Pub Date : 2024-11-30DOI: 10.1016/j.optlaseng.2024.108735
Zehui Gu, Yuyang He, Jinghu Ji, Yifan Wei, Yonghong Fu
Owing to the anisotropic and heterogeneous properties of carbon fiber reinforced plastics (CFRP), laser drilling processes often lead to substantial heat-affected zone (HAZ) and taper formation. The introduction of a medium to facilitate heat conduction during laser processing has emerged as an efficacious strategy to mitigate these challenges. In this study, a sacrificial layer was added to the back of the CFRP plate to reduce the taper and HAZ produced by laser drilling. The effects of laser power, scanning speed, and pulse frequency on hole surface morphology and HAZ evolution were investigated. By adding a sacrificial layer, the taper was reduced by 4.6 % to 31.4 %, the exit roundness im-proved by 1.11 % to 2.56 %, and the HAZ on the exit surface decreased by 47.6 % to 61.9 %. The sacrificial layer had minimal impact on the entrance diameter and HAZ. This study provides a reference for improving the quality of laser drilling in CFRP plates.
{"title":"Reducing the taper and heat-affected zone in nanosecond laser drilling of CFRP plate using backside sacrificial layer","authors":"Zehui Gu, Yuyang He, Jinghu Ji, Yifan Wei, Yonghong Fu","doi":"10.1016/j.optlaseng.2024.108735","DOIUrl":"10.1016/j.optlaseng.2024.108735","url":null,"abstract":"<div><div>Owing to the anisotropic and heterogeneous properties of carbon fiber reinforced plastics (CFRP), laser drilling processes often lead to substantial heat-affected zone (HAZ) and taper formation. The introduction of a medium to facilitate heat conduction during laser processing has emerged as an efficacious strategy to mitigate these challenges. In this study, a sacrificial layer was added to the back of the CFRP plate to reduce the taper and HAZ produced by laser drilling. The effects of laser power, scanning speed, and pulse frequency on hole surface morphology and HAZ evolution were investigated. By adding a sacrificial layer, the taper was reduced by 4.6 % to 31.4 %, the exit roundness im-proved by 1.11 % to 2.56 %, and the HAZ on the exit surface decreased by 47.6 % to 61.9 %. The sacrificial layer had minimal impact on the entrance diameter and HAZ. This study provides a reference for improving the quality of laser drilling in CFRP plates.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"185 ","pages":"Article 108735"},"PeriodicalIF":3.5,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142757624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-30DOI: 10.1016/j.optlaseng.2024.108715
Yiyang Zhang , Zhewen Ding , Yan Shi , Jun Chen , Chunlian Zhan , Chunliu Zhao
Due to the ability to flexibly transmit optical signals and high spatial resolution, multimode fibers (MMFs) show great potential in micrometer-scale imaging, which can be used to observe biological organisms and living cells. To minimize damage to the observed subject, milliwatt to microwatt level illumination should be used for imaging, but lower optical power results in a lower signal-to-noise ratio of the imaged signal, and consequently the poorer imaging quality. In this paper, the effects of environmental and device noise on the imaging performance at low-power input are discussed through the simulation, and a low-power scanning imaging method based on the MMF and non-local mean (NLM) filtering is proposed for the first time. To validate the effectiveness of the proposed method, a low-power scanning imaging system based on MMF was built, and the effects of Gaussian filtering and NLM filtering on imaging results were compared. Experimental results show that NLM filtering is five times more effective than Gaussian filtering in improving the imaging resolution by about 12%. This work holds promise for providing new approaches and methods for low-power endoscopic imaging and in vivo cell imaging in biological organisms.
