Pub Date : 2025-01-14DOI: 10.1109/JPHOT.2025.3530086
Kang Wang;Hongyang Li;Zhuorui Zheng;Yi Liu;Ye Tian;Liwei Song
We propose and experimentally demonstrate a terahertz (THz) source based on optical rectification in lithium niobate wafers driven by an ultrafast ytterbium laser. Terahertz pulses with a repetition of 10 kHz and a spectrum of 0.1∼6 THz are generated via a collinear geometry. The phase-matching condition is analyzed and the effect of crystal thickness is investigated. Our study demonstrates a compact and stable source for terahertz spectroscopy and imaging applications.
{"title":"Collinear Terahertz Generation from LiNbO3 Wafer Driven by an Ultrafast Yb-Laser","authors":"Kang Wang;Hongyang Li;Zhuorui Zheng;Yi Liu;Ye Tian;Liwei Song","doi":"10.1109/JPHOT.2025.3530086","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3530086","url":null,"abstract":"We propose and experimentally demonstrate a terahertz (THz) source based on optical rectification in lithium niobate wafers driven by an ultrafast ytterbium laser. Terahertz pulses with a repetition of 10 kHz and a spectrum of 0.1∼6 THz are generated via a collinear geometry. The phase-matching condition is analyzed and the effect of crystal thickness is investigated. Our study demonstrates a compact and stable source for terahertz spectroscopy and imaging applications.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 1","pages":"1-5"},"PeriodicalIF":2.1,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10841949","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143106175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-10DOI: 10.1109/JPHOT.2025.3528019
Liyue Zhang;Weijie Hong;Songsui Li;Wei Pan;Lianshan Yan;Bin Luo;Xihua Zou
The human brain can efficiently handle multiple tasks simultaneously, with the structural segregation of brain regions closely linked to their functional specialization. In this paper, we propose and experimentally demonstrate multifunctional photonic reservoir computing (MPRC), inspired by this biological characteristic. The neuron states of the photonic reservoir are divided into distinct sections for different tasks by the designing of input matrix, and only a set of output weight matrix, applicable to all tasks, is ultimately trained. Therefore, MPRC is capable of handling multiple tasks simultaneously with a fixed set of parameters, mitigating the tedious process of hyperparameter optimization. The influence of neuron partition size and operating parameters on MPRC performance is studied systematically. Furthermore, the generalizability of MPRC is validated by performing four different tasks simultaneously. Finally, our results are experimentally demonstrated using semiconductor lasers with a time-delay feedback loop.
{"title":"Multifunctional Photonic Reservoir Computing Based on Semiconductor Laser With Optical Feedback","authors":"Liyue Zhang;Weijie Hong;Songsui Li;Wei Pan;Lianshan Yan;Bin Luo;Xihua Zou","doi":"10.1109/JPHOT.2025.3528019","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3528019","url":null,"abstract":"The human brain can efficiently handle multiple tasks simultaneously, with the structural segregation of brain regions closely linked to their functional specialization. In this paper, we propose and experimentally demonstrate multifunctional photonic reservoir computing (MPRC), inspired by this biological characteristic. The neuron states of the photonic reservoir are divided into distinct sections for different tasks by the designing of input matrix, and only a set of output weight matrix, applicable to all tasks, is ultimately trained. Therefore, MPRC is capable of handling multiple tasks simultaneously with a fixed set of parameters, mitigating the tedious process of hyperparameter optimization. The influence of neuron partition size and operating parameters on MPRC performance is studied systematically. Furthermore, the generalizability of MPRC is validated by performing four different tasks simultaneously. Finally, our results are experimentally demonstrated using semiconductor lasers with a time-delay feedback loop.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 1","pages":"1-7"},"PeriodicalIF":2.1,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10836813","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143106177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-08DOI: 10.1109/JPHOT.2025.3527537
Xing-Rui Ding;Zi-Hao Deng;Jia-Sheng Li;Rui-Xiang Qian;Bo-Wen Duan;Zong-Tao Li
The burgeoning advancements in Light Emitting Diode (LED) technology have opened avenues for applications beyond traditional display and lighting, notably in the realm of 3D printing. This study introduces a Local Dimming (LD) method that employs LED backlight technology to enhance the edge quality of Liquid Crystal Display (LCD) photocuring 3D printing (LPP). LPP, known for its rapid and cost-effective fabrication, faces challenges with light leakage and precision under high-power ultraviolet (UV) light. By locally adjusting the backlight array's brightness to conform to the digital mask's shape, this study effectively suppresses LCD light leakage and improves edge definition. A comprehensive investigation into the LD method's process parameters—exposure time, pixel compensation coefficient, and initial backlight calculation—reveals significant improvements in print quality. The LD method achieves up to an 81.56% enhancement in dimensional accuracy compared to the conventional full-backlight technique. This research not only addresses the intrinsic light leakage in LCDs but also facilitates the high-resolution printing of complex structures, thus expanding the utility of LED devices in additive manufacturing.
