A topology optimization method is presented and applied to a blazed diffraction grating in reflection under conical incidence. This type of grating is meant to disperse the incident light on one particular diffraction order, and this property is fundamental in spectroscopy. Conventionally, a blazed metallic grating is made of a sawtooth profile designed to work with the ±1st diffraction order in reflection. In this paper, we question this intuitive triangular pattern and look for optimal opto-geometric characteristics using topology optimization based on finite element modelling of Maxwell’s equations. In practical contexts, the grating geometry is mono-periodic, but it is enlightened by a 3D plane wave with a wave vector outside of the plane of invariance. Consequently, this study deals with the resolution of direct and inverse problems using the finite element method in this intermediate state between 2D and 3D: the so-called conical incidence. A multi-wavelength objective is used in order to obtain a broadband blazed effect. Finally, several numerical experiments are detailed. Our numerical results show that it is possible to reach a 98% diffraction efficiency on the −1st diffraction order if the optimization is performed on a single wavelength, and that the reflection integrated over the [400,1500] nm wavelength range can be 29% higher in absolute terms, 56% in relative terms, than that of the sawtooth blazed grating when using a multi-wavelength optimization criterion (from 52% to 81%).
{"title":"Topology optimization of blazed gratings under conical incidence","authors":"Simon Ans, Frédéric Zamkotsian, Guillaume Demésy","doi":"10.1364/josaa.524289","DOIUrl":"https://doi.org/10.1364/josaa.524289","url":null,"abstract":"A topology optimization method is presented and applied to a blazed diffraction grating in reflection under conical incidence. This type of grating is meant to disperse the incident light on one particular diffraction order, and this property is fundamental in spectroscopy. Conventionally, a blazed metallic grating is made of a sawtooth profile designed to work with the ±1st diffraction order in reflection. In this paper, we question this intuitive triangular pattern and look for optimal opto-geometric characteristics using topology optimization based on finite element modelling of Maxwell’s equations. In practical contexts, the grating geometry is mono-periodic, but it is enlightened by a 3D plane wave with a wave vector outside of the plane of invariance. Consequently, this study deals with the resolution of direct and inverse problems using the finite element method in this intermediate state between 2D and 3D: the so-called conical incidence. A multi-wavelength objective is used in order to obtain a broadband blazed effect. Finally, several numerical experiments are detailed. Our numerical results show that it is possible to reach a 98% diffraction efficiency on the −1st diffraction order if the optimization is performed on a single wavelength, and that the reflection integrated over the [400,1500] nm wavelength range can be 29% higher in absolute terms, 56% in relative terms, than that of the sawtooth blazed grating when using a multi-wavelength optimization criterion (from 52% to 81%).","PeriodicalId":501620,"journal":{"name":"Journal of the Optical Society of America A","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141870029","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}
Radially polarized light beams present very interesting and useful behavior for creating small intensity spots when tightly focused, and manipulating nanostructures or charged particles via their longitudinal field. The modeling of the propagation of such vector beams, however, is almost always done using the lowest-order fundamental radially polarized beam or a single higher-order mode due to the complexity of vector diffraction theory. We show how a flat-top radially polarized beam, relevant for high-power lasers, can be modeled analytically using a sum of higher-order beams, describe a number of interesting qualities of such beams, and compare to numerically solved integral descriptions.
{"title":"Modeling the focusing of a radially polarized laser beam with an initially flat-top intensity profile","authors":"Spencer W. Jolly","doi":"10.1364/josaa.528336","DOIUrl":"https://doi.org/10.1364/josaa.528336","url":null,"abstract":"Radially polarized light beams present very interesting and useful behavior for creating small intensity spots when tightly focused, and manipulating nanostructures or charged particles via their longitudinal field. The modeling of the propagation of such vector beams, however, is almost always done using the lowest-order fundamental radially polarized beam or a single higher-order mode due to the complexity of vector diffraction theory. We show how a flat-top radially polarized beam, relevant for high-power lasers, can be modeled analytically using a sum of higher-order beams, describe a number of interesting qualities of such beams, and compare to numerically solved integral descriptions.","PeriodicalId":501620,"journal":{"name":"Journal of the Optical Society of America A","volume":"77 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141870030","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}
Rahul Kumar, Praveen Kumar, Naveen K. Nishchal, Ayman Alfalou
Optical vortices carrying orbital angular momentum have drawn much attention because they provide high-dimensional encoding. Employing an array of optical vortices, we demonstrate an authentication verification system. For security authentication, an exclusive-OR logic operation has been implemented employing a light beam consisting of an array of vortices. A liquid crystal spatial light modulator has been used to generate orthogonal states of optical vortices. The proposed technique can provide a secure method of authentication with straightforward implementation. We have presented simulation and experimental results to verify the proposed scheme.