{"title":"Low-power scanning imaging based on multimode fiber and non-local mean filtering","authors":"Yiyang Zhang , Zhewen Ding , Yan Shi , Jun Chen , Chunlian Zhan , Chunliu Zhao","doi":"10.1016/j.optlaseng.2024.108715","DOIUrl":"10.1016/j.optlaseng.2024.108715","url":null,"abstract":"<div><div>Due to the ability to flexibly transmit optical signals and high spatial resolution, multimode fibers (MMFs) show great potential in micrometer-scale imaging, which can be used to observe biological organisms and living cells. To minimize damage to the observed subject, milliwatt to microwatt level illumination should be used for imaging, but lower optical power results in a lower signal-to-noise ratio of the imaged signal, and consequently the poorer imaging quality. In this paper, the effects of environmental and device noise on the imaging performance at low-power input are discussed through the simulation, and a low-power scanning imaging method based on the MMF and non-local mean (NLM) filtering is proposed for the first time. To validate the effectiveness of the proposed method, a low-power scanning imaging system based on MMF was built, and the effects of Gaussian filtering and NLM filtering on imaging results were compared. Experimental results show that NLM filtering is five times more effective than Gaussian filtering in improving the imaging resolution by about 12%. This work holds promise for providing new approaches and methods for low-power endoscopic imaging and in vivo cell imaging in biological organisms.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"185 ","pages":"Article 108715"},"PeriodicalIF":3.5,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-30DOI: 10.1016/j.optlaseng.2024.108722
Bohan Liu , Shaojie Men , Qiuyuan Yu , Dewei Li , Zhongjun Ding , Zhaojun Liu
There is an increasing demand for advanced imaging systems in marine exploration capable of performing high-resolution spectral analysis of targets in deep-sea environments. Traditional push-broom underwater hyperspectral imaging systems obtain hyperspectral images by relying on platform movement, which limits their applicability in complex underwater conditions. To mitigate this issue, we present a novel internal scanning underwater hyperspectral imaging system. In this system, a two-stage rotating mirror mechanism is designed, achieving a maximum 36° internal scanning field of view while maintaining characteristics of direct-view, compact and simple. We analyze and correct the geometric distortions of the hyperspectral image caused by the internal scan. Calibrations and experiments show that the system operates within a spectral range of 400–1000 nm, achieving a spectral resolution better than 3 nm, and a maximum working depth of 6000 m.
{"title":"Internal scanning hyperspectral imaging system for deep sea target detection","authors":"Bohan Liu , Shaojie Men , Qiuyuan Yu , Dewei Li , Zhongjun Ding , Zhaojun Liu","doi":"10.1016/j.optlaseng.2024.108722","DOIUrl":"10.1016/j.optlaseng.2024.108722","url":null,"abstract":"<div><div>There is an increasing demand for advanced imaging systems in marine exploration capable of performing high-resolution spectral analysis of targets in deep-sea environments. Traditional push-broom underwater hyperspectral imaging systems obtain hyperspectral images by relying on platform movement, which limits their applicability in complex underwater conditions. To mitigate this issue, we present a novel internal scanning underwater hyperspectral imaging system. In this system, a two-stage rotating mirror mechanism is designed, achieving a maximum 36° internal scanning field of view while maintaining characteristics of direct-view, compact and simple. We analyze and correct the geometric distortions of the hyperspectral image caused by the internal scan. Calibrations and experiments show that the system operates within a spectral range of 400–1000 nm, achieving a spectral resolution better than 3 nm, and a maximum working depth of 6000 m.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"185 ","pages":"Article 108722"},"PeriodicalIF":3.5,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-29DOI: 10.1016/j.optlaseng.2024.108716
Yongcui Mi , Fredrik Sikström , Luigi Angelastri , Pasquale Guglielmi , Gianfranco Palumbo , Antonio Ancona
This study explores the uncharted territory of beam shaping through a novel deformable mirror system in directed energy deposition laser wire, an emerging area in Additive Manufacturing. While beam shaping has shown substantial benefits in laser processes like welding and powder bed fusion, its potential in this specific domain remains unexploited. The research investigates the influence of three near-elliptical Gaussian beam shapes on melt pool and bead geometries during deposition with stainless-steel wire. The study reveals three distinct processing modes achievable at the same total power through beam shaping, with significant modifications observed in melt pool and bead structures. Reduced bead geometry variation and enhanced process stability were achieved with the beam shape with major axis along the wire feeding direction, and with highest average power density and intermediate peak power density. The findings underscore the potential of beam shaping to enhance robustness and increase energy utilization and productivity in this process.
