Photonics最新文献_第7页

Efficient Writing of Fiber Bragg Gratings with Low Energy Focused fs Pulses Using a Two-Mask Interferometer 使用双掩膜干涉仪用低能量聚焦 fs 脉冲高效写入光纤布拉格光栅

IF 2.1 4区物理与天体物理

Photonics Pub Date : 2024-07-04 DOI: 10.3390/photonics11070639

François Ouellette

引用次数: 0

Beyond 100G: All-Optical Processor for High-Capacity Access~Networks 超越 100G：面向大容量接入~网络的全光处理器

IF 2.1 4区物理与天体物理

Photonics Pub Date : 2024-07-04 DOI: 10.3390/photonics11070640

George Brestas, Giannis Kanakis, M. Spyropoulou, H. Avramopoulos

引用次数: 0

On the Origin of the Photoplethysmography Signal: Modeling of Volumetric and Aggregation Effects 光敏血压信号的起源：体积和聚集效应建模

IF 2.1 4区物理与天体物理

Photonics Pub Date : 2024-07-03 DOI: 10.3390/photonics11070637

D. Lapitan, A. Tarasov, M. E. Shtyflyuk, Dmitry A. Rogatkin

{"title":"On the Origin of the Photoplethysmography Signal: Modeling of Volumetric and Aggregation Effects","authors":"D. Lapitan, A. Tarasov, M. E. Shtyflyuk, Dmitry A. Rogatkin","doi":"10.3390/photonics11070637","DOIUrl":"https://doi.org/10.3390/photonics11070637","url":null,"abstract":"This study aimed to examine the mechanisms of the photoplethysmography (PPG) signal formation using Monte Carlo simulations of light transport in biological tissues and experimental observations. Based on a three-layer skin model in backscattering geometry, we sequentially simulated volumetric blood changes and the aggregation/disaggregation of erythrocytes in the dermal layer and estimated their contribution to the registered PPG signal. The calculations were conducted for two wavelengths: 525 nm and 810 nm. For green light, absorption predominates over scattering in the formation of a PPG signal, whereas, for near-infrared light, scattering prevails over absorption. This theoretical result was verified using the Modified Beer–Lambert law and clinical in vivo PPG data of seven healthy subjects. Changes in the size of the scatterers during erythrocyte aggregation and disaggregation can significantly contribute to the PPG signal at near-infrared light. Thus, for the green waveband, the classical volumetric model can be considered dominant in the PPG signal formation. In contrast, for the near-infrared range, both volumetric and aggregation effects must be considered as being approximately equal.","PeriodicalId":20154,"journal":{"name":"Photonics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141682143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Design of an Airborne Low-Light Imaging System Based on Multichannel Optical Butting 基于多通道光学对接的机载微光成像系统设计

IF 2.1 4区物理与天体物理

Photonics Pub Date : 2024-07-03 DOI: 10.3390/photonics11070636

Jianwei Peng, Hongtao Yang, Yangjie Lei, Wanrong Yu, Weining Chen, Guangdong Zhang

{"title":"Design of an Airborne Low-Light Imaging System Based on Multichannel Optical Butting","authors":"Jianwei Peng, Hongtao Yang, Yangjie Lei, Wanrong Yu, Weining Chen, Guangdong Zhang","doi":"10.3390/photonics11070636","DOIUrl":"https://doi.org/10.3390/photonics11070636","url":null,"abstract":"For the purpose of achieving long-range, high-resolution, and ultra-wide-swath airborne earth imaging at extremely low-light levels (0.01 Lux), a low-light imaging system built on multi-detector optical butting was researched. Having decomposed the system’s specifications and verified its low-light imaging capability, we proposed to employ an optical system with a large relative aperture and low distortion and achieve imaging through the field-of-view (FOV) butting facilitated by eight 1080P high-sensitivity scientific complementary metal-oxide semiconductor (SCMOS) detectors. This paper elaborates on the design concept of the mechanical configuration of the imaging system; studies the calculation method of the structural parameters of the reflection prism; provides mathematical expressions for geometric parameters, such as the length and width of the splicing prism; and designs in detail the splicing structure of six reflection prisms for eight-channel beam splitting. Based on the design and computational results, a high-resolution, wide-swath imaging system for an ambient illuminance of 0.01 Lux was developed. Exhibiting a ground sampling distance (GSD) of 0.5 m (at a flight height of 5 km), this low-light imaging system keeps the FOV overlap ratio between adjacent detectors below 3% and boasts an effective image resolution of 4222 × 3782. The results from flight testing revealed that the proposed imaging system is capable of generating wide-swath, high-contrast resolution imagery under airborne and low-light conditions. As such, the way the system is prepared can serve as a reference point for the development of airborne low-light imaging devices.","PeriodicalId":20154,"journal":{"name":"Photonics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141683854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Suppression Effect of an Imaging System on the Geometric Tilt-to-Length Coupling in a Test Mass Interferometer 成像系统对试验质量干涉仪几何倾斜-长度耦合的抑制效应

