Vibrational dephasing times for benzene and carbon disulfide are measured using a custom single-beam Coherent Anti-stokes Raman Spectroscopy (CARS) setup. A femtosecond oscillator is used to pump a Polarization Maintaining All Normal Dispersion Photonic Crystal Fibre (PM-ANDi-PCF) to generate a broad band supercontinuum, covering a spectral region from 680 – 900 nm. The dispersion properties of the PM-ANDi-PCF ensures the supercontinuum is stable and there exists a fixed phase relationship between the spectral components of the supercontinuum. This enables its temporal compression using i2PIE, implemented using a liquid crystal spatial light modulator (SLM) in a 4f geometry. This SLM is also used to shape the pulse spectrally and temporally. With this setup we could demonstrate time-resolved CARS, measuring the vibrational relaxation times of a CS2/benzene mixture, and eliminate the non-resonant background completely. The main advantage of this setup is the fact that it is a single beam technique, eliminating the requirement for aligning the overlap of the pump and probe, both spatially and temporally, in the focal plane of the microscope. The strengths and limitations of the technique are highlighted and the route to time-resolved/background free vibrational microscopy is proposed.
{"title":"Novel time-resolved CARS implementation for application in microscopy","authors":"P. Neethling","doi":"10.1051/jeos/2023008","DOIUrl":"https://doi.org/10.1051/jeos/2023008","url":null,"abstract":"Vibrational dephasing times for benzene and carbon disulfide are measured using a custom single-beam Coherent Anti-stokes Raman Spectroscopy (CARS) setup. A femtosecond oscillator is used to pump a Polarization Maintaining All Normal Dispersion Photonic Crystal Fibre (PM-ANDi-PCF) to generate a broad band supercontinuum, covering a spectral region from 680 – 900 nm. The dispersion properties of the PM-ANDi-PCF ensures the supercontinuum is stable and there exists a fixed phase relationship between the spectral components of the supercontinuum. This enables its temporal compression using i2PIE, implemented using a liquid crystal spatial light modulator (SLM) in a 4f geometry. This SLM is also used to shape the pulse spectrally and temporally. With this setup we could demonstrate time-resolved CARS, measuring the vibrational relaxation times of a CS2/benzene mixture, and eliminate the non-resonant background completely. The main advantage of this setup is the fact that it is a single beam technique, eliminating the requirement for aligning the overlap of the pump and probe, both spatially and temporally, in the focal plane of the microscope. The strengths and limitations of the technique are highlighted and the route to time-resolved/background free vibrational microscopy is proposed.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47395108","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}
Alzahra A. Abd El-Moula, M. Raaif, F. El-Hossary, Mohamed Abo El-Kassem
In this study, CdO/Cu/CdO multilayers thin films were organized on glass substrates with different Cu intermetallic layer thickness engaging DC plasma magnetron sputtering. The optoelectronic properties and structural characteristics of the multilayers at various Cu intermetallic layer thicknesses which were varied from 4 to 16 nm were explored. The calculated band gap was reduced from 2.66 eV to 2.48 eV as the Cu intermetallic layer thickness increased from 4 to 16 nm. The refractive index and coefficient of extinction of CdO/Cu/CdO multilayers increased with increasing the Cu intermetallic layer thickness. The resistivity is reduced from 1.8×10−2 Ω.cm for CdO single layer to reach a value of 2.7×10−4 Ω.cm for CdO/Cu (16nm)/CdO multilayer. Further, the sheet resistance is decreased from 1000 to 13.8 /sq with the variation in Cu intermetallic layer thickness from 0 to 16 nm. CdO/Cu (4 nm)/CdO multilayer film recorded the best figure of merit (2.3x10-4 Ω−1). After sunlight illumination for the multilayers, the surface wettability was improved and the contact angle recorded lowest value of nearly 24 for CdO/Cu (8nm)/CdO and CdO/Cu (12nm)/CdO.