{"title":"Improving laser directed energy deposition with wire feed-stock through beam shaping with a deformable mirror","authors":"Yongcui Mi , Fredrik Sikström , Luigi Angelastri , Pasquale Guglielmi , Gianfranco Palumbo , Antonio Ancona","doi":"10.1016/j.optlaseng.2024.108716","DOIUrl":"10.1016/j.optlaseng.2024.108716","url":null,"abstract":"<div><div>This study explores the uncharted territory of beam shaping through a novel deformable mirror system in directed energy deposition laser wire, an emerging area in Additive Manufacturing. While beam shaping has shown substantial benefits in laser processes like welding and powder bed fusion, its potential in this specific domain remains unexploited. The research investigates the influence of three near-elliptical Gaussian beam shapes on melt pool and bead geometries during deposition with stainless-steel wire. The study reveals three distinct processing modes achievable at the same total power through beam shaping, with significant modifications observed in melt pool and bead structures. Reduced bead geometry variation and enhanced process stability were achieved with the beam shape with major axis along the wire feeding direction, and with highest average power density and intermediate peak power density. The findings underscore the potential of beam shaping to enhance robustness and increase energy utilization and productivity in this process.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"185 ","pages":"Article 108716"},"PeriodicalIF":3.5,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The ill-posed nature of the tomographic inverse problem for soot volume fraction reconstruction often creates artifacts and provides lower reconstruction accuracy, particularly when viewing angles are limited. In this study, a volumetric masked-based 3-D Tikhonov regularization method is proposed to reconstruct soot volume fraction in a purely absorbing flame. The 3-D Tikhonov regularization method addresses the ill-posedness by penalizing unrealistic variations in the soot volume fraction, thus enhancing the robustness of the reconstruction. Additionally, volumetric masking derived from light field ray-tracing refines the reconstruction by accurately defining the flame's boundaries and improving the soot volume fraction inversion accuracy. Numerical simulations were conducted on a bimodal asymmetric flame to analyze the effects of varying viewing angles and volumetric masking strategies. Experimental studies were also performed to reconstruct soot volume fraction under different combustion operating conditions. Both numerical simulations and experimental studies demonstrate that the proposed method not only works on a limited number of viewing angles but also mitigates the reconstruction artifacts and decreases the computational costs.
{"title":"Volumetric reconstruction of soot volume fraction through 3-D masked Tikhonov regularization","authors":"Tianxiang Ling , Md. Moinul Hossain , Guoqing Chen , Qi Qi , Biao Zhang , Chuanlong Xu","doi":"10.1016/j.optlaseng.2024.108720","DOIUrl":"10.1016/j.optlaseng.2024.108720","url":null,"abstract":"<div><div>The ill-posed nature of the tomographic inverse problem for soot volume fraction reconstruction often creates artifacts and provides lower reconstruction accuracy, particularly when viewing angles are limited. In this study, a volumetric masked-based 3-D Tikhonov regularization method is proposed to reconstruct soot volume fraction in a purely absorbing flame. The 3-D Tikhonov regularization method addresses the ill-posedness by penalizing unrealistic variations in the soot volume fraction, thus enhancing the robustness of the reconstruction. Additionally, volumetric masking derived from light field ray-tracing refines the reconstruction by accurately defining the flame's boundaries and improving the soot volume fraction inversion accuracy. Numerical simulations were conducted on a bimodal asymmetric flame to analyze the effects of varying viewing angles and volumetric masking strategies. Experimental studies were also performed to reconstruct soot volume fraction under different combustion operating conditions. Both numerical simulations and experimental studies demonstrate that the proposed method not only works on a limited number of viewing angles but also mitigates the reconstruction artifacts and decreases the computational costs.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"185 ","pages":"Article 108720"},"PeriodicalIF":3.5,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-29DOI: 10.1016/j.optlaseng.2024.108724
Victor Marin-Lizarraga , Raúl Rodríguez-García , Jose L Garcia-Cordero , Daniel May-Arrioja , Clelia De-la-Peña , Luis David Patiño-López
Lensless imaging fluorescence applications are limited by the unavoidable trade-off between the object-sensor distance and the excitation light attenuation at the detection plane. Indeed, a shorter object-sensor distance reduces the spreading of fluorescent signals but at the cost of losing excitation light attenuation provided by filter thickness. Accordingly, the combination of four synergistic pathways to attain further attenuation of excitation light is proposed: the optimization of total internal reflection by microfluidic chip geometry modification, cross-polarization extinction, interchangeable absorption longpass filters, and the CMOS sensor built-in bandpass Bayer filters. The advantages of such a combined setup are demonstrated with a microfluidic application, as we managed to keep the object-sensor distance as short as 600 µm and still distinguish the fluorescence of individual droplets, flowing as close as 650 µm to each other, while attenuating excitation light to an OD 5.9 level. This approach also allowed simultaneous fluorescence and bright-field observation of on-chip droplet fluorescence during flow at a rate of 30 fps. The enhanced capabilities in our scheme pave the way to further lensless fluorescence applications requiring parallelism, lower detection thresholds, and real-time acquisition, such as fluorescence biosensing.