IF 2.1 4区物理与天体物理

Photonics Pub Date : 2024-07-03 DOI: 10.3390/photonics11070638

Jia Shen, Shaoxin Wang, Keqi Qi, Mengyang Zhao, Heshan Liu, Ran Yang, Pan Li, Wei Tao, Ziren Luo, Ruihong Gao

{"title":"The Suppression Effect of an Imaging System on the Geometric Tilt-to-Length Coupling in a Test Mass Interferometer","authors":"Jia Shen, Shaoxin Wang, Keqi Qi, Mengyang Zhao, Heshan Liu, Ran Yang, Pan Li, Wei Tao, Ziren Luo, Ruihong Gao","doi":"10.3390/photonics11070638","DOIUrl":"https://doi.org/10.3390/photonics11070638","url":null,"abstract":"Tilt-to-length (TTL) coupling noise arises from angular misalignments of interfering beams in optical path length (OPL) measurements and significantly impacts the accuracy of interferometry measurement systems. This paper focuses on geometric TTL coupling in a test mass (TM) interferometer and examines how an imaging system influences TTL noise suppression. First, the analytical expression of the geometric TTL coupling in a TM interferometer with alignment errors is derived and confirmed through numerical simulation. Subsequently, an imaging system is incorporated into the geometric model and the corresponding analytical expressions are obtained under two common conjugate relationships. Nevertheless, the TTL coupling remains beyond the requirement of TM interferometer, as the residual TTL coupled with alignment errors persists even with the imaging system. Therefore, an optimal position of the imaging system capable of eliminating the second-order term of the TTL coupling is determined. Meanwhile, the first-order term can be mitigated through in-orbit calibrations. These findings offer valuable guidance for the design and adjustment of imaging systems in space-borne gravitational wave detection missions, which require high-precision laser interferometry.","PeriodicalId":20154,"journal":{"name":"Photonics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141680401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Highly Sensitive Optical Fiber MZI Sensor for Specific Detection of Trace Pb2+ Ion Concentration 用于特异性检测痕量 Pb2+ 离子浓度的高灵敏度光纤 MZI 传感器

IF 2.1 4区物理与天体物理

Photonics Pub Date : 2024-07-02 DOI: 10.3390/photonics11070631

Lijie Zhang, Hongbin He, Shangpu Zhang, Yanling Xiong, Rui Pan, Wenlong Yang

{"title":"Highly Sensitive Optical Fiber MZI Sensor for Specific Detection of Trace Pb2+ Ion Concentration","authors":"Lijie Zhang, Hongbin He, Shangpu Zhang, Yanling Xiong, Rui Pan, Wenlong Yang","doi":"10.3390/photonics11070631","DOIUrl":"https://doi.org/10.3390/photonics11070631","url":null,"abstract":"A novel chitosan (CS) functionalized optical fiber sensor with a bullet-shaped hollow cavity was proposed in this work for the trace concentration of Pb2+ ion detection in the water environment. The sensor is an optical fiber Mach–Zehnder interferometer (MZI), which consists of a sequentially spliced bullet-shaped hollow-core fiber (HCF), thin-core fiber, and another piece of spliced bullet-shaped HCF. The hollow-core fiber is caused to collapse by adjusting the amount of discharge to form a tapered hollow cavity with asymmetric end faces. The bullet-like hollow cavities act as beam expanders and couplers for optical fiber sensors, which were symmetrically spliced at both ends of a section of thin core fiber. The simulation and experiments show that the bullet-like hollow-core tapered cavity excites more cladding modes and is more sensitive to variation in the external environment than the planar and spherical cavities. The ion-imprinted chitosan (IIP-CS) film was fabricated with Pb2+ ion as a template and uniformly coated on the surface for specific recognition of Pb2+. Experimental verification confirms that the developed sensor can achieve high-sensitivity Pb2+ ion detection, with a sensitivity of up to −12.68 pm/ppm and a minimum Pb2+ ion detection concentration of 5.44 ppb Meanwhile, the sensor shows excellent selectivity, repeatability, and stability in the ion detection process, which has huge potential in the direction of heavy metal ion detection in the future.","PeriodicalId":20154,"journal":{"name":"Photonics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141687516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Transcutaneous Transmission of Light of Photobiomodulation Therapy Wavelengths at 808 nm, 915 nm, 975 nm, and 1064 nm to the Spinal Canal of Cadaver Dogs 波长为 808 nm、915 nm、975 nm 和 1064 nm 的光生物调节疗法光线经皮传输至尸体狗的椎管

