Ruhana Nishad, Lutfun Nahar Asha, K. Shaha, A. B. M. A. Hossain, Abdul Khaleque
{"title":"MULTI-LAYERED CLADDING BASED ULTRA-LOW LOSS, SINGLE MODE ANTIRESONANT HOLLOW CORE FIBERS","authors":"Ruhana Nishad, Lutfun Nahar Asha, K. Shaha, A. B. M. A. Hossain, Abdul Khaleque","doi":"10.1364/ome.504207","DOIUrl":"https://doi.org/10.1364/ome.504207","url":null,"abstract":"","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":"52 12","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139007025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Muhammad Danial Shafqat, Nasir Mahmood, Jehan Akbar, Muhammad Zubair, Yehia Massoud, and Muhammad Qasim Mehmood
Perfect vortex (PV) beams exhibiting topological charge-insensitive annular intensity distribution appear as a striking hotspot for significant advances in optical communication and quantum optics and have great potential to fulfill the requirements of futuristic optical communication systems. The recently developed planar photonics devices possessed an unprecedented ability for complex wavefront shaping at the micron scale; however, the limited working bandwidth and abruptly diverging light behavior of the current PV beam-generating planar photonics devices roadblock their applicability in practical systems. This work demonstrates a single-cell driven broadband planar photonics platform to realize the nondiffracting-type PV beams for the visible spectrum. These PV beams exhibit long propagating constant-sized doughnuts for different topological charges and exhibit expected broadband response. The proposed concept is verified by numerically studying multiple meta-devices capable of generating nondiffracting-type PV beams. The presented photonics platform may bring considerable advances in real-life applications like machine vision.
{"title":"Broadband multifunctional metasurfaces for concentric perfect vortex beam generation via trigonometric functions","authors":"Muhammad Danial Shafqat, Nasir Mahmood, Jehan Akbar, Muhammad Zubair, Yehia Massoud, and Muhammad Qasim Mehmood","doi":"10.1364/ome.510015","DOIUrl":"https://doi.org/10.1364/ome.510015","url":null,"abstract":"Perfect vortex (PV) beams exhibiting topological charge-insensitive annular intensity distribution appear as a striking hotspot for significant advances in optical communication and quantum optics and have great potential to fulfill the requirements of futuristic optical communication systems. The recently developed planar photonics devices possessed an unprecedented ability for complex wavefront shaping at the micron scale; however, the limited working bandwidth and abruptly diverging light behavior of the current PV beam-generating planar photonics devices roadblock their applicability in practical systems. This work demonstrates a single-cell driven broadband planar photonics platform to realize the nondiffracting-type PV beams for the visible spectrum. These PV beams exhibit long propagating constant-sized doughnuts for different topological charges and exhibit expected broadband response. The proposed concept is verified by numerically studying multiple meta-devices capable of generating nondiffracting-type PV beams. The presented photonics platform may bring considerable advances in real-life applications like machine vision.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":"38 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138573002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Perovskite-silicon tandem solar cells have captured the attention of the solar cell research community due to the advantages of perovskites, such as, an easy fabrication process using sol-gel methods and silicon bottom cells that can be fabricated using well-established fabrication techniques. The present study discusses the design, optimization, and numerical analysis related to the role of nanostructured anti-reflection coating design for perovskite (MAPbI3) silicon tandem solar cells. In the design, the top cell is taken as MAPbI3 and the bottom cell is C-silicon. The anti-reflection coating is designed with SiO2 nanoparticles embedded in ITO. These nanostructured top anti-reflection coating results are compared with its planar top cell counterpart. SiO2 nanoparticle diameter and interparticle separation are optimized to get maximum absorption in the top cell. Upon optimization, it was found that a design having SiO2 nanoparticles with a diameter of 60 nm and no interparticle separation showed the most reduction in reflection, which in turn led to an increase in absorption in the top cell. The proposed structure enhances current density by 8.3% over the planar cell. This top cell current is matched to the bottom silicon thickness. These findings were validated using Mie scattering and the Bruggmann effective medium approximation.