{"title":"Simultaneous bright-field and fluorescence lensless imaging with high excitation light extinction for microfluidics applications","authors":"Victor Marin-Lizarraga , Raúl Rodríguez-García , Jose L Garcia-Cordero , Daniel May-Arrioja , Clelia De-la-Peña , Luis David Patiño-López","doi":"10.1016/j.optlaseng.2024.108724","DOIUrl":"10.1016/j.optlaseng.2024.108724","url":null,"abstract":"<div><div>Lensless imaging fluorescence applications are limited by the unavoidable trade-off between the object-sensor distance and the excitation light attenuation at the detection plane. Indeed, a shorter object-sensor distance reduces the spreading of fluorescent signals but at the cost of losing excitation light attenuation provided by filter thickness. Accordingly, the combination of four synergistic pathways to attain further attenuation of excitation light is proposed: the optimization of total internal reflection by microfluidic chip geometry modification, cross-polarization extinction, interchangeable absorption longpass filters, and the CMOS sensor built-in bandpass Bayer filters. The advantages of such a combined setup are demonstrated with a microfluidic application, as we managed to keep the object-sensor distance as short as 600 µm and still distinguish the fluorescence of individual droplets, flowing as close as 650 µm to each other, while attenuating excitation light to an OD 5.9 level. This approach also allowed simultaneous fluorescence and bright-field observation of on-chip droplet fluorescence during flow at a rate of 30 fps. The enhanced capabilities in our scheme pave the way to further lensless fluorescence applications requiring parallelism, lower detection thresholds, and real-time acquisition, such as fluorescence biosensing.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"185 ","pages":"Article 108724"},"PeriodicalIF":3.5,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-28DOI: 10.1016/j.optlaseng.2024.108696
Fengyi Zhang , Zhisong Li , Xin Tang
To address the challenge of obtaining high-quality interferometric images in the presence of environmental disturbances, this paper proposes a method for interferometric image reorganization and screening based on the phase-shift convergence criterion. The method begins with the acquisition of multiple sets of interferometric images, which are subsequently classified and reorganized according to the amount of phase shift. A mean absolute deviation metric is then employed to systematically screen the classified images, allowing for the selection of a subset that exhibits accurate phase shifts. Finally, the screened and combined interferometric images are evaluated for phase shift centralization through the calculation of the coefficient of variation, ensuring that the screened images conform to the expected criteria. The experimental results indicate that the average coefficient of variation of the screened interferometric images obtained using the proposed method is significantly reduced by 0.1236, 0.0968, and 0.1042 when compared to the nine sets of directly acquired interferometric images subjected to high-frequency vibration, high-amplitude vibration, and transverse distortion vibration, respectively. These data demonstrate that the proposed method can effectively adapt to various vibration environments while screening interferometric images of higher quality. Consequently, this method offers a novel approach to enhancing the vibration resistance of interferometers.