IF 2.1 4区物理与天体物理

Photonics Pub Date : 2024-07-02 DOI: 10.3390/photonics11070632

Daqing Piao, Lara A. Sypniewski, Kenneth E. Bartels, Daniel J. Burba, Luis De Taboada

{"title":"Transcutaneous Transmission of Light of Photobiomodulation Therapy Wavelengths at 808 nm, 915 nm, 975 nm, and 1064 nm to the Spinal Canal of Cadaver Dogs","authors":"Daqing Piao, Lara A. Sypniewski, Kenneth E. Bartels, Daniel J. Burba, Luis De Taboada","doi":"10.3390/photonics11070632","DOIUrl":"https://doi.org/10.3390/photonics11070632","url":null,"abstract":"This study compared the transcutaneous target level irradiances from the thoracic to lumbar segments of the interior spinal canal in three cadaver dogs, measured for light at four wavelengths (808 nm, 915 nm, 975 nm, and 1064 nm), common in photobiomodulation therapy (PBMT). Intra-spinal irradiances at nine sites spanning approximately 8 cm in length were measured using a flexible intra-spinal probe under surface application of continuous-wave (CW) light with powers ranging from 0.5 W to 2 W. Surface illumination was applied using an acupuncture treatment head in three modes: non-contact with skin removed, non-contact with skin intact, and contact with skin intact. During surface application, the treatment head was positioned over the spinal canal near the 13th vertebrae (T13, surface site 1), and approximately 4 cm (surface site 5) and 8 cm (surface site 9) caudal to T13. At each position of the treatment head, the light was multiplexed among the four wavelengths at the same power setting. In all three modes of surface application, the target level irradiance at the 1064 nm wavelength was significantly greater than that at the other three wavelengths (p ≤ 0.0017). At a surface irradiance of ~157 mW/cm2, corresponding to 0.5 W light applied with the treatment head directly in contact with the skin, the intra-spinal irradiance at 1064 nm reached 0.137 ± 0.095 mW/cm2. Obtaining a dosage of PBMT-associative wavelengths of this magnitude at the level of the spinal canal may guide focused research into the transcutaneous applicability of PBMT for spinal cord injuries.","PeriodicalId":20154,"journal":{"name":"Photonics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141687444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Repeatability of Subjective Refraction in Different Age Groups 不同年龄组主观屈光度数的重复性

IF 2.1 4区物理与天体物理

Photonics Pub Date : 2024-07-02 DOI: 10.3390/photonics11070634

Carlos Carpena-Torres, Laura Batres, María Serramito, Gonzalo Carracedo

{"title":"Repeatability of Subjective Refraction in Different Age Groups","authors":"Carlos Carpena-Torres, Laura Batres, María Serramito, Gonzalo Carracedo","doi":"10.3390/photonics11070634","DOIUrl":"https://doi.org/10.3390/photonics11070634","url":null,"abstract":"Background: The purpose of this study was to assess the inter-examiner repeatability of subjective refraction across diverse age cohorts, an aspect not previously investigated. Methods: A cross-sectional, randomized study enrolled 86 participants (mean age: 37.0 ± 18.0 years), distributed into three groups: youth, non-presbyopic adults, and presbyopic adults. Each participant underwent three subjective refractions by three different optometrists on separate days. Repeatability analysis encompassed all refractive variables (M, J0, and J45). Results: There were no significant differences between optometrists in all refractive variables for either the overall sample or across age groups (p ≥ 0.05). Additionally, no correlation was found between participants’ age and the mean difference in refractive variables across optometrists (p ≥ 0.05). The 95% confidence interval of repeatability (r) for the total sample was ±0.70 D for M, ±0.29 for J0, and ±0.21 D for J45. Conclusions: Based on these findings and previous research, it is suggested to establish 95% limits of agreement of ±0.75 D for M, and between ±0.25 D and ±0.50 D for both J0 and J45 when validating new refraction systems compared to subjective refraction as the gold standard, regardless of the age of the subjects evaluated.","PeriodicalId":20154,"journal":{"name":"Photonics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141687345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Demonstration of a Low-SWaP Terminal for Ground-to-Air Single-Mode Fiber Coupled Laser Links 用于地对空单模光纤耦合激光链路的低 SWaP 终端演示

