Jie He, Jianxin Wang, Wei Liu, Xili Lu, Jingwei Lv, Lin Yang, Paul K. Chu, Chao Liu
{"title":"Photonic crystal fiber based on graphene surface plasmon resonance for high-sensitivity terahertz refractive index sensing","authors":"Jie He, Jianxin Wang, Wei Liu, Xili Lu, Jingwei Lv, Lin Yang, Paul K. Chu, Chao Liu","doi":"10.1364/josaa.521774","DOIUrl":"https://doi.org/10.1364/josaa.521774","url":null,"abstract":"","PeriodicalId":501620,"journal":{"name":"Journal of the Optical Society of America A","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141119345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Distribution of colors and patterns in images is observed through cascades that adjust spatial resolution and dynamics. Cascades of colors reveal the emergent universal property that Fully Colored Images (FCIs) of natural scenes adhere to the debated continuous linear log-scale law (slope −2.00±0.01) (L1). Cascades of discrete 2×2 patterns are derived from pixel square reductions onto the seven unlabeled rotation-free textures (0000, 0001, 0011, 0012, 0101, 0102, 0123). They exhibit an unparalleled universal entropy maximum of 1.74±0.013 at some dynamics regardless of spatial scale (L2). Patterns also adhere to the Integral Fluctuation Theorem (1.00±0.01) (L3), pivotal in studies of chaotic systems. Images with fewer colors exhibit quadratic shift and bias from L1 and L3 but adhere to L2. Randomized Hilbert fractal FCIs better match the laws than basic-to-AI-based simulations. Those results are of interest in Neural Networks, out-of-equilibrium physics, and spectral imagery.
{"title":"Universal scale laws for colors and patterns in imagery","authors":"Rémi Michel, Mohamed Tamaazousti","doi":"10.1364/josaa.516720","DOIUrl":"https://doi.org/10.1364/josaa.516720","url":null,"abstract":"Distribution of colors and patterns in images is observed through cascades that adjust spatial resolution and dynamics. Cascades of colors reveal the emergent universal property that Fully Colored Images (FCIs) of natural scenes adhere to the debated continuous linear log-scale law (slope −2.00±0.01) (L1). Cascades of discrete 2×2 patterns are derived from pixel square reductions onto the seven unlabeled rotation-free textures (0000, 0001, 0011, 0012, 0101, 0102, 0123). They exhibit an unparalleled universal entropy maximum of 1.74±0.013 at some dynamics regardless of spatial scale (L2). Patterns also adhere to the Integral Fluctuation Theorem (1.00±0.01) (L3), pivotal in studies of chaotic systems. Images with fewer colors exhibit quadratic shift and bias from L1 and L3 but adhere to L2. Randomized Hilbert fractal FCIs better match the laws than basic-to-AI-based simulations. Those results are of interest in Neural Networks, out-of-equilibrium physics, and spectral imagery.","PeriodicalId":501620,"journal":{"name":"Journal of the Optical Society of America A","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141870136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Optical turbulence can cause substantial distortions in imaging over long horizontal paths. For Lambertian objects, these distortions are only seen where there is a gradient in the object’s radiance. It is possible to establish a relationship between the intensity variance of a turbulent image and the average image’s gradient squared. We test the validity of a linear relationship between these quantities using turbulent imaging data. We find that it performs reasonably well for weak and intermediate optical turbulence regimes, but that some discrepancies remain to be explained.
{"title":"Relationship between turbulent image variance and average image gradient","authors":"Guy Potvin","doi":"10.1364/josaa.516238","DOIUrl":"https://doi.org/10.1364/josaa.516238","url":null,"abstract":"Optical turbulence can cause substantial distortions in imaging over long horizontal paths. For Lambertian objects, these distortions are only seen where there is a gradient in the object’s radiance. It is possible to establish a relationship between the intensity variance of a turbulent image and the average image’s gradient squared. We test the validity of a linear relationship between these quantities using turbulent imaging data. We find that it performs reasonably well for weak and intermediate optical turbulence regimes, but that some discrepancies remain to be explained.","PeriodicalId":501620,"journal":{"name":"Journal of the Optical Society of America A","volume":"46 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140580737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jinping Cheng, Yin Feng, Hao Wu, Tao Wang, and Miaomiao Tang
The degree of paraxiality (DOP) of a radially polarized twisted multi-Gaussian Schell-model (RPT MGSM) beam is discussed, and the influence of the source parameters on its DOP is studied. It is shown that the parameters of the beam source, including the boundary characteristic, the beam waist width, the coherence width of the source correlation, and the twist factor, have a significant impact on the DOP of the RPT MGSM beam. To explain the behaviors of the DOP, the far-field divergence angle of this beam is also discussed.