{"title":"DC pulsed plasma magnetron sputtering of CdO/Cu/CdO multilayers thin films for self-cleaning and optoelectronic applications","authors":"Alzahra A. Abd El-Moula, M. Raaif, F. El-Hossary, Mohamed Abo El-Kassem","doi":"10.1051/jeos/2023009","DOIUrl":"https://doi.org/10.1051/jeos/2023009","url":null,"abstract":"In this study, CdO/Cu/CdO multilayers thin films were organized on glass substrates with different Cu intermetallic layer thickness engaging DC plasma magnetron sputtering. The optoelectronic properties and structural characteristics of the multilayers at various Cu intermetallic layer thicknesses which were varied from 4 to 16 nm were explored. The calculated band gap was reduced from 2.66 eV to 2.48 eV as the Cu intermetallic layer thickness increased from 4 to 16 nm. The refractive index and coefficient of extinction of CdO/Cu/CdO multilayers increased with increasing the Cu intermetallic layer thickness. The resistivity is reduced from 1.8×10−2 Ω.cm for CdO single layer to reach a value of 2.7×10−4 Ω.cm for CdO/Cu (16nm)/CdO multilayer. Further, the sheet resistance is decreased from 1000 to 13.8 /sq with the variation in Cu intermetallic layer thickness from 0 to 16 nm. CdO/Cu (4 nm)/CdO multilayer film recorded the best figure of merit (2.3x10-4 Ω−1). After sunlight illumination for the multilayers, the surface wettability was improved and the contact angle recorded lowest value of nearly 24 for CdO/Cu (8nm)/CdO and CdO/Cu (12nm)/CdO.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49480098","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}
M. Schneckenburger, Sven Hoefler, R. Boerret, R. Almeida, Ines Braga
Robot polishing is increasingly used in the production of high-end glass work pieces such as astronomy mirrors, lithography lenses, laser gyroscopes or high-precision coordinate measuring machines. The quality of optical components such as lenses or mirrors can be described by shape errors and surface roughness. Whilst the trend towards sub nanometre level surfaces finishes and features progresses, matching both form and finish coherently in complex parts remains a major challenge. With larger or more precise optics, the influence of process instabilities on the quality of the optics to be polished has a greater impact. Vibrations at a polishing head have a negative influence on the polishing result. These vibrations are caused by bearing damage, motors and other excitations (e.g. gears, belts). The aim of this work is the determination of vibrations at a polishing head and their avoidance strategies. Different bearing conditions are considered: new and perfect bearing, a bearing that has been in contact with polish (rust) and a bearing with repeatable damage (groove milled on the running surface). It can be shown that the frequencies of bearings affect the polishing tool. Furthermore, reasons for and against vibrations in the process are discussed. For the case of vibrationless machining, avoidance strategies were presented.
{"title":"Monitoring and meaning of vibrations in robot polishing","authors":"M. Schneckenburger, Sven Hoefler, R. Boerret, R. Almeida, Ines Braga","doi":"10.1051/jeos/2023007","DOIUrl":"https://doi.org/10.1051/jeos/2023007","url":null,"abstract":"Robot polishing is increasingly used in the production of high-end glass work pieces such as astronomy mirrors, lithography lenses, laser gyroscopes or high-precision coordinate measuring machines. The quality of optical components such as lenses or mirrors can be described by shape errors and surface roughness. Whilst the trend towards sub nanometre level surfaces finishes and features progresses, matching both form and finish coherently in complex parts remains a major challenge. With larger or more precise optics, the influence of process instabilities on the quality of the optics to be polished has a greater impact. Vibrations at a polishing head have a negative influence on the polishing result. These vibrations are caused by bearing damage, motors and other excitations (e.g. gears, belts). The aim of this work is the determination of vibrations at a polishing head and their avoidance strategies. Different bearing conditions are considered: new and perfect bearing, a bearing that has been in contact with polish (rust) and a bearing with repeatable damage (groove milled on the running surface). It can be shown that the frequencies of bearings affect the polishing tool. Furthermore, reasons for and against vibrations in the process are discussed. For the case of vibrationless machining, avoidance strategies were presented.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49613921","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}
Transient dynamical-thermoelastic-optical system simulation is an important expansion of classical ray tracing through rigid, resting lenses because the operating performance of high-precision optical systems can be influenced by dynamical excitations or thermal gradients. In this paper an approach for an integrated optical system simulation using the coupling of elastic multibody system simulations, thermoelastic finite element analysis and gradient-index ray tracing is presented. Transient mechanical rigid body motions and elastic deformations, thermally induced refraction index changes, and thermal elastic deformations can be considered simultaneously in the ray tracing using the presented method. The calculation of the dynamical and thermal disturbances, the data transfer and coupling, and the gradient index ray tracing method are introduced. Finally, the approach is applied on a transient triplet lens optical system and some investigation results are shown.
