Pub Date : 2025-01-20DOI: 10.1016/j.optlastec.2025.112435
Yongbo Yao, Haixia Wang, Haohao Sun, Zilan Pan
Optical interferometric techniques have been proven to be attractive in both research and engineering fields for non-contact, high measurement accuracy and full-field detection. Fringe patterns are the recorded results by these techniques and usually require denoising to improve the accuracy of information retrieval. Most researches on fringe pattern denoising do not take into account both uneven illumination and speckle noise. However, the uneven illumination of fringe pattern can lead to more prominent noise in certain areas, affecting the performance of denoising methods. We propose a fringe pattern denoising method called UI-MSDE-diffusion, which consists of two steps. In the first step, the fringe pattern under different lighting conditions is transferred to uniform illumination through a unified illumination network, denoted as UINet. In the second step, speckle noise in the fringe pattern is filtered out by combining the mean-reverting stochastic differential equation and the diffusion model, denoted as MSDE-diffusion. Experiments on simulated and experimental fringe patterns are performed to demonstrate the effectiveness of the proposed UI-MSDE-diffusion method.
{"title":"UI-MSDE-diffusion: Fringe pattern noise elimination based on diffusion model","authors":"Yongbo Yao, Haixia Wang, Haohao Sun, Zilan Pan","doi":"10.1016/j.optlastec.2025.112435","DOIUrl":"10.1016/j.optlastec.2025.112435","url":null,"abstract":"<div><div>Optical interferometric techniques have been proven to be attractive in both research and engineering fields for non-contact, high measurement accuracy and full-field detection. Fringe patterns are the recorded results by these techniques and usually require denoising to improve the accuracy of information retrieval. Most researches on fringe pattern denoising do not take into account both uneven illumination and speckle noise. However, the uneven illumination of fringe pattern can lead to more prominent noise in certain areas, affecting the performance of denoising methods. We propose a fringe pattern denoising method called UI-MSDE-diffusion, which consists of two steps. In the first step, the fringe pattern under different lighting conditions is transferred to uniform illumination through a unified illumination network, denoted as UINet. In the second step, speckle noise in the fringe pattern is filtered out by combining the mean-reverting stochastic differential equation and the diffusion model, denoted as MSDE-diffusion. Experiments on simulated and experimental fringe patterns are performed to demonstrate the effectiveness of the proposed UI-MSDE-diffusion method.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"184 ","pages":"Article 112435"},"PeriodicalIF":4.6,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143150274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-20DOI: 10.1016/j.optlastec.2025.112483
Wenqing Sun , Huihui Wang , Xiaosong Li , Yuanfei Hui , Feng Zhang , Meng Wang , Baolu Guan
Circularly polarized lasers have gained attention for their advantages in 3D laser displays and spatial laser carrier communication. However, generating chiral light are both bulky and lousy, and requires complex manufacturing technology. Therefore, there is a critical need for ultracompact chiral lasers with simple operation, to develop highly integrated and cost-effective optical systems. In this work, circularly polarized VCSEL array was fabricated using the circular dichroism of cholesteric liquid crystal film, coupled with on-chip integration. This approach has improved the uniformity of beam quality and enabled temperature-controlled polarization characteristics. We achieved a laser with a high degree of left-circular polarization and an extinction ratio of up to 22. Furthermore, our work extends to arrays comprising 233 photons and larger, paving the way for applications in compact, high-power circularly polarized laser sources.