{"title":"Degree of paraxiality of radially polarized twisted multi-Gaussian Schell-model beams","authors":"Jinping Cheng, Yin Feng, Hao Wu, Tao Wang, and Miaomiao Tang","doi":"10.1364/josaa.516407","DOIUrl":"https://doi.org/10.1364/josaa.516407","url":null,"abstract":"The degree of paraxiality (DOP) of a radially polarized twisted multi-Gaussian Schell-model (RPT MGSM) beam is discussed, and the influence of the source parameters on its DOP is studied. It is shown that the parameters of the beam source, including the boundary characteristic, the beam waist width, the coherence width of the source correlation, and the twist factor, have a significant impact on the DOP of the RPT MGSM beam. To explain the behaviors of the DOP, the far-field divergence angle of this beam is also discussed.","PeriodicalId":501620,"journal":{"name":"Journal of the Optical Society of America A","volume":"61 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140202417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of Surface Anchoring Energy on Liquid Crystal Optical Waveguide-Based Polarization Rotator","authors":"Zhenghui Zha","doi":"10.1364/josaa.520908","DOIUrl":"https://doi.org/10.1364/josaa.520908","url":null,"abstract":"","PeriodicalId":501620,"journal":{"name":"Journal of the Optical Society of America A","volume":"95 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140224098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study examined the diffraction of a pseudo nondiffracting Bessel beam by a perfect electromagnetic disk. The geometric optics beam waves were written from the geometry of the problem and related boundary conditions. The diffracted beam waves were derived by utilizing the relation between geometric optics and diffracted waves at the transition boundaries, considering the high frequency asymptotic expression of the scattered wave. The uniform scattered beam waves were expressed in terms of Fresnel functions with the uniform geometrical theory of the diffraction method. Thus, finite magnitudes were read at the transition boundaries. Finally, the obtained uniform expressions were investigated numerically for different groups of parameters.
{"title":"Diffraction of a pseudo nondiffracting Bessel beam by a circular perfect electromagnetic conductor disk","authors":"Husnu Deniz Basdemir","doi":"10.1364/josaa.516314","DOIUrl":"https://doi.org/10.1364/josaa.516314","url":null,"abstract":"This study examined the diffraction of a pseudo nondiffracting Bessel beam by a perfect electromagnetic disk. The geometric optics beam waves were written from the geometry of the problem and related boundary conditions. The diffracted beam waves were derived by utilizing the relation between geometric optics and diffracted waves at the transition boundaries, considering the high frequency asymptotic expression of the scattered wave. The uniform scattered beam waves were expressed in terms of Fresnel functions with the uniform geometrical theory of the diffraction method. Thus, finite magnitudes were read at the transition boundaries. Finally, the obtained uniform expressions were investigated numerically for different groups of parameters.","PeriodicalId":501620,"journal":{"name":"Journal of the Optical Society of America A","volume":"163 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140201982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chengyu Wu, Yanbin Tang, J. Shi, Cuicui Li, Wenli He, Gangyun Xu, Jian Wu, Xianping Wang
{"title":"Ultra-high order mode-assisted optical differentiator for edge detection with high tunability","authors":"Chengyu Wu, Yanbin Tang, J. Shi, Cuicui Li, Wenli He, Gangyun Xu, Jian Wu, Xianping Wang","doi":"10.1364/josaa.520871","DOIUrl":"https://doi.org/10.1364/josaa.520871","url":null,"abstract":"","PeriodicalId":501620,"journal":{"name":"Journal of the Optical Society of America A","volume":"4 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140222541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Israel Julián-Macías, Gabriel Martínez-Niconoff, Gilberto Silva-Ortigoza, and Carolina Rickenstorff-Parrao
In the first part of this work, we introduce a monochromatic solution to the scalar wave equation in free space, defined by a superposition of monochromatic nondiffracting half Bessel-lattice optical fields, which is determined by two scalar functions; one is defined on frequency space, and the other is a complete integral to the eikonal equation in free space. We obtain expressions for the geometrical wavefronts, the caustic region, and the Poynting vector. We highlight that this solution is stable under small perturbations because it is characterized by a caustic of the hyperbolic umbilical type. In the second part, we introduce the corresponding solution to the Maxwell equations in free space.