{"title":"Transient Optical Simulation by Coupling Elastic Multibody Systems, Finite Elements, and Ray Tracing","authors":"L. Hahn, Fabian Matter, P. Eberhard","doi":"10.1051/jeos/2023006","DOIUrl":"https://doi.org/10.1051/jeos/2023006","url":null,"abstract":"Transient dynamical-thermoelastic-optical system simulation is an important expansion of classical ray tracing through rigid, resting lenses because the operating performance of high-precision optical systems can be influenced by dynamical excitations or thermal gradients. In this paper an approach for an integrated optical system simulation using the coupling of elastic multibody system simulations, thermoelastic finite element analysis and gradient-index ray tracing is presented. Transient mechanical rigid body motions and elastic deformations, thermally induced refraction index changes, and thermal elastic deformations can be considered simultaneously in the ray tracing using the presented method. The calculation of the dynamical and thermal disturbances, the data transfer and coupling, and the gradient index ray tracing method are introduced. Finally, the approach is applied on a transient triplet lens optical system and some investigation results are shown.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44713165","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}
This work presents a new technique based on modulating the IR absorbance of each element in a mixture in a chirped manner to reduce the effect of their partial spectral absorption overlap on the accuracy of determining their concentrations. This Chirped Spectral Modulation CSM algorithm can deal with mixtures containing unknown elements rather than the elements whose concentrations are aimed. This novel algorithm, when compared to existing pattern recognition techniques, makes it easy to analyze the constituents of a mixture with high accuracy in the presence of traces of unknown components. It is found that the new algorithm can detect the presence of gas pollutants such as sulfur dioxide, carbon monoxide, carbon dioxide, nitrogen dioxide in a sample containing many other unknown polluting elements. This new algorithm is tested on air samples composed of predetermined percentages of air constituents and the results of calculations are compared with those of Classical Least Squares CLS pattern recognition algorithm. The comparison showed that the new algorithm can detect down to very small traces of harmful gases such as NO2, and SO2, at least one order of magnitude less than those detected by the CLS approach. Finally, the new algorithm is used to examine collected air samples from an industrial zone, and in the middle and at the exit of a road tunnel in Riyadh area which showed that the percentages of sulfur dioxide, nitrogen dioxide, and carbon monoxide are well below the safe levels.