{"title":"High uniformity temperature tunable ultra-compact vertical-cavity surface emitting circularly polarized laser array","authors":"Wenqing Sun , Huihui Wang , Xiaosong Li , Yuanfei Hui , Feng Zhang , Meng Wang , Baolu Guan","doi":"10.1016/j.optlastec.2025.112483","DOIUrl":"10.1016/j.optlastec.2025.112483","url":null,"abstract":"<div><div>Circularly polarized lasers have gained attention for their advantages in 3D laser displays and spatial laser carrier communication. However, generating chiral light are both bulky and lousy, and requires complex manufacturing technology. Therefore, there is a critical need for ultracompact chiral lasers with simple operation, to develop highly integrated and cost-effective optical systems. In this work, circularly polarized VCSEL array was fabricated using the circular dichroism of cholesteric liquid crystal film, coupled with on-chip integration. This approach has improved the uniformity of beam quality and enabled temperature-controlled polarization characteristics. We achieved a laser with a high degree of left-circular polarization <span><math><mrow><mfenced><mrow><mrow><msub><mtext>S</mtext><mn>3</mn></msub><mo>≈</mo><mo>-</mo><mn>0.99</mn><mo>,</mo><mrow><mtext>the maxima of</mtext><mspace></mspace></mrow><mrow><mfenced><mrow><msub><mtext>S</mtext><mn>3</mn></msub></mrow></mfenced></mrow><mrow><mspace></mspace><mtext>is 1</mtext></mrow></mrow></mrow></mfenced></mrow></math></span> and an extinction ratio of up to 22. Furthermore, our work extends to arrays comprising 233 photons and larger, paving the way for applications in compact, high-power circularly polarized laser sources.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"184 ","pages":"Article 112483"},"PeriodicalIF":4.6,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143150275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-19DOI: 10.1016/j.optlastec.2025.112493
Zhiwei Guan , Jing Yang , Jianjun Ren , Chuangxin Xie , Lvye Nong , Liyu Huang , Tianyimei Zuo , Ze Dong , Chaofeng Wang , Dianyuan Fan
Cylindrical vector beam (CVB) provides an attractive prospect in enhancing the capacity density of optical communication via mode multiplexing. However, the mode coupling in few-mode fiber will disturb the mode power distribution of CVBs randomly, which causes crosstalk and signal fading, severely degrading the system performance and even interrupting communication. Here, we propose a diversity gain strategy to mitigate the crosstalk and signal fading in CVB multiplexing communication. By performing multi-input multi-output equalization on the receiving signals and estimating the channel matrix by solving the optimal mode channel weights, the diversity gain is performed to equalize the crosstalk-induced noise components and random signal errors, and the crosstalk and signal fading are mitigated. As a proof of concept, we experimentally demonstrate a multi-dimensional multiplexing communication (320 channels combined by 4 CVBs and 80 wavelengths), and 7.5 Tbit/s QPSK-OFDM signals are transmitted in 5 km few-mode fiber. We show that after diversity gain, the bit-error-rate is improved by about 2–3 orders of magnitude, and the communication outage of 60 % is completely suppressed. These validate that the diversity gain effectively eliminates crosstalk and signal fading caused by mode coupling in CVB multiplexing transmission over few-mode fiber, which significantly enhances communication capacity while greatly improving the stability and reliability of the communication system. It provides an effective solution for future high-capacity and long-distance optical communication.
{"title":"Diversity gain in cylindrical vector beam multiplexing","authors":"Zhiwei Guan , Jing Yang , Jianjun Ren , Chuangxin Xie , Lvye Nong , Liyu Huang , Tianyimei Zuo , Ze Dong , Chaofeng Wang , Dianyuan Fan","doi":"10.1016/j.optlastec.2025.112493","DOIUrl":"10.1016/j.optlastec.2025.112493","url":null,"abstract":"<div><div>Cylindrical vector beam (CVB) provides an attractive prospect in enhancing the capacity density of optical communication via mode multiplexing. However, the mode coupling in few-mode fiber will disturb the mode power distribution of CVBs randomly, which causes crosstalk and signal fading, severely degrading the system performance and even interrupting communication. Here, we propose a diversity gain strategy to mitigate the crosstalk and signal fading in CVB multiplexing communication. By performing multi-input multi-output equalization on the receiving signals and estimating the channel matrix by solving the optimal mode channel weights, the diversity gain is performed to equalize the crosstalk-induced noise components and random signal errors, and the crosstalk and signal fading are mitigated. As a proof of concept, we experimentally demonstrate a multi-dimensional multiplexing communication (320 channels combined by 4 CVBs and 80 wavelengths), and 7.5 Tbit/s QPSK-OFDM signals are transmitted in 5 km few-mode fiber. We show that after diversity gain, the bit-error-rate is improved by about 2–3 orders of magnitude, and the communication outage of 60 % is completely suppressed. These validate that the diversity gain effectively eliminates crosstalk and signal fading caused by mode coupling in CVB multiplexing transmission over few-mode fiber, which significantly enhances communication capacity while greatly improving the stability and reliability of the communication system. It provides an effective solution for future high-capacity and long-distance optical communication.