{"title":"Improving Edge Quality of Liquid Crystal Display 3D Printing Using Local Dimming Method","authors":"Xing-Rui Ding;Zi-Hao Deng;Jia-Sheng Li;Rui-Xiang Qian;Bo-Wen Duan;Zong-Tao Li","doi":"10.1109/JPHOT.2025.3527537","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3527537","url":null,"abstract":"The burgeoning advancements in Light Emitting Diode (LED) technology have opened avenues for applications beyond traditional display and lighting, notably in the realm of 3D printing. This study introduces a Local Dimming (LD) method that employs LED backlight technology to enhance the edge quality of Liquid Crystal Display (LCD) photocuring 3D printing (LPP). LPP, known for its rapid and cost-effective fabrication, faces challenges with light leakage and precision under high-power ultraviolet (UV) light. By locally adjusting the backlight array's brightness to conform to the digital mask's shape, this study effectively suppresses LCD light leakage and improves edge definition. A comprehensive investigation into the LD method's process parameters—exposure time, pixel compensation coefficient, and initial backlight calculation—reveals significant improvements in print quality. The LD method achieves up to an 81.56% enhancement in dimensional accuracy compared to the conventional full-backlight technique. This research not only addresses the intrinsic light leakage in LCDs but also facilitates the high-resolution printing of complex structures, thus expanding the utility of LED devices in additive manufacturing.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 1","pages":"1-8"},"PeriodicalIF":2.1,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10834600","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143106176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-06DOI: 10.1109/JPHOT.2025.3526152
Jianhua Sang;Haoyu Huang;Liwei Song;Ye Tian;Ruxin Li
The application of electric fields induces changes in the symmetry of crystals, which can be observed spectroscopically as variations in the even harmonic generation. In this study, we report the ultrafast modulation of GaAs crystal symmetry using strong terahertz field. The modulation is recorded by the vibration of even harmonic intensity which depends on the polarization direction and instantaneous field strength of applied terahertz wave. The interference between intrinsic even-order nonlinearity and terahertz induced polarization is analyzed. This work offers a novel approach to determining key parameters, such as crystal orientation and terahertz field strength.
{"title":"Terahertz Modulation of Even-order Polarization in GaAs","authors":"Jianhua Sang;Haoyu Huang;Liwei Song;Ye Tian;Ruxin Li","doi":"10.1109/JPHOT.2025.3526152","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3526152","url":null,"abstract":"The application of electric fields induces changes in the symmetry of crystals, which can be observed spectroscopically as variations in the even harmonic generation. In this study, we report the ultrafast modulation of GaAs crystal symmetry using strong terahertz field. The modulation is recorded by the vibration of even harmonic intensity which depends on the polarization direction and instantaneous field strength of applied terahertz wave. The interference between intrinsic even-order nonlinearity and terahertz induced polarization is analyzed. This work offers a novel approach to determining key parameters, such as crystal orientation and terahertz field strength.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 1","pages":"1-4"},"PeriodicalIF":2.1,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10829706","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143106174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-26DOI: 10.1109/JPHOT.2024.3523328
Jiarui Zhang;Yaxin Cai;Ming Fang
In turbid water environments, conventional polari-metric imaging descattering methods usually rely on selecting a non-target background region as a substitute for global back-ground light information, leading to image clarity. By integrating polarization imaging with the dark channel prior (DCP) and fully utilizing the polarization information from the Stokes vector and the DCP, the interference of the target information in calculating the background information can be effectively eliminated. This method also enables accurate estimation of the global distribution for the degree of polarization (DoP) and the angle of polarization (AoP) of the backscattered light and eliminates the need for the complex process of background region selection. Experimental results with varying turbid water concentrations demonstrate the proposed method's effectiveness for target recovery in both underwater images with and without background regions. Compared with the conventional active polarization imaging model, our method improves image contrast by 47% in the strongly scattering environment.
