The need for remote teaching tools in all education levels has experienced a big increase due to COVID-19 pandemic. Laboratory practical sessions have not been an exception, and many online and offline tools have been made available to respond to the lockdown of teaching facilities. This paper presents a software testbed named OPTILAB for teaching diffraction experiments to engineering students. The software simulates classical diffraction apertures (single slit, double slit, circular slit) under a wide variety of conditions. Explanation about the Physics behind the diffraction phenomenon is also included in OPTILAB to increase the students’ self-learning experience. Originally conceived as a complement to on-site teaching, due to COVID-19 pandemic OPTILAB has been adopted as the basic tool to build a brand-new, virtual laboratory session about diffraction in Physics III course (biomedical engineering) at Carlos III University of Madrid. Results obtained by the students taking this virtual lab during Fall 2020 are presented and discussed.
{"title":"Diffraction Testbed for Use in Remote Teaching","authors":"Javier Gamo","doi":"10.3390/opt2040023","DOIUrl":"https://doi.org/10.3390/opt2040023","url":null,"abstract":"The need for remote teaching tools in all education levels has experienced a big increase due to COVID-19 pandemic. Laboratory practical sessions have not been an exception, and many online and offline tools have been made available to respond to the lockdown of teaching facilities. This paper presents a software testbed named OPTILAB for teaching diffraction experiments to engineering students. The software simulates classical diffraction apertures (single slit, double slit, circular slit) under a wide variety of conditions. Explanation about the Physics behind the diffraction phenomenon is also included in OPTILAB to increase the students’ self-learning experience. Originally conceived as a complement to on-site teaching, due to COVID-19 pandemic OPTILAB has been adopted as the basic tool to build a brand-new, virtual laboratory session about diffraction in Physics III course (biomedical engineering) at Carlos III University of Madrid. Results obtained by the students taking this virtual lab during Fall 2020 are presented and discussed.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85024104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
We theoretically analyze the case of noisy Quantum walks (QWs) by introducing four qubit decoherence models into the coin degree of freedom of linear and cyclic QWs. These models include flipping channels (bit flip, phase flip and bit-phase flip), depolarizing channel, phase damping channel and generalized amplitude damping channel. Explicit expressions for the probability distribution of QWs on a line and on a cyclic path are derived under localized and delocalized initial states. We show that QWs which begin from a delocalized state generate mixture probability distributions, which could give rise to useful algorithmic applications related to data encoding schemes. Specifically, we show how the combination of delocalzed initial states and decoherence can be used for computing the binomial transform of a given set of numbers. However, the sensitivity of QWs to noisy environments may negatively affect various other applications based on QWs.
{"title":"Analysis of Decoherence in Linear and Cyclic Quantum Walks","authors":"M. Jayakody, A. Nanayakkara, E. Cohen","doi":"10.3390/opt2040022","DOIUrl":"https://doi.org/10.3390/opt2040022","url":null,"abstract":"We theoretically analyze the case of noisy Quantum walks (QWs) by introducing four qubit decoherence models into the coin degree of freedom of linear and cyclic QWs. These models include flipping channels (bit flip, phase flip and bit-phase flip), depolarizing channel, phase damping channel and generalized amplitude damping channel. Explicit expressions for the probability distribution of QWs on a line and on a cyclic path are derived under localized and delocalized initial states. We show that QWs which begin from a delocalized state generate mixture probability distributions, which could give rise to useful algorithmic applications related to data encoding schemes. Specifically, we show how the combination of delocalzed initial states and decoherence can be used for computing the binomial transform of a given set of numbers. However, the sensitivity of QWs to noisy environments may negatively affect various other applications based on QWs.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":"128 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81821329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
The idea of utilizing game elements in non-gaming situations has sparked a lot of attention in recent years, especially in topics such as education and training. Game-based techniques appear to be an increasing trend in a wide range of learning areas, including health, social policy, and engineering, among others, not only in primary school but also in higher formal education. Using this methodology, the learning process becomes more stimulating while also reaching a competitive level in some circumstances. In the present work, the authors propose a new gamification strategy based on an escape-room in which all the puzzles to be passed are related to the area of optics and photonics and use readily available or low-cost equipment. The major field of application of this novel teaching strategy will be the practical section of a course, that is usually carried out in a laboratory, and will be aimed at both undergraduate and master’s degree students. A coevaluation method is also proposed where the rest of the students will provide valuable feedback to each one of their colleagues and to the instructor.