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"184 ","pages":"Article 112493"},"PeriodicalIF":4.6,"publicationDate":"2025-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143150273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-18DOI: 10.1016/j.optlastec.2025.112487
Yanfei Hu, ZiYi Hao, Xinbing Wang, Duluo Zuo
The paper employs various optical analysis methods to study the stability of continuous fiber laser sustained Xe plasma under different laser power and focusing systems. High-speed cameras were used to capture plasma images from two directions, allowing a quantitative description of the fluctuation amplitudes of the plasma centroid and diameter. Standard deviation analysis revealed that a tightly focused system and increased laser power are more favorable for improving plasma stability. High-speed photodiodes and piezoelectric film sensors were simultaneously employed to monitor changes in plasma luminous intensity and internal gas pressure, showing that the fluctuation signals of both were consistent in shape and variation. The Schlieren method revealed the presence of periodically rising thermal bubbles around the plasma. Fourier transform spectra identified a 30 Hz low frequency and several hundred Hz high frequencies in the fluctuations of the plasma centroid, diameter, and brightness, while the piezoelectric signal contained only the low frequency. Further analysis concluded that the high frequencies originate from laser power fluctuations, while the low frequencies are caused by gas convection. As the laser power increases, the frequency of the low frequency gradually decreases to a gentle level.
{"title":"Stability analysis of continuous fiber laser sustained Xe plasma","authors":"Yanfei Hu, ZiYi Hao, Xinbing Wang, Duluo Zuo","doi":"10.1016/j.optlastec.2025.112487","DOIUrl":"10.1016/j.optlastec.2025.112487","url":null,"abstract":"<div><div>The paper employs various optical analysis methods to study the stability of continuous fiber laser sustained Xe plasma under different laser power and focusing systems. High-speed cameras were used to capture plasma images from two directions, allowing a quantitative description of the fluctuation amplitudes of the plasma centroid and diameter. Standard deviation analysis revealed that a tightly focused system and increased laser power are more favorable for improving plasma stability. High-speed photodiodes and piezoelectric film sensors were simultaneously employed to monitor changes in plasma luminous intensity and internal gas pressure, showing that the fluctuation signals of both were consistent in shape and variation. The Schlieren method revealed the presence of periodically rising thermal bubbles around the plasma. Fourier transform spectra identified a 30 Hz low frequency and several hundred Hz high frequencies in the fluctuations of the plasma centroid, diameter, and brightness, while the piezoelectric signal contained only the low frequency. Further analysis concluded that the high frequencies originate from laser power fluctuations, while the low frequencies are caused by gas convection. As the laser power increases, the frequency of the low frequency gradually decreases to a gentle level.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"184 ","pages":"Article 112487"},"PeriodicalIF":4.6,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-18DOI: 10.1016/j.optlastec.2025.112439
Hao Li, Xiaowen Li, Zhenning Chen
An effective calibration method for a pseudo-overlapped imaging system was investigated based on pseudo-overlapped imaging. To address the restriction between field-of-view (FOV) enlargement and spatial resolution enhancement in optical monitoring, a multiview digital image correlation system based on pseudo-overlapped imaging was developed to reconstruct large movements of relatively small objects. Using a specially designed chessboard pattern, the intrinsic and extrinsic parameters of the four virtual cameras were calibrated without the need for overlapped field, which can be used in discontinuous FOVs. Consequently, the world coordinate systems of the different FOVs were reconstructed and unified. The results show that the calibration accuracy, with different stitching areas, had an error of 0.05 pixels, comparable to that of traditional multicamera systems. The effectiveness of the calibration method and the feasibility of the multiview measurement system based on overlapped imaging were validated through cylindrical translation experiments and high-speed dynamic experiments involving a ball.