{"title":"Interferometric image reorganization and screening method based on phase-shift convergence criterion","authors":"Fengyi Zhang , Zhisong Li , Xin Tang","doi":"10.1016/j.optlaseng.2024.108696","DOIUrl":"10.1016/j.optlaseng.2024.108696","url":null,"abstract":"<div><div>To address the challenge of obtaining high-quality interferometric images in the presence of environmental disturbances, this paper proposes a method for interferometric image reorganization and screening based on the phase-shift convergence criterion. The method begins with the acquisition of multiple sets of interferometric images, which are subsequently classified and reorganized according to the amount of phase shift. A mean absolute deviation metric is then employed to systematically screen the classified images, allowing for the selection of a subset that exhibits accurate phase shifts. Finally, the screened and combined interferometric images are evaluated for phase shift centralization through the calculation of the coefficient of variation, ensuring that the screened images conform to the expected criteria. The experimental results indicate that the average coefficient of variation of the screened interferometric images obtained using the proposed method is significantly reduced by 0.1236, 0.0968, and 0.1042 when compared to the nine sets of directly acquired interferometric images subjected to high-frequency vibration, high-amplitude vibration, and transverse distortion vibration, respectively. These data demonstrate that the proposed method can effectively adapt to various vibration environments while screening interferometric images of higher quality. Consequently, this method offers a novel approach to enhancing the vibration resistance of interferometers.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"185 ","pages":"Article 108696"},"PeriodicalIF":3.5,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-28DOI: 10.1016/j.optlaseng.2024.108721
Yuxuan Zhao , Lei Zeng , Zhiming Lin , Qiwen Jin , Yingchun Wu , Chenghang Zheng , Zhibin Wang , Yongxin Zhang , Xuecheng Wu
Dual-wavelength digital holographic microscopy is a method to acquire surface topography of high-depth samples, offering a broader depth range compared to single-wavelength technique. When applying to high aspect ratio structures, however, optical aberrations are difficult to remove, resulting in phase restoration distortions. To address this limitation, we developed a layered phase restoration method for DW-DHM. This approach restores the phase by decomposing the step structure into layers and applying a targeted de-aberration process at each layer, followed by precise dual-wavelength phase unwrapping through linear programming algorithm (LPA). Simulations and experimental results show that, while preserving the noise robustness of LPA, the proposed method provides significantly enhanced resistance to various aberrations. For topographic measurements of complex micro-nano scale step structures, this approach effectively mitigates the issue in LPA where the phase restoration affected by hard-to-eliminate aberrations, demonstrating its potential for advanced applications in micro-nano device measurement.
{"title":"Layered phase restoration method for dual-wavelength digital holographic microscopy based on linear programming","authors":"Yuxuan Zhao , Lei Zeng , Zhiming Lin , Qiwen Jin , Yingchun Wu , Chenghang Zheng , Zhibin Wang , Yongxin Zhang , Xuecheng Wu","doi":"10.1016/j.optlaseng.2024.108721","DOIUrl":"10.1016/j.optlaseng.2024.108721","url":null,"abstract":"<div><div>Dual-wavelength digital holographic microscopy is a method to acquire surface topography of high-depth samples, offering a broader depth range compared to single-wavelength technique. When applying to high aspect ratio structures, however, optical aberrations are difficult to remove, resulting in phase restoration distortions. To address this limitation, we developed a layered phase restoration method for DW-DHM. This approach restores the phase by decomposing the step structure into layers and applying a targeted de-aberration process at each layer, followed by precise dual-wavelength phase unwrapping through linear programming algorithm (LPA). Simulations and experimental results show that, while preserving the noise robustness of LPA, the proposed method provides significantly enhanced resistance to various aberrations. For topographic measurements of complex micro-nano scale step structures, this approach effectively mitigates the issue in LPA where the phase restoration affected by hard-to-eliminate aberrations, demonstrating its potential for advanced applications in micro-nano device measurement.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"185 ","pages":"Article 108721"},"PeriodicalIF":3.5,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-27DOI: 10.1016/j.optlaseng.2024.108712
Jin Duan , Meiling Gao , Guangyu Zhao , Jianhua Liu , Zhiyu Zhang , Xuedong He
In view of the challenges posed by low light environments, we propose a method for enhancing color polarization images, called DStokes-CGCP. This method employs a dual-branch architecture to effectively leverage the distinct characteristics of different components of the Stokes vector, thereby enhancing the utilization of polarization information. Firstly, the chroma spectrum branch (f(CS)) extracts features in the spatial and frequency domains based on the low-frequency information of S0, effectively fusing the information between feature maps of different dimensions, thereby compensating for the loss of spatial domain information and improving image clarity. Secondly, the global contour awareness branch (f(GCA)) captures the details and edge information of the image through edge and global feature extraction for the high-frequency components of S1 and S2, and further enhances the clarity and texture details of S1 and S2. Additionally, this study introduces a new dataset, named RCPI. Experimental results show that DStokes-CGCP performs well in improving the quality of low-light images and enhancing the naturalness of the effect.
