhang, Shijie Song, Kefan Chen, Hua Yan, Tianzhu Sun, Qinghua Lu, Haichuan Shi, Yu Chen, Yuze Huang","doi":"10.1016/j.optlastec.2024.111710","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111710","url":null,"abstract":"Micro-LED undoubtedly stands out as a highly anticipated technology when it comes to the innovation of future display technologies. Micro-LED technology surpasses traditional display technologies regarding color representation, energy efficiency, and flexibility by individually assembling tiny light-emitting diodes on a substrate. Micro-LED technology, a further evolution of LED, is considered the most promising next-generation display technology due to its outstanding brightness, high contrast ratio, and extremely high pixel density. The application of laser technology in Micro-LED displays is increasingly becoming a focus of research and industry. As a highly integrated light source, lasers offer unique advantages in Micro-LED applications, including high-energy density processing, non-contact processing, precise microstructure processing and sculpting capability, efficient packaging, and improved device quality and reliability. These advantages provide a distinctive edge in achieving high-precision manufacturing and assembly of Micro-LED chips. Laser epitaxy substrate technology utilizes laser heating and material deposition to grow Micro-LED chips on a substrate. Laser etching technology achieves precise control of lasers to enable microstructure processing and sculpting of Micro-LED devices. Laser lift-off technology utilizes laser-induced decomposition of GaN to peel off the underlying material, allowing for the separation of Micro-LEDs. Laser-based massive transfer technology uses the energy of lasers to swiftly and accurately transfer Micro-LEDs from the substrate to the target substrate, enabling rapid device transfer. Lastly, laser repair technology is employed for the detection and repair of potential defects in Micro-LEDs, enhancing device quality and reliability. By utilizing lasers, we can expect to achieve higher production efficiency, more precise device manufacturing, and superior optoelectronic performance in the field of Micro-LED, thereby presenting broader prospects for future display technology and lighting applications. These laser technologies provide new solutions for Micro-LED devices’ high-precision and high-efficiency production.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Free-running dual-comb system based on environment-shared fiber lasers with passively thermal management","authors":"Qiuying Ma, Haoyang Yu, Hao Li, Kaiyang Ding, Xiaojun Liang, Xiaohao Wang, Qian Zhou, Kai Ni","doi":"10.1016/j.optlastec.2024.111586","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111586","url":null,"abstract":"Dual combs are widely recognized for their significant applications in precision measurement, due to their high spectral resolution, broad spectral range and high speed. However, the tight locking dual-comb system faces challenges in terms of complexity, cost, and power consumption, limiting their widespread field applications. We introduced a free-running dual-comb system based on environment-shared fiber lasers with passively thermal management. This thermal management system features a novel three-layer thermal shielding cavity, designed using a mathematical model based on an analogy with an RC filter circuit. This method allows for optimized design parameters, reducing both complexity and cost. To confirm its effectiveness, we validate the proposed method through both finite element analysis and experiments. Our all-fiber, free-running dual-comb system demonstrates excellent stability in the repetition frequency difference and the sub-comb radio frequency spectrum, providing a straightforward and viable solution for field-deployable applications.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Compact binocular holographic near-eye 3D display system based on a liquid crystal polarization grating","authors":"Fan-Chuan Lin, Qian Huang, Yi-Wei Zheng, Di Wang, Qiong-Hua Wang","doi":"10.1016/j.optlastec.2024.111725","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111725","url":null,"abstract":"Holographic technology is considered as one of the most ideal 3D display technologies and has significant potential in near-eye display. However, binocular holographic near-eye 3D display still faces challenges such as serious visual fatigue and complex system. Here, we propose a compact binocular holographic near-eye 3D display system based on a liquid crystal polarization grating (LCPG). Based on the LCPG, the reconstructed light can be deflected respectively to left and right viewing areas. The proposed system achieves binocular display with only one phase-only spatial light modulator used to load computer-generated hologram, which makes the binocular display system more compact. Simultaneously, the proposed system reduces mismatches in the images perceived by two eyes, thus achieving a better binocular display effect. Experimental results demonstrate the feasibility of the proposed binocular holographic near-eye 3D display system with dual viewing areas. Additionally, based on the time-division multiplexing method, dynamic binocular holographic near-eye display can be achieved. The proposed system has potential applications in holographic virtual reality and augmented reality display.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-Precision distributed fiber optic vibration positioning system with grating array","authors":"Yulin Wang, Yunfan Xu, Sen Zhu, Yanyan Liu, Weibin Feng, Xinxing Ma, Yuefeng Qi","doi":"10.1016/j.optlastec.2024.111721","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111721","url":null,"abstract":"The conventional distributed fiber optic positioning system (DFOPS) employing a single pulse working has a mutually constrained relationship between resolution and measurement distance, thereby imposing severe limitations on the advancement of DFOPS development. To solve this problem, we propose a strain and vibration event positioning system by employing correlated positioning techniques, pulse coding techniques, a broadband light source, and arrays of weakly reflective fiber gratings. To further improve the positioning accuracy of the system, the chip subdivision method and correlation prediction method are used to achieve centimeter-level localization accuracy in this study. In addition to correlation localization, we also propose a superposition signal decomposition model to achieve vibration event localization. Finally, to determine the most appropriate coding method for the system, a comparative analysis is performed to evaluate different coding methods in terms of coding gain, transmission time, and decoding complexity. We hope that the system and methods presented in this paper can serve as a valuable reference in the field of distributed fiber optic sensing with grating arrays for vibration detection.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The fiber surface plasmon resonance sensor based on TiO2 /Au-NPs sensitization","authors":"Hua-Long Du, Nuerguli Kari, Ben Li, Qi Wang","doi":"10.1016/j.optlastec.2024.111697","DOIUrl":"https://doi.org/10.1016/j.optlastec.2024.111697","url":null,"abstract":"The fiber Surface plasmon resonance (SPR) sensor based on titanium dioxide(TiO) and Au nanoparticles (Au-NPs) sensitization is offered as a practical means of increasing the sensitivity and figure of merit (FOM). Through finite element simulation and experimental testing, it is found that in TiO with high dielectric constant and high dielectric conductivity, the carrier movement is fast and consumption is low, which enhances the photocurrent signal and leads to charge redistribution, thus enhances the electric field; while the Au-NPs will stimulate the stronger Localized Surface plasmon resonance (LSPR) phenomenon, and both of them will undergo electric field resonance coupling. The sensitivity of the sensor is higher because its surface electric field is 3.67 times stronger than the conventional Au film sensor. When exposed to external conditions, the sensitivity can reach 9715 nm/RIU within the refractive index (RI) at 1.33213–1.34055, which is 4.69 times higher than a conventional Au film sensor. The FOM can reach 57.8 RIU, which is 2.05 times higher than the conventional Au film sensor. In addition, TiO and Au-NPs on the surface of the sensor are less prone to collapse, and the stability test results show that the relative standard deviation (RSD) is 0.5929 %, which exhibits good reliability and stability. The structure of the sensor is very simple, relatively easy to fabricate, and has good applicability in the field of biochemical testing.","PeriodicalId":19597,"journal":{"name":"Optics & Laser Technology","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}