{"title":"Calibration of a pseudo-overlapped imaging based multiview system for high-resolution dynamic test","authors":"Hao Li, Xiaowen Li, Zhenning Chen","doi":"10.1016/j.optlastec.2025.112439","DOIUrl":"10.1016/j.optlastec.2025.112439","url":null,"abstract":"<div><div>An effective calibration method for a pseudo-overlapped imaging system was investigated based on pseudo-overlapped imaging. To address the restriction between field-of-view (FOV) enlargement and spatial resolution enhancement in optical monitoring, a multiview digital image correlation system based on pseudo-overlapped imaging was developed to reconstruct large movements of relatively small objects. Using a specially designed chessboard pattern, the intrinsic and extrinsic parameters of the four virtual cameras were calibrated without the need for overlapped field, which can be used in discontinuous FOVs. Consequently, the world coordinate systems of the different FOVs were reconstructed and unified. The results show that the calibration accuracy, with different stitching areas, had an error of 0.05 pixels, comparable to that of traditional multicamera systems. The effectiveness of the calibration method and the feasibility of the multiview measurement system based on overlapped imaging were validated through cylindrical translation experiments and high-speed dynamic experiments involving a ball.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"184 ","pages":"Article 112439"},"PeriodicalIF":4.6,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143150272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-18DOI: 10.1016/j.optlastec.2025.112491
Chuantao Xuan , Tao Wei , Qianchen Liu, Lihao Sun, Jing Hu, Qianqian Liu, Miao Cheng, Ruirui Wang, Wanfei Li, Yun Ling, Bo Liu
Non-volatile memory based on phase-change materials can realize in-memory computing, beneficial for the breakthrough of “memory wall”. Nevertheless, achieving both rapid write/erase speeds and thermal stability poses challenges for in-memory computing, particularly in high-temperature application areas. This study introduces a novel optoelectronic hybrid phase-change memory utilizing N-doped Sb4Te material. Results show that N doped Sb4Te film has the crystallization temperature of 207.1 °C, data-retention of 156.9 °C@10-year, much smaller volume-change rate of 0.5 %, and low resistance drift coefficient (0.06 @ 85 °C, 0.12 @ 125 °C and 0.18 @ 150 °C) when the N content is 4.73 at.%. The memory device cell exhibits SET and RESET speeds of 52 ps and 13 ps, respectively, boasting a resistance ratio exceeding 100 when transitioning from the RESET to the SET state. Structural analysis reveals that N atoms can infiltrate lattice interstices, enhancing the degree of disorder in amorphous phase, effectively hindering grain growth and resulting in a minimization of grain size. This process enhances the thermal stability of amorphous N-doped Sb4Te films. Additionally, the polyhedral structure formed by Sb groups facilitates an ultrafast phase change process. Consequently, N-doped Sb4Te-based optoelectronic hybrid phase-change memory, characterized by excellent thermal stability and fast operation speed, could offer a promising solution for in-memory computing.
{"title":"N-doped Sb4Te thin film: An excellent ultrafast optoelectronic hybrid phase change memory material","authors":"Chuantao Xuan , Tao Wei , Qianchen Liu, Lihao Sun, Jing Hu, Qianqian Liu, Miao Cheng, Ruirui Wang, Wanfei Li, Yun Ling, Bo Liu","doi":"10.1016/j.optlastec.2025.112491","DOIUrl":"10.1016/j.optlastec.2025.112491","url":null,"abstract":"<div><div>Non-volatile memory based on phase-change materials can realize in-memory computing, beneficial for the breakthrough of “memory wall”. Nevertheless, achieving both rapid write/erase speeds and thermal stability poses challenges for in-memory computing, particularly in high-temperature application areas. This study introduces a novel optoelectronic hybrid phase-change memory utilizing N-doped Sb<sub>4</sub>Te material. Results show that N doped Sb<sub>4</sub>Te film has the crystallization temperature of 207.1 °C, data-retention of 156.9 °C@10-year, much smaller volume-change rate of 0.5 %, and low resistance drift coefficient (0.06 @ 85 °C, 0.12 @ 125 °C and 0.18 @ 150 °C) when the N content is 4.73 at.