{"title":"DStokes-CGCP: A low-light color polarization image enhancement method combining chroma spectrum and global contour awareness","authors":"Jin Duan , Meiling Gao , Guangyu Zhao , Jianhua Liu , Zhiyu Zhang , Xuedong He","doi":"10.1016/j.optlaseng.2024.108712","DOIUrl":"10.1016/j.optlaseng.2024.108712","url":null,"abstract":"<div><div>In view of the challenges posed by low light environments, we propose a method for enhancing color polarization images, called DStokes-CGCP. This method employs a dual-branch architecture to effectively leverage the distinct characteristics of different components of the Stokes vector, thereby enhancing the utilization of polarization information. Firstly, the chroma spectrum branch (<em>f<sub>(CS)</sub></em>) extracts features in the spatial and frequency domains based on the low-frequency information of <em>S</em><sub>0</sub>, effectively fusing the information between feature maps of different dimensions, thereby compensating for the loss of spatial domain information and improving image clarity. Secondly, the global contour awareness branch (<em>f</em><sub>(</sub><em><sub>GCA</sub></em><sub>)</sub>) captures the details and edge information of the image through edge and global feature extraction for the high-frequency components of <em>S</em><sub>1</sub> and <em>S</em><sub>2</sub>, and further enhances the clarity and texture details of <em>S</em><sub>1</sub> and <em>S</em><sub>2</sub>. Additionally, this study introduces a new dataset, named RCPI. Experimental results show that DStokes-CGCP performs well in improving the quality of low-light images and enhancing the naturalness of the effect.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"185 ","pages":"Article 108712"},"PeriodicalIF":3.5,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-26DOI: 10.1016/j.optlaseng.2024.108718
Zihan Lin, Shuhai Jia, YuanCheng Xu, Bo Wen, Huajian Zhang, Longning Wang, Mengyu Han
Digital holographic microscopy (DHM) is a quantitative phase measurement technique with full-field, contactless, and fast. The technique provides accurate micro-surface morphology of samples. These steps are essential for accurate phase reconstruction, such as holographic focusing, numerical diffraction, phase unwrapping and distortion compensation. Performing these processes manually is time-consuming and is not conducive to the general application of the technology. In order to improve the detection efficiency, this paper proposes a deep learning model that can achieve fast identification of DHM phase distortion and automatic phase distortion compensation reconstruction. The model can be preprocessed for holographic phase to accurately identify the type of phase distortion present in the phase. And adaptively adjust the network weight parameters for phase distortion compensation reconstruction. The experimental results show that the method proposed in this paper achieves fast and accurate identification of multiple phase distortions. The model has high accuracy and strong generalization ability. The reconstructed holographic phase map has PSNR of 35.2743dB and RMSE as low as 10-2 level in the face of complex mixed aberrations. The identification and reconstruction processes took 0.005s and 0.058s, both in milliseconds, respectively. The evaluation indexes SSIM, FSIM and NC can reach above 0.99. It is shown that the method in this paper is not only capable of reconstructing holograms, but also able to effectively retain the detailed features of the original image.
{"title":"Fast phase distortion identification and automatic distortion compensated reconstruction for digital holographic microscopy using deep learning","authors":"Zihan Lin, Shuhai Jia, YuanCheng Xu, Bo Wen, Huajian Zhang, Longning Wang, Mengyu Han","doi":"10.1016/j.optlaseng.2024.108718","DOIUrl":"10.1016/j.optlaseng.2024.108718","url":null,"abstract":"<div><div>Digital holographic microscopy (DHM) is a quantitative phase measurement technique with full-field, contactless, and fast. The technique provides accurate micro-surface morphology of samples. These steps are essential for accurate phase reconstruction, such as holographic focusing, numerical diffraction, phase unwrapping and distortion compensation. Performing these processes manually is time-consuming and is not conducive to the general application of the technology. In order to improve the detection efficiency, this paper proposes a deep learning model that can achieve fast identification of DHM phase distortion and automatic phase distortion compensation reconstruction. The model can be preprocessed for holographic phase to accurately identify the type of phase distortion present in the phase. And adaptively adjust the network weight parameters for phase distortion compensation reconstruction. The experimental results show that the method proposed in this paper achieves fast and accurate identification of multiple phase distortions. The model has high accuracy and strong generalization ability. The reconstructed holographic phase map has PSNR of 35.2743dB and RMSE as low as 10<sup>-2</sup> level in the face of complex mixed aberrations. The identification and reconstruction processes took 0.005s and 0.058s, both in milliseconds, respectively. The evaluation indexes SSIM, FSIM and NC can reach above 0.99. It is shown that the method in this paper is not only capable of reconstructing holograms, but also able to effectively retain the detailed features of the original image.</div></div>","PeriodicalId":49719,"journal":{"name":"Optics and Lasers in Engineering","volume":"185 ","pages":"Article 108718"},"PeriodicalIF":3.5,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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