{"title":"Nonparaxial accelerating waves as a superposition of nondiffracting Bessel-lattice optical fields","authors":"Israel Julián-Macías, Gabriel Martínez-Niconoff, Gilberto Silva-Ortigoza, and Carolina Rickenstorff-Parrao","doi":"10.1364/josaa.518866","DOIUrl":"https://doi.org/10.1364/josaa.518866","url":null,"abstract":"In the first part of this work, we introduce a monochromatic solution to the scalar wave equation in free space, defined by a superposition of monochromatic nondiffracting half Bessel-lattice optical fields, which is determined by two scalar functions; one is defined on frequency space, and the other is a complete integral to the eikonal equation in free space. We obtain expressions for the geometrical wavefronts, the caustic region, and the Poynting vector. We highlight that this solution is stable under small perturbations because it is characterized by a caustic of the hyperbolic umbilical type. In the second part, we introduce the corresponding solution to the Maxwell equations in free space.","PeriodicalId":501620,"journal":{"name":"Journal of the Optical Society of America A","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140202033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shuaikang Fu, Ping Jiang, Yan Qin, Jianing Liu, and Huajun Yang
This study addresses the challenge of enhancing coupling efficiency between optical fibers and elliptical Gaussian beams emitted by semiconductor lasers, particularly in fiber communication systems. We introduce a method for fiber design utilizing the Joukowsky transformation to facilitate efficient mode transformation from elliptical to circular, thereby augmenting the coupling efficiency with both single-mode and multimode fibers. Theoretical analysis and numerical simulations demonstrate that the fiber with a structurally transitional core maintains high-efficiency mode transformation across various lengths, and its structure has been optimized accordingly. Additionally, our investigation reveals the designed fiber’s ability to preserve polarization states, which could have significant implications in precision optical applications. The proposed design offers an approach to improving performance in optical communication systems, especially in wavelength-division multiplexing (WDM) transmission systems and fiber lasers.
{"title":"Utilizing Joukowsky transformation in the design of optical fiber for elliptical-to-circular mode conversion","authors":"Shuaikang Fu, Ping Jiang, Yan Qin, Jianing Liu, and Huajun Yang","doi":"10.1364/josaa.515412","DOIUrl":"https://doi.org/10.1364/josaa.515412","url":null,"abstract":"This study addresses the challenge of enhancing coupling efficiency between optical fibers and elliptical Gaussian beams emitted by semiconductor lasers, particularly in fiber communication systems. We introduce a method for fiber design utilizing the Joukowsky transformation to facilitate efficient mode transformation from elliptical to circular, thereby augmenting the coupling efficiency with both single-mode and multimode fibers. Theoretical analysis and numerical simulations demonstrate that the fiber with a structurally transitional core maintains high-efficiency mode transformation across various lengths, and its structure has been optimized accordingly. Additionally, our investigation reveals the designed fiber’s ability to preserve polarization states, which could have significant implications in precision optical applications. The proposed design offers an approach to improving performance in optical communication systems, especially in wavelength-division multiplexing (WDM) transmission systems and fiber lasers.","PeriodicalId":501620,"journal":{"name":"Journal of the Optical Society of America A","volume":"163 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140202034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study proposes two types of composite structures based on gold nano circular and nano square rings on a gold thin film for plasmonic refractive index sensing. The finite-difference time-domain method was used for simulation and analysis. The nano square ring composite structure showed superior performance, with five surface plasmon resonance modes, and a peak sensitivity and figure of merit in a liquid environment of 1600 nm/RIU and 86RIU−1, respectively. The sensing performances of localized surface plasmon resonance modes of both structures are superior to those of the propagating surface plasmon resonance modes. The proposed composite structures can provide a reference for refractive index sensing and have broad application prospects in bio-chemistry.
{"title":"High-sensitivity refractive index sensor based on strong localized surface plasmon resonance","authors":"Hanwen Chen, Xiangxian Wang, Yizhen Chen, Xijun Rao, Huirong Zhu, Hua Yang, and Yunping Qi","doi":"10.1364/josaa.517964","DOIUrl":"https://doi.org/10.1364/josaa.517964","url":null,"abstract":"This study proposes two types of composite structures based on gold nano circular and nano square rings on a gold thin film for plasmonic refractive index sensing. The finite-difference time-domain method was used for simulation and analysis. The nano square ring composite structure showed superior performance, with five surface plasmon resonance modes, and a peak sensitivity and figure of merit in a liquid environment of 1600 nm/RIU and <span><span style=\"color: inherit;\"><span><span><span>86</span></span><span style=\"width: 0.278em; height: 0em;\"></span><span><span><span style=\"margin-right: 0.05em;\"><span>R</span><span>I</span><span>U</span></span><span style=\"vertical-align: 0.5em;\"><span>−</span><span>1</span></span></span></span></span></span><script type=\"math/tex\">{86};{{rm RIU}^{- 1}}</script></span>, respectively. The sensing performances of localized surface plasmon resonance modes of both structures are superior to those of the propagating surface plasmon resonance modes. The proposed composite structures can provide a reference for refractive index sensing and have broad application prospects in bio-chemistry.","PeriodicalId":501620,"journal":{"name":"Journal of the Optical Society of America A","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140154926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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