%. The memory device cell exhibits SET and RESET speeds of 52 ps and 13 ps, respectively, boasting a resistance ratio exceeding 100 when transitioning from the RESET to the SET state. Structural analysis reveals that N atoms can infiltrate lattice interstices, enhancing the degree of disorder in amorphous phase, effectively hindering grain growth and resulting in a minimization of grain size. This process enhances the thermal stability of amorphous N-doped Sb<sub>4</sub>Te films. Additionally, the polyhedral structure formed by Sb groups facilitates an ultrafast phase change process. Consequently, N-doped Sb<sub>4</sub>Te-based optoelectronic hybrid phase-change memory, characterized by excellent thermal stability and fast operation speed, could offer a promising solution for in-memory computing.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"184 ","pages":"Article 112491"},"PeriodicalIF":4.6,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-18DOI: 10.1016/j.optlastec.2024.112342
Robbe de Mey , Spencer W. Jolly , Martin Virte
Semiconductor lasers subject to optical feedback can behave chaotically, which can be used as a source of randomness. The optical feedback, provided by mirrors at a distance, determines the characteristics of the chaos and thus the quality of the randomness. However, this fixed distance also shows itself in the intensity, an unwanted feature called the Time Delay Signature (TDS). One promising solution to suppress the TDS is using double optical feedback. We study this system numerically in this paper. In particular, we focus on the impact of the feedback phase, a sub-wavelength change in the position of the mirrors, on the TDS and chaos bandwidth (CBW) of the system. We show that by precisely setting the feedback parameters, including the feedback phases, the TDS can be suppressed, and that the feedback phase control is necessary rather than optional to robustly suppress the TDS. In addition, it is possible to suppress the TDS without loss of the CBW. At strong feedback rates the system can restabilize, and one can switch between a chaotic and steady state by changing only the feedback phase. Finally, we relate the feedback phase sensitivity to interference between the two delayed signals. This system is promising for applications of chaotic lasers as one can either suppress the TDS or increase the CBW.
{"title":"Influence of feedback phase on time delay signature and chaos bandwidth in a laser subject to dual optical feedback","authors":"Robbe de Mey , Spencer W. Jolly , Martin Virte","doi":"10.1016/j.optlastec.2024.112342","DOIUrl":"10.1016/j.optlastec.2024.112342","url":null,"abstract":"<div><div>Semiconductor lasers subject to optical feedback can behave chaotically, which can be used as a source of randomness. The optical feedback, provided by mirrors at a distance, determines the characteristics of the chaos and thus the quality of the randomness. However, this fixed distance also shows itself in the intensity, an unwanted feature called the Time Delay Signature (TDS). One promising solution to suppress the TDS is using double optical feedback. We study this system numerically in this paper. In particular, we focus on the impact of the feedback phase, a sub-wavelength change in the position of the mirrors, on the TDS and chaos bandwidth (CBW) of the system. We show that by precisely setting the feedback parameters, including the feedback phases, the TDS can be suppressed, and that the feedback phase control is necessary rather than optional to robustly suppress the TDS. In addition, it is possible to suppress the TDS without loss of the CBW. At strong feedback rates the system can restabilize, and one can switch between a chaotic and steady state by changing only the feedback phase. Finally, we relate the feedback phase sensitivity to interference between the two delayed signals. This system is promising for applications of chaotic lasers as one can either suppress the TDS or increase the CBW.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"184 ","pages":"Article 112342"},"PeriodicalIF":4.6,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-17DOI: 10.1016/j.optlastec.2025.112465
Nikolay N. Davletshin , Andrey M. Vyunishev , Anatoly S. Chirkin
Light-field microscopy techniques inherently suffer from image degradation outside the imaging system’s depth-of-field (DOF). Deviation from the correct imaging system’s focal plane resulted in a loss of resolution and distortion of image details. Here, we present a ghost imaging microscopy which is based on spatial intensity correlations of the light field. Ghost imaging microscopy allows us to overcome the limitations connected with the objective focusing tolerance leading to unprecedented high DOF. The obtained results promote the route to imaging volumetric microscopic structures up to several millimeters long.