{"title":"Polarization Imaging Descattering Based on Dark Channel Prior Background Light Estimation","authors":"Jiarui Zhang;Yaxin Cai;Ming Fang","doi":"10.1109/JPHOT.2024.3523328","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3523328","url":null,"abstract":"In turbid water environments, conventional polari-metric imaging descattering methods usually rely on selecting a non-target background region as a substitute for global back-ground light information, leading to image clarity. By integrating polarization imaging with the dark channel prior (DCP) and fully utilizing the polarization information from the Stokes vector and the DCP, the interference of the target information in calculating the background information can be effectively eliminated. This method also enables accurate estimation of the global distribution for the degree of polarization (DoP) and the angle of polarization (AoP) of the backscattered light and eliminates the need for the complex process of background region selection. Experimental results with varying turbid water concentrations demonstrate the proposed method's effectiveness for target recovery in both underwater images with and without background regions. Compared with the conventional active polarization imaging model, our method improves image contrast by 47% in the strongly scattering environment.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 1","pages":"1-9"},"PeriodicalIF":2.1,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10816622","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142975939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-25DOI: 10.1109/JPHOT.2024.3521615
Di Xin;Nihui Zhang;Lingqian Meng;Qinghao Zhao;Weiqiao Zhang;Fengxin Dong;Xuyan Zhou;Hongbo Zhang;Wanhua Zheng
Broad-area 976 nm semiconductor lasers have garnered widespread attention for their applications in generating high-power 488 nm blue laser light and as pump sources for solid-state and ytterbium-doped fiber lasers. Nevertheless, these lasers exhibit a wide gain bandwidth, short cavity length, and usually use the natural cleavage surface as the output window, resulting in a broad emitting spectrum in free-running state. We investigated a high-power narrow-linewidth 976 nm edge emitting broad area semiconductor laser (EEL) through external cavity feedback technology by employing a transmission grating as the dispersive element. This configuration achieved a high output power of 11 W and a spectral linewidth of 0.36 nm at 976 nm, corresponding to an intracavity power of 15.7 W. It provided a more flexible cavity structure for direct frequency doubling of the semiconductor laser to generate a high power of 488 nm blue laser.
{"title":"Spectra Narrowing of a 976 nm High Power External-Cavity Semiconductor Laser Based on a Transmission Grating","authors":"Di Xin;Nihui Zhang;Lingqian Meng;Qinghao Zhao;Weiqiao Zhang;Fengxin Dong;Xuyan Zhou;Hongbo Zhang;Wanhua Zheng","doi":"10.1109/JPHOT.2024.3521615","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3521615","url":null,"abstract":"Broad-area 976 nm semiconductor lasers have garnered widespread attention for their applications in generating high-power 488 nm blue laser light and as pump sources for solid-state and ytterbium-doped fiber lasers. Nevertheless, these lasers exhibit a wide gain bandwidth, short cavity length, and usually use the natural cleavage surface as the output window, resulting in a broad emitting spectrum in free-running state. We investigated a high-power narrow-linewidth 976 nm edge emitting broad area semiconductor laser (EEL) through external cavity feedback technology by employing a transmission grating as the dispersive element. This configuration achieved a high output power of 11 W and a spectral linewidth of 0.36 nm at 976 nm, corresponding to an intracavity power of 15.7 W. It provided a more flexible cavity structure for direct frequency doubling of the semiconductor laser to generate a high power of 488 nm blue laser.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 1","pages":"1-6"},"PeriodicalIF":2.1,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10814083","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In GaN-based vertical-cavity surface-emitting lasers (VCSELs) with insulator-buried structure, the strong index guiding will introduce higher order modes. In this paper, we present a novel GaN-based VCSEL with a tapered SiO 2 -buried structure by numerical simulations. Compared to conventional flat aperture VCSELs, tapered aperture VCSELs show the lower threshold current and higher slope efficiency, and can be attributed to the improvement of current distribution within the current injection aperture. Moreover, by adjusting the taper length, the current distribution in current injection aperture can be further changed, enabling single fundamental mode lasing. Additionally, the modulation bandwidth for tapered aperture VCSELs will also increase due to the reduction of parasitic capacitance. This research guides the development of high performance GaN VCSELs capable of achieving single transverse mode and high modulation rates for visible optical communication links and networks.