{"title":"Image authentication with exclusive-OR operated optical vortices","authors":"Rahul Kumar, Praveen Kumar, Naveen K. Nishchal, Ayman Alfalou","doi":"10.1364/josaa.527399","DOIUrl":"https://doi.org/10.1364/josaa.527399","url":null,"abstract":"Optical vortices carrying orbital angular momentum have drawn much attention because they provide high-dimensional encoding. Employing an array of optical vortices, we demonstrate an authentication verification system. For security authentication, an exclusive-OR logic operation has been implemented employing a light beam consisting of an array of vortices. A liquid crystal spatial light modulator has been used to generate orthogonal states of optical vortices. The proposed technique can provide a secure method of authentication with straightforward implementation. We have presented simulation and experimental results to verify the proposed scheme.","PeriodicalId":501620,"journal":{"name":"Journal of the Optical Society of America A","volume":"109 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141870052","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}
Atmospheric refraction modifies the apparent position of objects in the sky, and also produces a progressive lateral shift of the light rays received from these objects; in the case of a spherically symmetric atmosphere, for the first time, this shift has been numerically studied in 2022, and different analytical estimators have been compared (by Labriji et al.) for the total shift. This topic is important for the reconstruction of meteor trajectories, for the analysis of wavefront sensing in adaptative optics, etc. Always in the case of a spherically symmetric atmosphere, we show two other analytical methods to study this lateral shift, and to be able to estimate it analytically in the difficult case when the celestial object is seen near the astronomical horizon. One of these methods allows us to deduce an estimator, not only of the total shift, but also of the shift of any point of the ray. We compare properties of the total lateral shift and of the refraction angle, and also the chromatism of the total lateral shift to the chromatism of the air refractivity, for rays coming from an object seen either high enough above the astronomical horizon, or on it. In this latter case, our first method shows departures from proportionality between the chromatisms of the air refractivity, of the astronomical refraction angle, and, even more, of the total lateral shift.
{"title":"Study of the lateral shift due to atmospheric refraction: alternative analytical methods, and new results","authors":"L. Dettwiller","doi":"10.1364/josaa.522962","DOIUrl":"https://doi.org/10.1364/josaa.522962","url":null,"abstract":"Atmospheric refraction modifies the apparent position of objects in the sky, and also produces a progressive lateral shift of the light rays received from these objects; in the case of a spherically symmetric atmosphere, for the first time, this shift has been numerically studied in 2022, and different analytical estimators have been compared (by Labriji <jats:italic toggle=\"yes\">et al.</jats:italic>) for the total shift. This topic is important for the reconstruction of meteor trajectories, for the analysis of wavefront sensing in adaptative optics, etc. Always in the case of a spherically symmetric atmosphere, we show two other analytical methods to study this lateral shift, and to be able to estimate it analytically in the difficult case when the celestial object is seen near the astronomical horizon. One of these methods allows us to deduce an estimator, not only of the total shift, but also of the shift of any point of the ray. We compare properties of the total lateral shift and of the refraction angle, and also the chromatism of the total lateral shift to the chromatism of the air refractivity, for rays coming from an object seen either high enough above the astronomical horizon, or on it. In this latter case, our first method shows departures from proportionality between the chromatisms of the air refractivity, of the astronomical refraction angle, and, even more, of the total lateral shift.","PeriodicalId":501620,"journal":{"name":"Journal of the Optical Society of America A","volume":"67 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141870051","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}
A complete description of the polarization properties of a random, stationary, generally three-dimensional (3D) optical field in a point is provided by the 3×3 polarization matrix. We show that its nine degrees of freedom can be represented by nine independent and decoupled parameters with simple and significant physical meanings. These cover the three orientation angles determining the intrinsic reference frame with respect to an arbitrary one, the three principal intensities representing the strengths of the components of the electric field along the respective intrinsic reference axes, and a real-valued vector, which we term metaspin, whose three components are given by the intrinsic correlations of the field components. Consequently, any given polarization state has an associated intensity-isotropic state, called the metaspin state, whose spin vector is fully determined by the metaspin vector. We also show that the concept of metaspin provides an illustrative synthesis procedure for 3D polarization states. The results can straightforwardly be applied to any 3×3 density matrix.
