{"title":"Method for assessing the impact of residual roughness after corneal ablation simulated as random and filtered noise in polychromatic vision","authors":"Shwetabh Verma","doi":"10.1051/jeos/2023013","DOIUrl":"https://doi.org/10.1051/jeos/2023013","url":null,"abstract":"Purpose: Despite theoretical models for achieving laser-based ablation smoothness, methods do not yet exist for assessing the impact of residual roughness after corneal ablation, on retinal polychromatic vision. We developed a method and performed an exploratory study to qualitatively and quantitatively analyze the impact of varying degree of corneal roughness simulated through white and filtered noise, on the retinal image.\u0000\u0000Methods: A preliminary version of the Indiana Retinal Image Simulator (IRIS) (J Opt SocAm A Opt Image SciVis. 2008 Oct;25(10):2395-407) was used to simulate the polychromatic retinal image. Using patient-specific Zernike coefficients and pupil diameter, the impact of different levels of chromatic aberrations was calculated. Corneal roughness was modeled via both random and filtered noise (Biomed. Opt. Express 4, 220-229 (2013)), using distinct pre-calculated higher order Zernike coefficient terms. The outcome measures for the simulation were simulated retinal image, Strehl Ratio and Visual Strehl Ratio computed in frequency domain (VSOTF). The impact of varying degree of roughness (with and without refractive error), spatial frequency of the roughness, and pupil dilation was analyzed on these outcome measures. Standard simulation settings were pupil size = 6mm, Defocus Z[2,0] = 2 μm (-1.54D), and Spherical Aberrations Z[4,0] = 0.15 μm. The signal included the 2-4th Zernike orders, while noise used 7-8th Zernike orders. Noise was scaled to predetermined RMS values. All the terms in 5th and 6th Zernike order were set to 0, to avoid overlapping of signal and noise. \u0000\u0000Results: In case of a constant roughness term, reducing the pupil size resulted in improved outcome measures and simulated retinal image (Strehl = 0.005 for pupil size = 6mm to Strehl = 0.06 for pupil size = 3mm). The calculated image quality metrics deteriorated dramatically with increasing roughness (Strehl = 0. 3 for no noise; Strehl = 0.03 for random noise of 0.25µm at 6mm diameter; Strehl = 0.005 for random noise of 0.65µm at 6mm diameter). Clear distinction was observed in outcome measures for corneal roughness simulated as random noise compared to filtered noise, further influenced by the spatial frequency of filtered noise.\u0000\u0000Conclusion: The proposed method enables quantifying the impact of residual roughness in corneal ablation processes at relatively low cost. Since normally laser ablation is an integral process divided on a defined grid, the impact of spatially characterized noise represents a more realistic simulation condition. This method can help comparing different refractive laser platforms in terms of their associated roughness in ablation, indirectly improving the quality of results after Laser vision correction surgery.\u0000","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45440575","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}
{"title":"Scalable sub-cycle pulse generation by soliton self-compression in hollow capillary fibers with a decreasing pressure gradient","authors":"Marina Fernández Galán","doi":"10.1051/jeos/2023011","DOIUrl":"https://doi.org/10.1051/jeos/2023011","url":null,"abstract":"Advances in the generation of the shortest optical laser pulses down to the sub-cycle regime promise to break new ground in ultrafast science. In this work, we theoretically demonstrate the potential scaling capabilities of soliton self-compression in hollow capillary fibers with a decreasing pressure gradient to generate near-infrared sub-cycle pulses in very different dispersion and nonlinearity landscapes. Independently of input pulse, gas and fiber choices, we present a simple and general route to find the optimal self-compression parameters which result in high-quality pulses. The use of a decreasing pressure gradient naturally favors the self-compression process, resulting in shorter and cleaner sub-cycle pulses, and an improvement in the robustness of the setup when compared to the traditional constant pressure approach.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47776922","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}
{"title":"Sorting microplastics from other materials in water samples by ultra-high-definition imaging","authors":"M. Roussey","doi":"10.1051/jeos/2023010","DOIUrl":"https://doi.org/10.1051/jeos/2023010","url":null,"abstract":"In this study a commercial particle analyzer was used to image and help sorting microplastic particles (MPs) dispersed in filtrated and de-aerated tap water. The device provides a relatively easy and fast procedure for obtaining ultra-high-definition imaging, allowing the determination of shape, size, and number of 2D-projections of solid particles. The image analysis revealed clear differences among the studied different MPs originating from the grinding of five common grades of plastic sheets as they affect the image rendering differently, principally due to the light scattering either at the surface or in the volume of the microplastics. The high-quality imaging of the device also allows the discrimination of the microplastics from air bubbles with well-defined spherical shapes as well as to obtain an estimate of the size of MPs in a snapshot. We associate the differences among the shapes of the identified MPs in this study depending on the plastic type with known physical properties, such as brittleness, crystallinity, or softness. Furthermore, as a novel method we exploit a parameter based on the light intensity map from moving particles in cuvette flow to sort MPs from other particles, such as, wood fiber, human hair, and air bubbles. Using the light intensity map, which is related to the plastic-water refractive index ratio, the presence of microplastics in water can be revealed among other particles, but not their specific plastic type.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48754023","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}
{"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":" ","pages":""},"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
{"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":" ","pages":""},"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
{"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":" ","pages":""},"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}
{"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":" ","pages":""},"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}
{"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":"20 1","pages":""},"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}
{"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":" ","pages":""},"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}
{"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":" ","pages":""},"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}