{"title":"Gamification for Photonics Students: Labescape","authors":"R. Pérez-Herrera, S. Tainta, C. Elosúa","doi":"10.3390/opt2040021","DOIUrl":"https://doi.org/10.3390/opt2040021","url":null,"abstract":"The idea of utilizing game elements in non-gaming situations has sparked a lot of attention in recent years, especially in topics such as education and training. Game-based techniques appear to be an increasing trend in a wide range of learning areas, including health, social policy, and engineering, among others, not only in primary school but also in higher formal education. Using this methodology, the learning process becomes more stimulating while also reaching a competitive level in some circumstances. In the present work, the authors propose a new gamification strategy based on an escape-room in which all the puzzles to be passed are related to the area of optics and photonics and use readily available or low-cost equipment. The major field of application of this novel teaching strategy will be the practical section of a course, that is usually carried out in a laboratory, and will be aimed at both undergraduate and master’s degree students. A coevaluation method is also proposed where the rest of the students will provide valuable feedback to each one of their colleagues and to the instructor.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87623701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Pub Date : 2021-10-05DOI: 10.11648/J.OPTICS.20211002.11
Mahasin Mohamed Dafaa Allah Banaga, A. Awadelgied, N. A. Muslet, N. Osman
Vegetable edible oils provide high nutritional and health value in the Sudanese diet. It is also used in the pharmaceutical industry and an essential ingredient in cosmetics. This paper reviews the use of Raman spectroscopy for the analysis, quality and characterization of edible oils, including six types of oils (corn, extra virgin olive, sunflower, factory sesame, presses sesame, and peanut) purchased from local Sudanese stores. The results showed that the spectra of edible oils are similar, but they show some differences that, despite their smallness, allow them to be distinguished from each other. Divide the spectrum into the fingerprint region. The range ranges between (600 and 1800) cm-1 the silent region", this spectral region is (1800 to 2500) cm-1, and range is from (2500 to 3400) cm-1, known as the "high wave number region". Raman spectra also pliable the determination of the degree of saturation and unsaturation of oils. This characteristic is related to the value of iodine, and the degree of unsaturation can be used to classify and approve oils, which is especially useful with high-quality oils in the appearance of the vibration modes at 1155 cm-1 and 1525 cm-1. Adulteration of edible oils with cheaper oils is a major concern in the oil industry. The capabilities of a Raman spectrometer were checked to assess the purity of the samples (peanut spectrum and presses sesame spectrum). Raman spectroscopy allowed the examination of secondary components such as sterols, hydrocarbons, terpene alcohols and polyphenols. Raman spectroscopy is used because this innovative method provides fast, non-destructive and reagent-free measurements, samples do not need to be processed and do not require large volumes.
{"title":"Use of Raman Spectroscopy for Analysis and Detection of Some Sudanese Edible Oils","authors":"Mahasin Mohamed Dafaa Allah Banaga, A. Awadelgied, N. A. Muslet, N. Osman","doi":"10.11648/J.OPTICS.20211002.11","DOIUrl":"https://doi.org/10.11648/J.OPTICS.20211002.11","url":null,"abstract":"Vegetable edible oils provide high nutritional and health value in the Sudanese diet. It is also used in the pharmaceutical industry and an essential ingredient in cosmetics. This paper reviews the use of Raman spectroscopy for the analysis, quality and characterization of edible oils, including six types of oils (corn, extra virgin olive, sunflower, factory sesame, presses sesame, and peanut) purchased from local Sudanese stores. The results showed that the spectra of edible oils are similar, but they show some differences that, despite their smallness, allow them to be distinguished from each other. Divide the spectrum into the fingerprint region. The range ranges between (600 and 1800) cm-1 the silent region\", this spectral region is (1800 to 2500) cm-1, and range is from (2500 to 3400) cm-1, known as the \"high wave number region\". Raman spectra also pliable the determination of the degree of saturation and unsaturation of oils. This characteristic is related to the value of iodine, and the degree of unsaturation can be used to classify and approve oils, which is especially useful with high-quality oils in the appearance of the vibration modes at 1155 cm-1 and 1525 cm-1. Adulteration of edible oils with cheaper oils is a major concern in the oil industry. The capabilities of a Raman spectrometer were checked to assess the purity of the samples (peanut spectrum and presses sesame spectrum). Raman spectroscopy allowed the examination of secondary components such as sterols, hydrocarbons, terpene alcohols and polyphenols. Raman spectroscopy is used because this innovative method provides fast, non-destructive and reagent-free measurements, samples do not need to be processed and do not require large volumes.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":"132 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82708025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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. Talbi, Romain Duperrier, B. Delestre, G. Godard, M. Brunel
We report interferometric ice particle imaging and sizing in an icing wind tunnel with wind speeds of 70 m/s. Single particle interferograms are first analysed, size measurements are performed, and examples of possible reconstructed shapes are deduced from the interferometric images. Particle sizing is also performed in the case of ice particles whose out-of-focus images overlap, with or without Moiré phenomena. Results show that the IPI technique can be carried out for irregular rough particles in a critical environment such as in an icing wind tunnel with high wind speeds.