{"title":"Performance Improvement of GaN-Based Vertical-Cavity Surface-Emitting Lasers by Using Tapered SiO2-Buried Structure","authors":"Rongbin Xu;Yachao Wang;Mingchao Fang;Yang Mei;Leiying Ying;Daquan Yu;Baoping Zhang","doi":"10.1109/JPHOT.2024.3522498","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3522498","url":null,"abstract":"In GaN-based vertical-cavity surface-emitting lasers (VCSELs) with insulator-buried structure, the strong index guiding will introduce higher order modes. In this paper, we present a novel GaN-based VCSEL with a tapered SiO\u0000<sub>2</sub>\u0000-buried structure by numerical simulations. Compared to conventional flat aperture VCSELs, tapered aperture VCSELs show the lower threshold current and higher slope efficiency, and can be attributed to the improvement of current distribution within the current injection aperture. Moreover, by adjusting the taper length, the current distribution in current injection aperture can be further changed, enabling single fundamental mode lasing. Additionally, the modulation bandwidth for tapered aperture VCSELs will also increase due to the reduction of parasitic capacitance. This research guides the development of high performance GaN VCSELs capable of achieving single transverse mode and high modulation rates for visible optical communication links and networks.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 1","pages":"1-5"},"PeriodicalIF":2.1,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10815608","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-24DOI: 10.1109/JPHOT.2024.3521430
Arvind Kumar;Nikumani Choudhury;Jayendra N. Bandyopadhyay;S. M. Zafaruddin
Signal transmission over underwater optical wireless communication (UOWC) experiences the combined effect of oceanic turbulence and pointing errors statistically modeled using the sum of two Meijer-G functions. There is a research gap in the exact statistical analysis of multi-aperture UOWC systems that use selection combining diversity techniques to enhance performance compared to single-aperture systems. In this paper, we develop a general framework for the continued product and positive integer exponent for the sum of Meijer-G functions to analyze the exact statistical performance of the UOWC system in terms of multivariate Fox-H function for both independent and non-identically distributed (i.ni.d.) and independent and identically distributed (i.i.d.) channels. We also approximate the performance of a multi-aperture UOWC system with i.i.d. channels using the single-variate Fox-H function. Using the generalized approach, we present analytical expressions for average bit-error rate (BER) and ergodic capacity for the considered system operating over exponential–generalized gamma (EGG) oceanic turbulence combined with zero-boresight pointing errors. We also develop asymptotic expressions for the average BER at a high signal-to-noise (SNR) to capture insights into the system's performance. Our simulation findings confirm the accuracy of our derived expressions and illustrate the impact of turbulence parameters for i.ni.d. and i.i.d. models for the average BER and ergodic capacity, which may provide a better estimate for the efficient deployment of UOWC.
{"title":"Meijer-G Function With Continued Product and Integer Exponent: Performance of Multi-Aperture UOWC System Over EGG Turbulence","authors":"Arvind Kumar;Nikumani Choudhury;Jayendra N. Bandyopadhyay;S. M. Zafaruddin","doi":"10.1109/JPHOT.2024.3521430","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3521430","url":null,"abstract":"Signal transmission over underwater optical wireless communication (UOWC) experiences the combined effect of oceanic turbulence and pointing errors statistically modeled using the sum of two Meijer-G functions. There is a research gap in the exact statistical analysis of multi-aperture UOWC systems that use selection combining diversity techniques to enhance performance compared to single-aperture systems. In this paper, we develop a general framework for the continued product and positive integer exponent for the sum of Meijer-G functions to analyze the exact statistical performance of the UOWC system in terms of multivariate Fox-H function for both independent and non-identically distributed (i.ni.d.) and independent and identically distributed (i.i.d.) channels. We also approximate the performance of a multi-aperture UOWC system with i.i.d. channels using the single-variate Fox-H function. Using the generalized approach, we present analytical expressions for average bit-error rate (BER) and ergodic capacity for the considered system operating over exponential–generalized gamma (EGG) oceanic turbulence combined with zero-boresight pointing errors. We also develop asymptotic expressions for the average BER at a high signal-to-noise (SNR) to capture insights into the system's performance. Our simulation findings confirm the accuracy of our derived expressions and illustrate the impact of turbulence parameters for i.ni.d. and i.i.d. models for the average BER and ergodic capacity, which may provide a better estimate for the efficient deployment of UOWC.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 2","pages":"1-15"},"PeriodicalIF":2.1,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10814056","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-23DOI: 10.1109/JPHOT.2024.3520988
Keita Yamaguchi;Kenya Suzuki;Osamu Moriwaki
In response to the rapid growth in traffic, the throughput and handling unit size of optical network nodes have been increasing at a rate of approximately ten times per decade. To achieve such high node throughputs, it is important to expand the wavelength bandwidth and support more WDM fibers. Therefore, the transponder aggregator (TPA) that provides the colorless, directionless, and contentionless (CDC) function of the network node also needs to respond to these changes. As a TPA suitable for such ultra-high throughput reconfigurable optical add/drop multiplexing (ROADM) nodes, we propose a multicast switch (MCS) that consists of 1 × N splitters and M × 1 switches facing each other and utilizes a silica-based planar lightwave circuit (PLC) platform. The CDC-ROADM nodes have a trade-off between the number of connected WDM fibers and the number of transponders that can be accommodated by a single TPA. Therefore, increasing the WDM fibers results in a decrease in the transponders that can be accommodated by a single MCS, but at the same time reduces the splitting loss in that switch. As a result, the number of optical amplifiers used for add/drop functions can be reduced. In addition, because the handling unit is larger, the increase in the number of required MCS units is limited, and highly integrated PLC-based MCSs become practical. In this paper, we demonstrate MCSs supporting 300-nm bandwidth and 32- and 64-degree nodes for the first time ever. The insertion loss of the prototype was less than 8.0 dB in all paths, including connections with common single-mode fiber, and the extinction ratio was greater than 40 dB.