{"title":"Ghost imaging microscopy: Towards to three dimensional extended depth-of-field imaging","authors":"Nikolay N. Davletshin , Andrey M. Vyunishev , Anatoly S. Chirkin","doi":"10.1016/j.optlastec.2025.112465","DOIUrl":"10.1016/j.optlastec.2025.112465","url":null,"abstract":"<div><div>Light-field microscopy techniques inherently suffer from image degradation outside the imaging system’s depth-of-field (DOF). Deviation from the correct imaging system’s focal plane resulted in a loss of resolution and distortion of image details. Here, we present a ghost imaging microscopy which is based on spatial intensity correlations of the light field. Ghost imaging microscopy allows us to overcome the limitations connected with the objective focusing tolerance leading to unprecedented high DOF. The obtained results promote the route to imaging volumetric microscopic structures up to several millimeters long.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"184 ","pages":"Article 112465"},"PeriodicalIF":4.6,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-17DOI: 10.1016/j.optlastec.2025.112414
Chaofan Yang , Dian Duan , Fan Zou , Kuo Liu , Ruibo Jin , Zechuan Liu , Haoyu Wu
We report on the noise properties of high-energy mid-infrared supercontinuum (MIR-SC) generation in normal dispersion multimode fibers from the numerical perspective. Unlike previous investigations centered on single-mode MIR-SC, the intermodal energy transfer and nonlinear coupling effects can offer a promising strategy to enhance first-order phase coherence of certain wavelengths at specific fiber modes, even amidst the coherence degradation of overall multimode MIR-SC. Lumped processing techniques are employed here to demonstrate that the noise amplification in multi-modes is still primarily due to the stimulated Raman scattering (SRS) effect. This leads to the emergence of “incoherent cloud formation” and “incoherent optical wave breaking”, similar to those observed in single-mode fibers. Increasing the pump technical noise from 0.1 % to 1 % significantly shortens the lumped coherence length and exacerbates the influence of incoherent broadening dynamics competing with coherent dynamics, resulting in MIR-SC being a strong consistency in the collapse evolution of amplitude noise and phase coherence. To minimize this noise amplification and achieve high-energy low-noise MIR-SC in practical applications, it is essential to use short-pulse pumping with low amplitude noise, ensuring that ≫ (where denotes the optical wave breaking length).
{"title":"Numerical insights into noise amplification of high-energy mid-infrared supercontinuum generation in normal dispersion multimode fibers","authors":"Chaofan Yang , Dian Duan , Fan Zou , Kuo Liu , Ruibo Jin , Zechuan Liu , Haoyu Wu","doi":"10.1016/j.optlastec.2025.112414","DOIUrl":"10.1016/j.optlastec.2025.112414","url":null,"abstract":"<div><div>We report on the noise properties of high-energy mid-infrared supercontinuum (MIR-SC) generation in normal dispersion multimode fibers from the numerical perspective. Unlike previous investigations centered on single-mode MIR-SC, the intermodal energy transfer and nonlinear coupling effects can offer a promising strategy to enhance first-order phase coherence of certain wavelengths at specific fiber modes, even amidst the coherence degradation of overall multimode MIR-SC. Lumped processing techniques are employed here to demonstrate that the noise amplification in multi-modes is still primarily due to the stimulated Raman scattering (SRS) effect. This leads to the emergence of “incoherent cloud formation” and “incoherent optical wave breaking”, similar to those observed in single-mode fibers. Increasing the pump technical noise from 0.1 % to 1 % significantly shortens the lumped coherence length <span><math><msub><mi>L</mi><mi>C</mi></msub></math></span> and exacerbates the influence of incoherent broadening dynamics competing with coherent dynamics, resulting in MIR-SC being a strong consistency in the collapse evolution of amplitude noise and phase coherence. To minimize this noise amplification and achieve high-energy low-noise MIR-SC in practical applications, it is essential to use short-pulse pumping with low amplitude noise, ensuring that <span><math><msub><mi>L</mi><mi>C</mi></msub></math></span> ≫ <span><math><msub><mi>L</mi><mrow><mi>OWB</mi></mrow></msub></math></span> (where <span><math><msub><mi>L</mi><mrow><mi>OWB</mi></mrow></msub></math></span> denotes the optical wave breaking length).</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"184 ","pages":"Article 112414"},"PeriodicalIF":4.6,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-17DOI: 10.1016/j.optlastec.2025.112461