{"title":"Environmental Pollution Detection: A Novel Chirped Spectral Modulation Algorithm for a more Accurate Monitoring of Gas Pollutants in air","authors":"Mohamed Shalaby, F. Alorifi","doi":"10.1051/jeos/2023005","DOIUrl":"https://doi.org/10.1051/jeos/2023005","url":null,"abstract":"This work presents a new technique based on modulating the IR absorbance of each element in a mixture in a chirped manner to reduce the effect of their partial spectral absorption overlap on the accuracy of determining their concentrations. This Chirped Spectral Modulation CSM algorithm can deal with mixtures containing unknown elements rather than the elements whose concentrations are aimed. This novel algorithm, when compared to existing pattern recognition techniques, makes it easy to analyze the constituents of a mixture with high accuracy in the presence of traces of unknown components. It is found that the new algorithm can detect the presence of gas pollutants such as sulfur dioxide, carbon monoxide, carbon dioxide, nitrogen dioxide in a sample containing many other unknown polluting elements. This new algorithm is tested on air samples composed of predetermined percentages of air constituents and the results of calculations are compared with those of Classical Least Squares CLS pattern recognition algorithm. The comparison showed that the new algorithm can detect down to very small traces of harmful gases such as NO2, and SO2, at least one order of magnitude less than those detected by the CLS approach. Finally, the new algorithm is used to examine collected air samples from an industrial zone, and in the middle and at the exit of a road tunnel in Riyadh area which showed that the percentages of sulfur dioxide, nitrogen dioxide, and carbon monoxide are well below the safe levels.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41299653","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}
Space Debris Laser Ranging (DLR) is a technique to measure range to defunct satellites, rocket bodies or other space targets in orbits around Earth. The analysis on the probability shows that one of the reasons for the low success probability of DLR is the inaccurate orbital prediction of targets. Then it is proposed to use the Superconducting Nanowire Single-Photon Detector (SNSPD) running in automatic-recoverable range-gate-free mode, in which case, the effect of the accuracy of the target’s orbital prediction on the success probability of DLR is greatly reduced. In this way, 249 space debris were successfully detected and 532 passes of data were obtained. The smallest target detected was the space-debris (902) with an orbital altitude of about 1000 km and a Radar Cross Section (RCS) of 0.0446 m2. The farthest target detected was the space-debris (12445) with a large elliptical orbit and an RCS of 18.2505 m2, of which the range of the normal point (NPT) of the measured arc-segment on January 27, 2019 was 6260.805 km.
{"title":"Space Debris Laser Ranging with range-gate-free Superconducting Nanowire Single-Photon Detector","authors":"Haitao Zhang, Yuqiang Li, Zhulian Li, Xiao-ping Pi, Yongzhang Yang, Rufeng Tang","doi":"10.1051/jeos/2023002","DOIUrl":"https://doi.org/10.1051/jeos/2023002","url":null,"abstract":"Space Debris Laser Ranging (DLR) is a technique to measure range to defunct satellites, rocket bodies or other space targets in orbits around Earth. The analysis on the probability shows that one of the reasons for the low success probability of DLR is the inaccurate orbital prediction of targets. Then it is proposed to use the Superconducting Nanowire Single-Photon Detector (SNSPD) running in automatic-recoverable range-gate-free mode, in which case, the effect of the accuracy of the target’s orbital prediction on the success probability of DLR is greatly reduced. In this way, 249 space debris were successfully detected and 532 passes of data were obtained. The smallest target detected was the space-debris (902) with an orbital altitude of about 1000 km and a Radar Cross Section (RCS) of 0.0446 m2. The farthest target detected was the space-debris (12445) with a large elliptical orbit and an RCS of 18.2505 m2, of which the range of the normal point (NPT) of the measured arc-segment on January 27, 2019 was 6260.805 km.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45329034","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}
Extreme learning machines (ELMs) are a versatile machine learning (ML) algorithm that features as the main advantage the possibility of a seamless implementation with physical systems. Yet, despite the success of the physical implementations of ELMs, there is still a lack of fundamental understanding in regard to their optical implementations. In this context, this work makes use of an optical complex media and wavefront shaping techniques to implement a versatile optical ELM playground to gain a deeper insight into these machines. In particular, we present experimental evidences on the correlation between the effective dimensionality of the hidden space and its generalization capability, thus bringing the inner workings of optical ELMs under a new light and opening paths toward future technological implementations of similar principles.