{"title":"Transponder Aggregator for CDC-ROADM Nodes Supporting S-U Bands and 32/64-WDM Ports","authors":"Keita Yamaguchi;Kenya Suzuki;Osamu Moriwaki","doi":"10.1109/JPHOT.2024.3520988","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3520988","url":null,"abstract":"In response to the rapid growth in traffic, the throughput and handling unit size of optical network nodes have been increasing at a rate of approximately ten times per decade. To achieve such high node throughputs, it is important to expand the wavelength bandwidth and support more WDM fibers. Therefore, the transponder aggregator (TPA) that provides the colorless, directionless, and contentionless (CDC) function of the network node also needs to respond to these changes. As a TPA suitable for such ultra-high throughput reconfigurable optical add/drop multiplexing (ROADM) nodes, we propose a multicast switch (MCS) that consists of 1 × N splitters and M × 1 switches facing each other and utilizes a silica-based planar lightwave circuit (PLC) platform. The CDC-ROADM nodes have a trade-off between the number of connected WDM fibers and the number of transponders that can be accommodated by a single TPA. Therefore, increasing the WDM fibers results in a decrease in the transponders that can be accommodated by a single MCS, but at the same time reduces the splitting loss in that switch. As a result, the number of optical amplifiers used for add/drop functions can be reduced. In addition, because the handling unit is larger, the increase in the number of required MCS units is limited, and highly integrated PLC-based MCSs become practical. In this paper, we demonstrate MCSs supporting 300-nm bandwidth and 32- and 64-degree nodes for the first time ever. The insertion loss of the prototype was less than 8.0 dB in all paths, including connections with common single-mode fiber, and the extinction ratio was greater than 40 dB.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 1","pages":"1-7"},"PeriodicalIF":2.1,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10812056","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142905757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A three-dimensional (3D) particle image velocimetry (PIV) system typically consists of multiple cameras. However, micro-PIV systems for measuring microscale velocity fields lack sufficient space to accommodate them. In this work we propose an alternative approach based on computational imaging, enabling monocular micro-PIV systems to perform 3D flow field measurements without additional hardware or complex structure. The microscopic objective is designed to satisfy the required parameters, and the point spread function (PSF) responses of the system to different depths of the object surface are obtained. Additionally, a particle dataset generation method based on the PSFs of the optical system is proposed, and a deep-learning network is constructed for training. To validate the feasibility, particle images are captured in experiments and inputted into the network to reconstruct depth images and build three-dimensional flow fields. Simulation and experimental results demonstrate that the measurement deviation is within 13.2%, indicating the practicality of the proposed model.
{"title":"Monocular 3D Micro-PIV System Using Computational Imaging","authors":"Taiyuange Lou;Chengxiang Guo;Tong Yang;Lei Yang;Hongbo Xie","doi":"10.1109/JPHOT.2024.3520163","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3520163","url":null,"abstract":"A three-dimensional (3D) particle image velocimetry (PIV) system typically consists of multiple cameras. However, micro-PIV systems for measuring microscale velocity fields lack sufficient space to accommodate them. In this work we propose an alternative approach based on computational imaging, enabling monocular micro-PIV systems to perform 3D flow field measurements without additional hardware or complex structure. The microscopic objective is designed to satisfy the required parameters, and the point spread function (PSF) responses of the system to different depths of the object surface are obtained. Additionally, a particle dataset generation method based on the PSFs of the optical system is proposed, and a deep-learning network is constructed for training. To validate the feasibility, particle images are captured in experiments and inputted into the network to reconstruct depth images and build three-dimensional flow fields. Simulation and experimental results demonstrate that the measurement deviation is within 13.2%, indicating the practicality of the proposed model.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 1","pages":"1-9"},"PeriodicalIF":2.1,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10806749","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142905758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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