{"title":"Interferometric Ice Particle Imaging in a Wind Tunnel","authors":"M. Talbi, Romain Duperrier, B. Delestre, G. Godard, M. Brunel","doi":"10.3390/opt2040020","DOIUrl":"https://doi.org/10.3390/opt2040020","url":null,"abstract":"We report interferometric ice particle imaging and sizing in an icing wind tunnel with wind speeds of 70 m/s. Single particle interferograms are first analysed, size measurements are performed, and examples of possible reconstructed shapes are deduced from the interferometric images. Particle sizing is also performed in the case of ice particles whose out-of-focus images overlap, with or without Moiré phenomena. Results show that the IPI technique can be carried out for irregular rough particles in a critical environment such as in an icing wind tunnel with high wind speeds.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":"72 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86257124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Alina Fritschi, Chloe Gerber, Damian Eggler, Martin Loertscher
Exposing the retina to a simultaneous myopic defocus is an optical method that has shown a promising effect in slowing the progression of myopia. Optical treatments applying a simultaneous defocus are available in the form of soft contact lenses or multifocal lenses originally designed to correct presbyopia. Orthokeratology is another optical method that slows down the progression of myopia. With orthokeratology, it is hypothesized that a change in peripheral refraction could slow the progression of myopia. We aimed to measure the accommodation response between monofocal and multifocal contact lenses in young subjects. Additionally, we performed a ray-tracing simulation to visualize the quality of the retinal image and the refractive status in the retinal periphery. The accommodation and pupil size measurements were performed on 29 participants aged 24.03 ± 2.73 years with a refractive error (spherical equivalent) of −1.78 ± 1.06 D. With the multifocal lens in situ, our participants showed less accommodation in comparison to the monofocal contact lens (mean difference, 0.576 ± 0.36 D, p > 0.001) when focusing on a near target at 40 cm. Pupil size became smaller in both contact lens groups during an accommodation of 0.29 ± 0.69 mm, p ≤ 0.001 and 0.39 ± 0.46 mm, p ≤ 0.001 for monofocal and multifocal contact lenses, respectively. The ray-tracing model showed a degradation for central and peripheral vision with the multifocal contact lens. The peripheral refraction was relatively myopic in both contact lens conditions up to 30°. Even if the accommodation ability is without fault, parts of simultaneous myopic defocus are used for the near task. The peripheral refraction in the ray-tracing model was not different between the two contact lenses. This is contrary to the proposed hypothesis that myopic peripheral refraction slows down the progression of myopia in current optical methods.