{"title":"Exploring the hidden dimensions of an optical extreme learning machine","authors":"Duarte Silva","doi":"10.1051/jeos/2023001","DOIUrl":"https://doi.org/10.1051/jeos/2023001","url":null,"abstract":"Extreme learning machines (ELMs) are a versatile machine learning (ML) algorithm that features as the main advantage the possibility of a seamless implementation with physical systems. Yet, despite the success of the physical implementations of ELMs, there is still a lack of fundamental understanding in regard to their optical implementations. In this context, this work makes use of an optical complex media and wavefront shaping techniques to implement a versatile optical ELM playground to gain a deeper insight into these machines. In particular, we present experimental evidences on the correlation between the effective dimensionality of the hidden space and its generalization capability, thus bringing the inner workings of optical ELMs under a new light and opening paths toward future technological implementations of similar principles.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43035279","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}
Ali Abdel-Rahman Marouf, Fatima Awad, Yousef A. Alsabah, Mohammed U. Orsod
The focus of this study was to develop a method to demonstrate the feasibility of obtaining useful and high-value resources from Phoenix dactylifera residues and, to determine the physical and chemical properties of the ash of dates-palm-tree remains. Date-palm leaves and fiber samples were combusted for 50 s, using an Nd: YAG laser with 40 W output power. It was found, that combustion of agricultural waste could be completed in 30 seconds by laser while it required 1-2 minutes by microwave and at least 2 hours for conventional heating. The subjects of this treatment, the leaves and fiber samples, before and after combustion were investigated by X-ray diffraction (XRD) and Fourier transform infrared (FTIR). The XRD results of the palm-fiber after combustion reveal that the samples were crystallized with a rhombohedral phase of acetamide and hatrurite, orthorhombic finite, and Ca4Si2O6 (CO3)(OH)2, and a monoclinic phase of ikaite properties. The XRD patterns of palm-leaf after combustion reveal that the samples were crystallized with orthorhombic hillebrandite, rhombohedral acetamide, and the monoclinic phase of each karpatite, morganite, and howlite. Finally, the FTIR exhibited several absorbance peaks, assigned to silica.
{"title":"An Attempt to Apply Laser Combustion to Palm Waste","authors":"Ali Abdel-Rahman Marouf, Fatima Awad, Yousef A. Alsabah, Mohammed U. Orsod","doi":"10.1051/jeos/2023003","DOIUrl":"https://doi.org/10.1051/jeos/2023003","url":null,"abstract":"The focus of this study was to develop a method to demonstrate the feasibility of obtaining useful and high-value resources from Phoenix dactylifera residues and, to determine the physical and chemical properties of the ash of dates-palm-tree remains. Date-palm leaves and fiber samples were combusted for 50 s, using an Nd: YAG laser with 40 W output power. It was found, that combustion of agricultural waste could be completed in 30 seconds by laser while it required 1-2 minutes by microwave and at least 2 hours for conventional heating. The subjects of this treatment, the leaves and fiber samples, before and after combustion were investigated by X-ray diffraction (XRD) and Fourier transform infrared (FTIR). The XRD results of the palm-fiber after combustion reveal that the samples were crystallized with a rhombohedral phase of acetamide and hatrurite, orthorhombic finite, and Ca4Si2O6 (CO3)(OH)2, and a monoclinic phase of ikaite properties. The XRD patterns of palm-leaf after combustion reveal that the samples were crystallized with orthorhombic hillebrandite, rhombohedral acetamide, and the monoclinic phase of each karpatite, morganite, and howlite. Finally, the FTIR exhibited several absorbance peaks, assigned to silica.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49307602","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}
M. Lee, J. Cholet, A. Delboulbé, R. Guillemet, B. Loiseaux, P. Garabédian, T. Flügel-Paul, T. Benkenstein, S. Sadlowski, N. Tetaz, R. Windpassinger, A. Baselga Mateo
We report on subwavelength reflective gratings for hyperspectral applications operating in a very large spectral band (340 nm -1040 nm). Our study concerns a blazed-binary grating having a period of 30µm and composed of 2D subwavelength structures with size in between 120 nm and 350 nm. We demonstrate the manufacturing of the gratings on 3” wafers by two lithography technologies (e-beam and nanoimprint) followed by classical dry etching process. Optical measurements show that the subwavelength grating approach enables a broadband efficiency, polarization behaviour and wavefront quality improvement with respect to the requirements for the next generation of spectro-imagers for Earth observation missions. An outlook towards spherical substrate based on nanoimprint lithography is also reported with the results of mixed features replication (holes and pillars in the range of 160 nm to 330 nm) on a 540 mm concave which demonstrate uniformity and accuracy capabilities over 3” surface.