{"title":"Nanostructured anti-reflection coating for absorption enhancement in perovskite silicon tandem solar cells","authors":"B. Kranthi Kumar and Nikhil Deep Gupta","doi":"10.1364/ome.503990","DOIUrl":"https://doi.org/10.1364/ome.503990","url":null,"abstract":"Perovskite-silicon tandem solar cells have captured the attention of the solar cell research community due to the advantages of perovskites, such as, an easy fabrication process using sol-gel methods and silicon bottom cells that can be fabricated using well-established fabrication techniques. The present study discusses the design, optimization, and numerical analysis related to the role of nanostructured anti-reflection coating design for perovskite (MAPbI<sub>3</sub>) silicon tandem solar cells. In the design, the top cell is taken as MAPbI<sub>3</sub> and the bottom cell is C-silicon. The anti-reflection coating is designed with SiO<sub>2</sub> nanoparticles embedded in ITO. These nanostructured top anti-reflection coating results are compared with its planar top cell counterpart. SiO<sub>2</sub> nanoparticle diameter and interparticle separation are optimized to get maximum absorption in the top cell. Upon optimization, it was found that a design having SiO<sub>2</sub> nanoparticles with a diameter of 60 nm and no interparticle separation showed the most reduction in reflection, which in turn led to an increase in absorption in the top cell. The proposed structure enhances current density by 8.3% over the planar cell. This top cell current is matched to the bottom silicon thickness. These findings were validated using Mie scattering and the Bruggmann effective medium approximation.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":"38 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138573263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sahar Sohrabi, Hedieh Pazokian, Bijan Ghafary, and Mahmood Mollabashi
Adhesion of bacteria to a surface followed by biofilm formation causes many problems in human health care and, in some cases, can even cause human death. Therefore, reducing bacterial attachment to surfaces and antibacterial surface fabrication are two of the most important issues in many applications, including healthcare, medical, food packaging, etc. Polycarbonate (PC) is one of the most widely used polymers in medicine. However, it does not have antibacterial properties. On the other hand, laser treatment is used as a standard method for surface modification of different materials. In this paper, excimer laser irradiation at a fluence below the ablation threshold was used for surface patterning and modification of the polycarbonate sample, aiming to improve its antibacterial properties. The results show that super-hydrophilic nanostructured polycarbonate surfaces have antibacterial properties compared to non-treated PC, which has no antibacterial properties.
细菌附着在物体表面并形成生物膜会给人类健康带来许多问题，在某些情况下甚至会导致人类死亡。因此，减少细菌对表面的附着和抗菌表面制造是保健、医疗、食品包装等许多应用中最重要的两个问题。聚碳酸酯（PC）是医疗领域应用最广泛的聚合物之一。然而，它并不具备抗菌特性。另一方面，激光处理是对不同材料进行表面改性的标准方法。本文使用低于烧蚀阈值的准分子激光照射聚碳酸酯样品，对其进行表面图案化和改性处理，以提高其抗菌性能。结果表明，与未处理的 PC 相比，超亲水纳米结构的聚碳酸酯表面具有抗菌性能，而未处理的 PC 没有抗菌性能。
{"title":"Super-hydrophilic nano-structured surface with antibacterial properties","authors":"Sahar Sohrabi, Hedieh Pazokian, Bijan Ghafary, and Mahmood Mollabashi","doi":"10.1364/ome.505843","DOIUrl":"https://doi.org/10.1364/ome.505843","url":null,"abstract":"Adhesion of bacteria to a surface followed by biofilm formation causes many problems in human health care and, in some cases, can even cause human death. Therefore, reducing bacterial attachment to surfaces and antibacterial surface fabrication are two of the most important issues in many applications, including healthcare, medical, food packaging, etc. Polycarbonate (PC) is one of the most widely used polymers in medicine. However, it does not have antibacterial properties. On the other hand, laser treatment is used as a standard method for surface modification of different materials. In this paper, excimer laser irradiation at a fluence below the ablation threshold was used for surface patterning and modification of the polycarbonate sample, aiming to improve its antibacterial properties. The results show that super-hydrophilic nanostructured polycarbonate surfaces have antibacterial properties compared to non-treated PC, which has no antibacterial properties.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":"92 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138560197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Torquato and Kim [Phys. Rev. X 11, 296 021002 (2021)] derived exact nonlocal strong-contrast expansions of the effective dynamic dielectric constant tensor that treat general three-dimensional (3D) two-phase composites, which are valid well beyond the long-wavelength regime. Here, we demonstrate that truncating this general rapidly converging series at the two- and three-point levels is a powerful theoretical tool for extracting accurate approximations suited for various microstructural symmetries. We derive such closed-form formulas applicable to transverse polarization in layered media and transverse magnetic polarization in transversely isotropic media, respectively. We use these formulas to estimate effective dielectric constant for models of 3D disordered hyperuniform layered and transversely isotropic media: nonstealthy hyperuniform and stealthy hyperuniform (SHU) media. In particular, we show that SHU media are perfectly transparent (trivially implying no Anderson localization, in principle) within finite wave number intervals through the third-order terms. For these two models, we validate that the second-order formulas, which depend on the spectral density, are already very accurate well beyond the long-wavelength regime by showing very good agreement with the finite-difference time-domain simulations. The high predictive power of the second-order formulas implies that higher-order contributions are negligibly small, and thus, it very accurately approximates multiple scattering effects. Therefore, there can be no Anderson localization in practice within the predicted perfect transparency interval in SHU media because the localization length should be very large compared to any practically large sample size. Our predictive theory provides a foundation for the inverse design of novel effective wave characteristics of disordered and statistically anisotropic structures.