将视网膜暴露于同时近视离焦是一种光学方法，在减缓近视进展方面显示出有希望的效果。使用同时离焦的光学治疗以软性隐形眼镜或多焦镜片的形式提供，最初设计用于矫正老花眼。角膜塑形镜是另一种减缓近视进展的光学方法。在角膜塑形术中，假设外周屈光的改变可以减缓近视的进展。我们的目的是测量年轻受试者在单焦点和多焦点隐形眼镜之间的调节反应。此外，我们进行了光线追踪模拟，以可视化视网膜图像的质量和视网膜周围的屈光状态。对29名年龄为24.03±2.73岁、屈光不正(球面等效)为- 1.78±1.06 D的参与者进行了调节和瞳孔大小测量。在原位多焦隐形眼镜的情况下，与单焦隐形眼镜相比，参与者在聚焦40 cm的近距离目标时表现出更小的调节(平均差为0.576±0.36 D, p > 0.001)。两组隐形眼镜的瞳孔在调节期间分别变小0.29±0.69 mm (p≤0.001)和0.39±0.46 mm (p≤0.001)。多焦点隐形眼镜的光线追踪模型显示出中央和周边视觉的退化。在两种隐形眼镜条件下，周围屈光度均相对较低，达30°。即使调节能力无故障，部分同时近视眼离焦也被用于近视眼任务。在光线追踪模型中，两种隐形眼镜的周围折射没有差异。这与当前光学方法中提出的近视外周屈光减缓近视进展的假设相反。
{"title":"Simultaneous Myopic Defocus for Myopia Control: Effect on Accommodation, Peripheral Refraction and Retinal Image Quality in Non-Presbyopic Patients","authors":"Alina Fritschi, Chloe Gerber, Damian Eggler, Martin Loertscher","doi":"10.3390/opt2040019","DOIUrl":"https://doi.org/10.3390/opt2040019","url":null,"abstract":"Exposing the retina to a simultaneous myopic defocus is an optical method that has shown a promising effect in slowing the progression of myopia. Optical treatments applying a simultaneous defocus are available in the form of soft contact lenses or multifocal lenses originally designed to correct presbyopia. Orthokeratology is another optical method that slows down the progression of myopia. With orthokeratology, it is hypothesized that a change in peripheral refraction could slow the progression of myopia. We aimed to measure the accommodation response between monofocal and multifocal contact lenses in young subjects. Additionally, we performed a ray-tracing simulation to visualize the quality of the retinal image and the refractive status in the retinal periphery. The accommodation and pupil size measurements were performed on 29 participants aged 24.03 ± 2.73 years with a refractive error (spherical equivalent) of −1.78 ± 1.06 D. With the multifocal lens in situ, our participants showed less accommodation in comparison to the monofocal contact lens (mean difference, 0.576 ± 0.36 D, p > 0.001) when focusing on a near target at 40 cm. Pupil size became smaller in both contact lens groups during an accommodation of 0.29 ± 0.69 mm, p ≤ 0.001 and 0.39 ± 0.46 mm, p ≤ 0.001 for monofocal and multifocal contact lenses, respectively. The ray-tracing model showed a degradation for central and peripheral vision with the multifocal contact lens. The peripheral refraction was relatively myopic in both contact lens conditions up to 30°. Even if the accommodation ability is without fault, parts of simultaneous myopic defocus are used for the near task. The peripheral refraction in the ray-tracing model was not different between the two contact lenses. This is contrary to the proposed hypothesis that myopic peripheral refraction slows down the progression of myopia in current optical methods.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86480665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
A. Tognazzi, D. Rocco, M. Gandolfi, A. Locatelli, L. Carletti, C. de Angelis
We propose a new sensing device based on all-optical nano-objects placed in a suspended periodic array. We demonstrate that the intensity-based sensing mechanism can measure environment refractive index change of the order of 1.8×10−6, which is close to record efficiencies in plasmonic devices.