{"title":"Wide band UV/Vis/NIR blazed-binary reflective gratings for spectro-imagers: two lithographic technologies investigation","authors":"M. Lee, J. Cholet, A. Delboulbé, R. Guillemet, B. Loiseaux, P. Garabédian, T. Flügel-Paul, T. Benkenstein, S. Sadlowski, N. Tetaz, R. Windpassinger, A. Baselga Mateo","doi":"10.1051/jeos/2023004","DOIUrl":"https://doi.org/10.1051/jeos/2023004","url":null,"abstract":"We report on subwavelength reflective gratings for hyperspectral applications operating in a very large spectral band (340 nm -1040 nm). Our study concerns a blazed-binary grating having a period of 30µm and composed of 2D subwavelength structures with size in between 120 nm and 350 nm. We demonstrate the manufacturing of the gratings on 3” wafers by two lithography technologies (e-beam and nanoimprint) followed by classical dry etching process. Optical measurements show that the subwavelength grating approach enables a broadband efficiency, polarization behaviour and wavefront quality improvement with respect to the requirements for the next generation of spectro-imagers for Earth observation missions. An outlook towards spherical substrate based on nanoimprint lithography is also reported with the results of mixed features replication (holes and pillars in the range of 160 nm to 330 nm) on a 540 mm concave which demonstrate uniformity and accuracy capabilities over 3” surface.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46377704","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}
T. Villedieu, L. Lablonde, H. Boiron, Adrien Steib, G. Mélin, T. Robin, B. Cadier, M. Rattier, H. Lefèvre
A recent JEOS-RP publication proposed Comments about Dispersion of Light Waves, and we present here complementary comments for birefringence dispersion in polarization-maintaining (PM) fibers, and for its measurement techniques based on channeled spectrum analysis. We start by a study of early seminal papers, and we propose additional explanations to get a simpler understanding of the subject. A geometrical construction is described to relate phase birefringence to group birefringence, and it is applied to the measurement of several kinds of PM fibers using stress-induced photo-elasticity, or shape birefringence. These measurements confirm clearly that the difference between group birefringence and phase birefringence is limited to 15–20% in stress-induced PM fibers (bow-tie, panda, or tiger-eye), but that it can get up to a 3-fold factor with an elliptical-core (E-core) fiber. There are also surprising results with solid-core micro-structured PM fibers, that are based on shape birefringence, as E-core fibers.
{"title":"Comments about birefringence dispersion, with group and phase birefringence measurements in polarization-maintaining fibers","authors":"T. Villedieu, L. Lablonde, H. Boiron, Adrien Steib, G. Mélin, T. Robin, B. Cadier, M. Rattier, H. Lefèvre","doi":"10.1051/jeos/2022014","DOIUrl":"https://doi.org/10.1051/jeos/2022014","url":null,"abstract":"A recent JEOS-RP publication proposed Comments about Dispersion of Light Waves, and we present here complementary comments for birefringence dispersion in polarization-maintaining (PM) fibers, and for its measurement techniques based on channeled spectrum analysis. We start by a study of early seminal papers, and we propose additional explanations to get a simpler understanding of the subject. A geometrical construction is described to relate phase birefringence to group birefringence, and it is applied to the measurement of several kinds of PM fibers using stress-induced photo-elasticity, or shape birefringence. These measurements confirm clearly that the difference between group birefringence and phase birefringence is limited to 15–20% in stress-induced PM fibers (bow-tie, panda, or tiger-eye), but that it can get up to a 3-fold factor with an elliptical-core (E-core) fiber. There are also surprising results with solid-core micro-structured PM fibers, that are based on shape birefringence, as E-core fibers.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57899111","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}
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