托尔夸托和金[物理学]。Rev. X 11, 296 021002(2021)]导出了处理一般三维(3D)两相复合材料的有效动态介电常数张量的精确非局部强对比展开式，其有效范围远远超出长波长范围。在这里，我们证明了在两点和三点水平截断这种一般快速收敛序列是提取适合于各种微观结构对称性的精确近似的强大理论工具。我们分别导出了适用于层状介质中的横向极化和横向各向同性介质中的横向磁极化的封闭公式。我们使用这些公式来估计三维无序超均匀层状和横向各向同性介质模型的有效介电常数:非隐身超均匀和隐身超均匀(SHU)介质。特别是，我们表明SHU介质在有限的波数间隔内通过三阶项是完全透明的(通常意味着原则上没有安德森局域化)。对于这两个模型，我们验证了依赖于谱密度的二阶公式，通过与有限差分时域模拟显示出非常好的一致性，已经非常精确地超出了长波范围。二阶公式的高预测能力意味着高阶贡献可以忽略不计，因此，它非常准确地近似于多重散射效应。因此，在SHU介质中，在预测的完美透明区间内，在实践中不可能出现Anderson定位，因为与实际的大样本量相比，定位长度应该非常大。我们的预测理论为无序和统计各向异性结构的新型有效波特性的反设计提供了基础。
{"title":"Theoretical Prediction of the Effective Dynamic Dielectric Constant of Disordered Hyperuniform Anisotropic Composites Beyond the Long-Wavelength Regime","authors":"Jaeuk Kim, salvatore torquato","doi":"10.1364/ome.507918","DOIUrl":"https://doi.org/10.1364/ome.507918","url":null,"abstract":"Torquato and Kim [Phys. Rev. X 11, 296 021002 (2021)] derived exact nonlocal strong-contrast expansions of the effective dynamic dielectric constant tensor that treat general three-dimensional (3D) two-phase composites, which are valid well beyond the long-wavelength regime. Here, we demonstrate that truncating this general rapidly converging series at the two- and three-point levels is a powerful theoretical tool for extracting accurate approximations suited for various microstructural symmetries. We derive such closed-form formulas applicable to transverse polarization in layered media and transverse magnetic polarization in transversely isotropic media, respectively. We use these formulas to estimate effective dielectric constant for models of 3D disordered hyperuniform layered and transversely isotropic media: nonstealthy hyperuniform and stealthy hyperuniform (SHU) media. In particular, we show that SHU media are perfectly transparent (trivially implying no Anderson localization, in principle) within finite wave number intervals through the third-order terms. For these two models, we validate that the second-order formulas, which depend on the spectral density, are already very accurate well beyond the long-wavelength regime by showing very good agreement with the finite-difference time-domain simulations. The high predictive power of the second-order formulas implies that higher-order contributions are negligibly small, and thus, it very accurately approximates multiple scattering effects. Therefore, there can be no Anderson localization in practice within the predicted perfect transparency interval in SHU media because the localization length should be very large compared to any practically large sample size. Our predictive theory provides a foundation for the inverse design of novel effective wave characteristics of disordered and statistically anisotropic structures.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":"51 43","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138592935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shanglin Chen, Jian Sun, Jingping Li, Kui Yi, Chenfei Wang, Jianda Shao, and Meiping Zhu
A lateral thickness distribution control model for magnetron sputter-deposited coatings was established using shadow masks. The sputtering yield distributions were investigated in detail, particularly the variation trend from straight to curved tracks, based on the erosion profiles of rectangular targets. On this basis, a mathematical model for a planetary rotation system was established to simulate the thickness distribution of coatings on different substrates, including flat, spherical, and aspherical shapes, accurately. A shadow mask with multi-Gaussian outlines was proposed, and the coating thickness was effectively controlled according to specific distribution requirements by optimizing the profile parameters of the masks using a genetic algorithm. Flat and ellipsoidal substrates were used to prepare Mo and Si monolayer coatings to verify the effectiveness of this model. Although the diameters of the substrates were close to the lengths of the rectangular targets, the results showed that uniform coatings were obtained on the flat substrate, whereas the ellipsoidal substrate exhibited high-precision gradient coatings, with maximum deviations below 0.5%, which proved the validity of this approach.