{"title":"High Quality Factor Silicon Membrane Metasurface for Intensity-Based Refractive Index Sensing","authors":"A. Tognazzi, D. Rocco, M. Gandolfi, A. Locatelli, L. Carletti, C. de Angelis","doi":"10.3390/opt2030018","DOIUrl":"https://doi.org/10.3390/opt2030018","url":null,"abstract":"We propose a new sensing device based on all-optical nano-objects placed in a suspended periodic array. We demonstrate that the intensity-based sensing mechanism can measure environment refractive index change of the order of 1.8×10−6, which is close to record efficiencies in plasmonic devices.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80716073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Joaquín Fernández, M. Rodríguez-Vallejo, Noemí Burguera, Patrizia Salvestrini, N. Garzón
To evaluate the prediction error (PE) obtained in Phacoemulsification (Phaco) or Femtosecond (Femto) surgeries without considering posterior corneal astigmatism correction (non-PCA) versus the correction based on Abulafia-Koch + Medicontur (AK) and Barrett calculators in toric intraocular lens (IOL) power calculation. 58 right eyes were retrospectively retrieved from our database. Two groups formed by 28 and 30 eyes depending on the surgery type, Phaco or Femto respectively, were defined. Astigmatism PE were evaluated considering the approach used for calculation of the implanted IOL power (AK) versus the estimation of PEs in non-PCA and Barrett formula. A doubly-multivariate analysis was conducted to assess the differences between-surgery types, within-methods of calculation, and interaction. Mean centroid PE was significantly different between non-PCA, AK and Barrett approaches (p < 0.0005), and neither differences (p < 0.239) nor interaction (p = 0.672) between Phaco or Femto were found. Post-hoc univariate analysis showed a higher PE for the x-component of the non-PCA method versus AK (0.15 D, p < 0.0005) and non-PCA versus Barrett (0.18 D, p < 0.0005), though no differences were found between AK and Barrett (0.03 D, p = 0.93). Against-the-rule under-correction and with-the-rule overcorrection were found in both arms when PCA was not considered. Both calculators provide comparable clinical results.
评价不考虑角膜后散光矫正(非pca)的超声乳化(Phaco)或飞秒(Femto)手术与基于Abulafia-Koch + Medicontur (AK)和Barrett计算器的矫正在环形人工晶状体(IOL)度数计算中的预测误差(PE)。回顾性地从数据库中检索了58只右眼。根据手术类型分为Phaco组和Femto组，分别为28眼和30眼。将人工晶体植入术度数(AK)的计算方法与非pca和Barrett公式中植入术度数的估计方法进行比较，评估散光PE。采用双多变量分析来评估手术类型、计算方法和相互作用之间的差异。非pca法、AK法和Barrett法的平均质心PE差异有统计学意义(p < 0.0005)， Phaco法和Femto法的平均质心PE差异无统计学意义(p < 0.239)，且无交互作用(p = 0.672)。事后单变量分析显示，非pca方法的x分量的PE高于AK (0.15 D, p < 0.0005)和非pca方法的PE高于Barrett (0.18 D, p < 0.0005)，尽管AK和Barrett之间没有差异(0.03 D, p = 0.93)。在不考虑PCA的情况下，两臂均出现反规则校正不足和符合规则校正过度。两种计算器提供了相似的临床结果。
{"title":"Toric Intraocular Lens Results Considering Posterior Corneal Astigmatism with Online Calculators: Phacoemulsification vs. Femtosecond","authors":"Joaquín Fernández, M. Rodríguez-Vallejo, Noemí Burguera, Patrizia Salvestrini, N. Garzón","doi":"10.3390/opt2030017","DOIUrl":"https://doi.org/10.3390/opt2030017","url":null,"abstract":"To evaluate the prediction error (PE) obtained in Phacoemulsification (Phaco) or Femtosecond (Femto) surgeries without considering posterior corneal astigmatism correction (non-PCA) versus the correction based on Abulafia-Koch + Medicontur (AK) and Barrett calculators in toric intraocular lens (IOL) power calculation. 58 right eyes were retrospectively retrieved from our database. Two groups formed by 28 and 30 eyes depending on the surgery type, Phaco or Femto respectively, were defined. Astigmatism PE were evaluated considering the approach used for calculation of the implanted IOL power (AK) versus the estimation of PEs in non-PCA and Barrett formula. A doubly-multivariate analysis was conducted to assess the differences between-surgery types, within-methods of calculation, and interaction. Mean centroid PE was significantly different between non-PCA, AK and Barrett approaches (p < 0.0005), and neither differences (p < 0.239) nor interaction (p = 0.672) between Phaco or Femto were found. Post-hoc univariate analysis showed a higher PE for the x-component of the non-PCA method versus AK (0.15 D, p < 0.0005) and non-PCA versus Barrett (0.18 D, p < 0.0005), though no differences were found between AK and Barrett (0.03 D, p = 0.93). Against-the-rule under-correction and with-the-rule overcorrection were found in both arms when PCA was not considered. Both calculators provide comparable clinical results.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90289986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
The problem of overcoming the diffraction limit does not have an unambiguously advantageous solution because of the competing nature of different beams’ parameters, such as the focal spot size, energy efficiency, and sidelobe level. The possibility to overcome the diffraction limit with suppressed sidelobes out of the near-field zone using superoscillating functions was investigated in detail. Superoscillation is a phenomenon in which a superposition of harmonic functions contains higher spatial frequencies than any of the terms in the superposition. Two types of superoscillating one-dimensional signals were considered, and simulation of their propagation in the near diffraction zone based on plane waves expansion was performed. A comparative numerical study showed the possibility of overcoming the diffraction limit with a reduced level of sidelobes at a certain distance outside the zone of evanescent waves.