IF 2.1 4区物理与天体物理

Photonics Pub Date : 2024-07-02 DOI: 10.3390/photonics11070633

A. McCann, Alex M. Frost, S. Karpathakis, B. Dix-Matthews, D. Gozzard, Shane Walsh, S. Schediwy

{"title":"Demonstration of a Low-SWaP Terminal for Ground-to-Air Single-Mode Fiber Coupled Laser Links","authors":"A. McCann, Alex M. Frost, S. Karpathakis, B. Dix-Matthews, D. Gozzard, Shane Walsh, S. Schediwy","doi":"10.3390/photonics11070633","DOIUrl":"https://doi.org/10.3390/photonics11070633","url":null,"abstract":"Free space optical technology promises to revolutionize point-to-point communications systems. By taking advantage of their vastly higher frequencies, coherent optical systems outperform their radio counterparts by orders of magnitude in achievable data throughput, while simultaneously lowering the required size, weight, and power (SWaP), making them ideal for mobile applications. However, the widespread implementation of this technology has been largely hindered by the effects of atmospheric turbulence, often necessitating complex higher-order adaptive optics systems that are largely unsuitable for deployment on mobile platforms. By employing tip/tilt beam-stabilization, we present the results of a bespoke low-SWaP optical terminal that demonstrated single-mode fiber (SMF) coupling. This was achieved by autonomously acquiring and tracking the targets using a combination of aircraft transponder and machine vision feedback to a root-mean-square (RMS) tracking error of 29.4 µrad and at angular rates of up to 0.83 deg/s. To the authors’ knowledge, these works constitute the first published SMF coupled optical link to a full-sized helicopter, and we describe derived quantities relevant to the future refinement of such links. The ability to achieve SMF coupling without the constraints of complex adaptive optics systems positions this technology as a versatile quantum-capable communications solution for land-, air-, and sea-based platforms ranging across commercial, scientific, and military operators.","PeriodicalId":20154,"journal":{"name":"Photonics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141688248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Hybrid Improved SAC-IA with a KD-ICP Algorithm for Local Point Cloud Alignment Optimization 改进型 SAC-IA 与 KD-ICP 算法混合用于局部点云对齐优化

IF 2.1 4区物理与天体物理

Photonics Pub Date : 2024-07-02 DOI: 10.3390/photonics11070635

Yinbao Cheng, Haiman Chu, Yaru Li, Yingqi Tang, Zai Luo, Shaohui Li

{"title":"A Hybrid Improved SAC-IA with a KD-ICP Algorithm for Local Point Cloud Alignment Optimization","authors":"Yinbao Cheng, Haiman Chu, Yaru Li, Yingqi Tang, Zai Luo, Shaohui Li","doi":"10.3390/photonics11070635","DOIUrl":"https://doi.org/10.3390/photonics11070635","url":null,"abstract":"To overcome incomplete point cloud data obtained from laser scanners scanning complex surfaces, multi-viewpoint cloud data needs to be aligned for use. A hybrid improved SAC-IA with a KD-ICP algorithm is proposed for local point cloud alignment optimization. The scanned point cloud data is preprocessed with statistical filtering, as well as uniform down-sampling. The sampling consistency initial alignment (SAC-IA) algorithm is improved by introducing a dissimilarity vector for point cloud initial alignment. In addition, the iterative closest point (ICP) algorithm is improved by incorporating bidirectional KD-tree to form the KD-ICP algorithm for fine point cloud alignment. Finally, the algorithms are compared in terms of runtime and alignment accuracy. The implementation of the algorithms is based on the Visual Studio 2013 software configurating point cloud library environment for testing experiments and practical experiments. The overall alignment method can be 40%~50% faster in terms of running speed. The improved SAC-IA algorithm provides better transformed poses, combined with the KD-ICP algorithm to select the corresponding nearest neighbor pairs, which improves the accuracy, as well as the applicability of the alignment.","PeriodicalId":20154,"journal":{"name":"Photonics","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141685571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0