{"title":"Controlling lateral thickness distributions of magnetron sputtering deposited coatings using shadow masks","authors":"Shanglin Chen, Jian Sun, Jingping Li, Kui Yi, Chenfei Wang, Jianda Shao, and Meiping Zhu","doi":"10.1364/ome.500104","DOIUrl":"https://doi.org/10.1364/ome.500104","url":null,"abstract":"A lateral thickness distribution control model for magnetron sputter-deposited coatings was established using shadow masks. The sputtering yield distributions were investigated in detail, particularly the variation trend from straight to curved tracks, based on the erosion profiles of rectangular targets. On this basis, a mathematical model for a planetary rotation system was established to simulate the thickness distribution of coatings on different substrates, including flat, spherical, and aspherical shapes, accurately. A shadow mask with multi-Gaussian outlines was proposed, and the coating thickness was effectively controlled according to specific distribution requirements by optimizing the profile parameters of the masks using a genetic algorithm. Flat and ellipsoidal substrates were used to prepare Mo and Si monolayer coatings to verify the effectiveness of this model. Although the diameters of the substrates were close to the lengths of the rectangular targets, the results showed that uniform coatings were obtained on the flat substrate, whereas the ellipsoidal substrate exhibited high-precision gradient coatings, with maximum deviations below 0.5%, which proved the validity of this approach.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":"67 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138556969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this letter, we investigated the Raman scattering characteristics of a series of aTeO2-(90-a)BaF2-10Y2O3 (a = 85, 80, 75, 70, 65, 60, 55 mol%), bTeO2-(95-b)BaF2-5Y2O3 (b = 90, 85, 80, 75, 70, 65, 60, 55, 50 mol%) and cTeO2-(100-c)BaF2 (c = 95, 90, 85, 80, 75, 70, 65, 60 mol%) fluorotellurite glasses. With increasing the concentration of BaF2, the peak Raman gain coefficient at 785 cm−1 increased while the Raman gain bandwidth (full spectral width at half maximum of the Raman peaks around 785 cm−1) decreased, which was attributed to the increasing proportion of non-bridge oxygen bonds in the fluorotellurite glass systems. The same results were also observed for the case of the increasing of the concentration of Y2O3. In these samples, the 50TeO2-40BaF2-10Y2O3 glass has the largest Raman gain coefficient of 29.9 × 10−13 m/W, and the 95TeO2-5BaF2 glass has the widest Raman gain bandwidth of 7.35 THz for the pumping laser at 633 nm. Furthermore, the first-order Raman Stokes light peaked at ∼2373 nm was obtained by using fluorotellurite fiber based on the above glasses as Raman gain medium and a 2000nm picoseconds laser as pump light. Our results provide guidance for further improving the performance of Raman fiber lasers or amplifiers based on fluorotellurite fibers.
{"title":"Effect of BaF2 and Y2O3 on the Raman scattering characteristics of fluorotellurite glasses","authors":"Qian Zhang, Yadong Jiao, Zhixu Jia, Lili Wang, Weiping Qin, and Guanshi Qin","doi":"10.1364/ome.506523","DOIUrl":"https://doi.org/10.1364/ome.506523","url":null,"abstract":"In this letter, we investigated the Raman scattering characteristics of a series of aTeO<sub>2</sub>-(90-a)BaF<sub>2</sub>-10Y<sub>2</sub>O<sub>3</sub> (a = 85, 80, 75, 70, 65, 60, 55 mol%), bTeO<sub>2</sub>-(95-b)BaF<sub>2</sub>-5Y<sub>2</sub>O<sub>3</sub> (b = 90, 85, 80, 75, 70, 65, 60, 55, 50 mol%) and cTeO<sub>2</sub>-(100-c)BaF<sub>2</sub> (c = 95, 90, 85, 80, 75, 70, 65, 60 mol%) fluorotellurite glasses. With increasing the concentration of BaF<sub>2</sub>, the peak Raman gain coefficient at 785 cm<sup>−1</sup> increased while the Raman gain bandwidth (full spectral width at half maximum of the Raman peaks around 785 cm<sup>−1</sup>) decreased, which was attributed to the increasing proportion of non-bridge oxygen bonds in the fluorotellurite glass systems. The same results were also observed for the case of the increasing of the concentration of Y<sub>2</sub>O<sub>3</sub>. In these samples, the 50TeO<sub>2</sub>-40BaF<sub>2</sub>-10Y<sub>2</sub>O<sub>3</sub> glass has the largest Raman gain coefficient of 29.9 × 10<sup>−13</sup> m/W, and the 95TeO<sub>2</sub>-5BaF<sub>2</sub> glass has the widest Raman gain bandwidth of 7.35 THz for the pumping laser at 633 nm. Furthermore, the first-order Raman Stokes light peaked at ∼2373 nm was obtained by using fluorotellurite fiber based on the above glasses as Raman gain medium and a 2000nm picoseconds laser as pump light. Our results provide guidance for further improving the performance of Raman fiber lasers or amplifiers based on fluorotellurite fibers.","PeriodicalId":19548,"journal":{"name":"Optical Materials Express","volume":"20 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138545396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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