{"title":"Study of Superoscillating Functions Application to Overcome the Diffraction Limit with Suppressed Sidelobes","authors":"S. Khonina, Ekaterina Ponomareva, M. A. Butt","doi":"10.3390/opt2030015","DOIUrl":"https://doi.org/10.3390/opt2030015","url":null,"abstract":"The problem of overcoming the diffraction limit does not have an unambiguously advantageous solution because of the competing nature of different beams’ parameters, such as the focal spot size, energy efficiency, and sidelobe level. The possibility to overcome the diffraction limit with suppressed sidelobes out of the near-field zone using superoscillating functions was investigated in detail. Superoscillation is a phenomenon in which a superposition of harmonic functions contains higher spatial frequencies than any of the terms in the superposition. Two types of superoscillating one-dimensional signals were considered, and simulation of their propagation in the near diffraction zone based on plane waves expansion was performed. A comparative numerical study showed the possibility of overcoming the diffraction limit with a reduced level of sidelobes at a certain distance outside the zone of evanescent waves.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":"173 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76914706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Optically transparent materials are being found in an ever-increasing array of technological applications within industries, such as automotive and communications. These industries are beginning to realize the importance of implementing surface engineering techniques to enhance the surface properties of materials. On account of the importance of surface engineering, this paper details the use of a relatively inexpensive diode-pumped solid state (DPSS) Nd:YVO4 laser to modify the surfaces of fused silica glass, diamond, and sapphire on a micrometre scale. Using threshold fluence analysis, it was identified that, for this particular laser system, the threshold fluence for diamond and sapphire ranged between 10 Jcm−2 and 35 Jcm−2 for a laser wavelength of 355 nm, dependent on the cumulative effects arising from the number of incident pulses. Through optical microscopy and scanning electron microscopy, it was found that the quality of processing resulting from the Nd:YVO4 laser varied with each of the materials. For fused silica glass, considerable cracking and deformation occurred. For sapphire, good quality features were produced, albeit with the formation of debris, indicating the requirement for post-processing to remove the observed debris. The diamond material gave rise to the best quality results, with extremely well defined micrometre features and minimal debris formation, comparative to alternative techniques such as femtosecond laser surface engineering.
{"title":"Micro-Machining of Diamond, Sapphire and Fused Silica Glass Using a Pulsed Nano-Second Nd:YVO4 Laser","authors":"D. Waugh, C. Walton","doi":"10.3390/opt2030016","DOIUrl":"https://doi.org/10.3390/opt2030016","url":null,"abstract":"Optically transparent materials are being found in an ever-increasing array of technological applications within industries, such as automotive and communications. These industries are beginning to realize the importance of implementing surface engineering techniques to enhance the surface properties of materials. On account of the importance of surface engineering, this paper details the use of a relatively inexpensive diode-pumped solid state (DPSS) Nd:YVO4 laser to modify the surfaces of fused silica glass, diamond, and sapphire on a micrometre scale. Using threshold fluence analysis, it was identified that, for this particular laser system, the threshold fluence for diamond and sapphire ranged between 10 Jcm−2 and 35 Jcm−2 for a laser wavelength of 355 nm, dependent on the cumulative effects arising from the number of incident pulses. Through optical microscopy and scanning electron microscopy, it was found that the quality of processing resulting from the Nd:YVO4 laser varied with each of the materials. For fused silica glass, considerable cracking and deformation occurred. For sapphire, good quality features were produced, albeit with the formation of debris, indicating the requirement for post-processing to remove the observed debris. The diamond material gave rise to the best quality results, with extremely well defined micrometre features and minimal debris formation, comparative to alternative techniques such as femtosecond laser surface engineering.","PeriodicalId":54548,"journal":{"name":"Progress in Optics","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73256355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：