{"title":"Information structure of a polarization state: the concept of metaspin","authors":"J. J. Gil, A. Norrman, A. T. Friberg, T. Setälä","doi":"10.1364/josaa.521863","DOIUrl":"https://doi.org/10.1364/josaa.521863","url":null,"abstract":"A complete description of the polarization properties of a random, stationary, generally three-dimensional (3D) optical field in a point is provided by the 3×3 polarization matrix. We show that its nine degrees of freedom can be represented by nine independent and decoupled parameters with simple and significant physical meanings. These cover the three orientation angles determining the intrinsic reference frame with respect to an arbitrary one, the three principal intensities representing the strengths of the components of the electric field along the respective intrinsic reference axes, and a real-valued vector, which we term metaspin, whose three components are given by the intrinsic correlations of the field components. Consequently, any given polarization state has an associated intensity-isotropic state, called the metaspin state, whose spin vector is fully determined by the metaspin vector. We also show that the concept of metaspin provides an illustrative synthesis procedure for 3D polarization states. The results can straightforwardly be applied to any 3×3 density matrix.","PeriodicalId":501620,"journal":{"name":"Journal of the Optical Society of America A","volume":"213 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141870053","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}
In the pinhole point diffraction interferometer (PPDI), proper alignment between the reflection spot of the tested component and the pinhole is critical to obtain accurate interferograms. At present, adjusting for tilt error requires manual manipulation, and defocus error cannot be corrected. These limitations impede the instrumentation process of PPDI. To address this issue, the proposed tested mirror alignment system utilizes diffraction theory to analyze the mathematical error caused by the misalignment of the tested mirror’s reflected beam and pinhole. An alignment system based on machine vision was designed according to specific requirements. This system incorporates a CCD camera with a zoom lens, the classic PPDI with a pinhole substrate containing a lithography-made mark, and a 3-DOF stepper motor adjusting frame to mount the tested mirror. Additionally, image processing algorithms and step motor driving programs were applied to achieve precise alignment. The system implementation and experimental results indicated that the tilt errors are well-controlled, achieving the defocus error modification, making the interferogram acquisition process more convenient. From the results, this system offers desirable precision and efficiency for PPDI’s tested mirror alignment.
{"title":"Tested mirror precision alignment system using a pinhole point diffraction interferometer based on machine vision","authors":"Jiasheng Lu, Bing Li, Zhuo Zhao, Leqi Geng","doi":"10.1364/josaa.523113","DOIUrl":"https://doi.org/10.1364/josaa.523113","url":null,"abstract":"In the pinhole point diffraction interferometer (PPDI), proper alignment between the reflection spot of the tested component and the pinhole is critical to obtain accurate interferograms. At present, adjusting for tilt error requires manual manipulation, and defocus error cannot be corrected. These limitations impede the instrumentation process of PPDI. To address this issue, the proposed tested mirror alignment system utilizes diffraction theory to analyze the mathematical error caused by the misalignment of the tested mirror’s reflected beam and pinhole. An alignment system based on machine vision was designed according to specific requirements. This system incorporates a CCD camera with a zoom lens, the classic PPDI with a pinhole substrate containing a lithography-made mark, and a 3-DOF stepper motor adjusting frame to mount the tested mirror. Additionally, image processing algorithms and step motor driving programs were applied to achieve precise alignment. The system implementation and experimental results indicated that the tilt errors are well-controlled, achieving the defocus error modification, making the interferogram acquisition process more convenient. From the results, this system offers desirable precision and efficiency for PPDI’s tested mirror alignment.","PeriodicalId":501620,"journal":{"name":"Journal of the Optical Society of America A","volume":"50 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141870054","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}
Gordon Wells, YiChen Wu, Maik Locher, Johannes Courtial
{"title":"Geometric construction of relativistic and non-relativistic distortion","authors":"Gordon Wells, YiChen Wu, Maik Locher, Johannes Courtial","doi":"10.1364/josaa.524591","DOIUrl":"https://doi.org/10.1364/josaa.524591","url":null,"abstract":"","PeriodicalId":501620,"journal":{"name":"Journal of the Optical Society of America A","volume":"88 24","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141101011","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":"Innovative Methodology for Non-Invasive Spatial Mapping of Gold Nanoparticle Distribution in Tissues: Potential Applications in Biomedical Imaging and Therapy","authors":"Ana Mendes, Adamo Monte, Rolf Saager","doi":"10.1364/josaa.523717","DOIUrl":"https://doi.org/10.1364/josaa.523717","url":null,"abstract":"","PeriodicalId":501620,"journal":{"name":"Journal of the Optical Society of America A","volume":"35 18","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141113574","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}
Svetlana Avramov-Zamurovic, Y. Ata, Andreas Muschinski, Dario Perez, Melissa Beason, Jeremy Bos
{"title":"PROPAGATION THROUGH AND CHARACTERIZATION OF ATMOSPHERIC AND OCEANIC PHENOMENA (PCAOP): INTRODUCTION TO THE FEATURE ISSUE","authors":"Svetlana Avramov-Zamurovic, Y. Ata, Andreas Muschinski, Dario Perez, Melissa Beason, Jeremy Bos","doi":"10.1364/josaa.530878","DOIUrl":"https://doi.org/10.1364/josaa.530878","url":null,"abstract":"","PeriodicalId":501620,"journal":{"name":"Journal of the Optical Society of America A","volume":"107 19","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141115923","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}
Qian Li, Zhixiang Zhang, Yixuan Li, Xiaoling Ji, Xiaoqing Li
{"title":"Analytical study on the upward laser beam propagation in the turbulent atmosphere","authors":"Qian Li, Zhixiang Zhang, Yixuan Li, Xiaoling Ji, Xiaoqing Li","doi":"10.1364/josaa.521344","DOIUrl":"https://doi.org/10.1364/josaa.521344","url":null,"abstract":"","PeriodicalId":501620,"journal":{"name":"Journal of the Optical Society of America A","volume":"83 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141114005","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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