Xianmeng Tu , Tian Qin , Xiaoyuan Ji , Zeming Wang , Jialong Chen , Zejun Zhang , Zhiguo Wang , Wei Wang , Yingxiong Qin , Jianxin Zhou
Laser cutting, as an efficient, high-quality, non-contact metal cutting technology, has the potential to replace traditional manufacturing processes for Zircaloy-4 (Zr-4 alloy) cladding materials of nuclear reactors. However, the stability of the laser cutting process has a significant impact on the quality and service safety of Zr-4 alloy and its key components in nuclear engineering. Therefore, this work first proposes a novel approach for recognizing abnormal fluctuations in the laser cutting process using cutting edge morphology characteristics, thereby ensuring the stability of the process. Firstly, the cutting edge images are captured using an ultra-depth of field microscopy, and the edge morphology feature parameters (the length (L) of vertical striations, the inclination angle (θ) of inclined striations, and surface roughness (Ra)) are measured. Secondly, a density-based spatial clustering of applications with noise (DBSCAN) model for process parameter inversion is established with only 2 cutting edge feature parameters (L and θ, Comprising 386 pairs of data) as model input. Then, a three-standard fusion method is proposed to optimize the model and the model can identify process parameters (laser power, defocus amount, cutting speed, and auxiliary gas pressure, etc.) abnormal fluctuations at 80% accuracy. Finally, by incorporating Ra as an additional input feature parameter along with L and θ, the model can identify process parameters abnormal fluctuations at 100% accuracy. This work effectively recognizes abnormal fluctuations of process parameters during laser cutting of Zr-4 cladding materials, thus benefiting the control of these fluctuations and quality management in metal sheet laser cutting.
{"title":"DBSCAN clustering model for parameter inversion using laser cutting edge morphology characteristic in Zr-4 alloy","authors":"Xianmeng Tu , Tian Qin , Xiaoyuan Ji , Zeming Wang , Jialong Chen , Zejun Zhang , Zhiguo Wang , Wei Wang , Yingxiong Qin , Jianxin Zhou","doi":"10.1016/j.optlastec.2025.112461","DOIUrl":"10.1016/j.optlastec.2025.112461","url":null,"abstract":"<div><div>Laser cutting, as an efficient, high-quality, non-contact metal cutting technology, has the potential to replace traditional manufacturing processes for Zircaloy-4 (Zr-4 alloy) cladding materials of nuclear reactors. However, the stability of the laser cutting process has a significant impact on the quality and service safety of Zr-4 alloy and its key components in nuclear engineering. Therefore, this work first proposes a novel approach for recognizing abnormal fluctuations in the laser cutting process using cutting edge morphology characteristics, thereby ensuring the stability of the process. Firstly, the cutting edge images are captured using an ultra-depth of field microscopy, and the edge morphology feature parameters (the length (<em>L</em>) of vertical striations, the inclination angle (<em>θ</em>) of inclined striations, and surface roughness (<em>Ra</em>)) are measured. Secondly, a density-based spatial clustering of applications with noise (DBSCAN) model for process parameter inversion is established with only 2 cutting edge feature parameters (<em>L</em> and <em>θ</em>, Comprising 386 pairs of data) as model input. Then, a three-standard fusion method is proposed to optimize the model and the model can identify process parameters (laser power, defocus amount, cutting speed, and auxiliary gas pressure, etc.) abnormal fluctuations at 80% accuracy. Finally, by incorporating <em>Ra</em> as an additional input feature parameter along with <em>L</em> and <em>θ</em>, the model can identify process parameters abnormal fluctuations at 100% accuracy. This work effectively recognizes abnormal fluctuations of process parameters during laser cutting of Zr-4 cladding materials, thus benefiting the control of these fluctuations and quality management in metal sheet laser cutting.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"184 ","pages":"Article 112461"},"PeriodicalIF":4.6,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143149665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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