Pub Date : 2024-04-16DOI: 10.1088/2040-8986/ad3b19
Haomai Lei, Bin Luo, Jianfei Hu, Jiming Wang, Tong Wu, Youwen Liu
The optical topology, which serves as a stable spatial electromagnetic structure, offers a new dimension for applications in the field of optical information processing, transmission, and storage. In recent years, there has been an increasing focus on these spatially structured light fields. By reversing the radiation of orthogonal dipole pairs, we propose an approach to generate Meron topologies within the focused light field while also investigating the evolution of the Meron structure along the longitudinal axis. Through introducing a dipole placed along the z-axis, we achieve precise positioning and fine adjustment of the topological center. The stability of Meron under a high numerical aperture objective lens (NA = 0.95) can be effectively demonstrated.
光学拓扑结构作为一种稳定的空间电磁结构，为光信息处理、传输和存储领域的应用提供了一个新的维度。近年来，人们越来越关注这些空间结构光场。通过反转正交偶极子对的辐射，我们提出了一种在聚焦光场内生成梅隆拓扑结构的方法，同时还研究了梅隆结构沿纵轴的演变。通过引入沿 Z 轴放置的偶极子，我们实现了拓扑中心的精确定位和微调。在高数值孔径物镜（NA = 0.95）的作用下，Meron 的稳定性得到了有效证明。
{"title":"Creation and manipulation of optical Meron topologies in tightly focused electromagnetic field","authors":"Haomai Lei, Bin Luo, Jianfei Hu, Jiming Wang, Tong Wu, Youwen Liu","doi":"10.1088/2040-8986/ad3b19","DOIUrl":"https://doi.org/10.1088/2040-8986/ad3b19","url":null,"abstract":"The optical topology, which serves as a stable spatial electromagnetic structure, offers a new dimension for applications in the field of optical information processing, transmission, and storage. In recent years, there has been an increasing focus on these spatially structured light fields. By reversing the radiation of orthogonal dipole pairs, we propose an approach to generate Meron topologies within the focused light field while also investigating the evolution of the Meron structure along the longitudinal axis. Through introducing a dipole placed along the <italic toggle=\"yes\">z</italic>-axis, we achieve precise positioning and fine adjustment of the topological center. The stability of Meron under a high numerical aperture objective lens (NA = 0.95) can be effectively demonstrated.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"440 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140608949","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}
Pub Date : 2024-04-15DOI: 10.1088/2040-8986/ad3b18
Longfei Yin, Tiantian Liu, Xinlong Mai, Shilun Sun, Pengqi Yin, Guohua Wu, Bin Luo
Ghost imaging (GI) has found application across diverse fields owing to its distinctive benefits. When employing the rotating ground-glass scheme and utilizing second-order correlation for image reconstruction, the efficiency of imaging is hindered by the multiple sampling of reference patterns. To address this, the orthonormalization method has been employed to enhance image quality and reduce the required number of measurements. Despite its effectiveness, the original orthonormalization method is prone to accumulating imaging noise and errors as the number of measurements increases, leading to a significant degradation in image quality. To overcome this limitation, this paper introduces the grouped orthonormalization method (GO-GI) as an extension of the orthonormalization technique. By adjusting the ‘group size’, this method enables control over the accumulation of errors, resulting in an improvement in image quality. The evaluation of image quality in terms of Contrast-to-Noise demonstrates the significant advantages of the GO-GI method in both simulation and experimental results. This study establishes the GO-GI method as a simple yet practical approach in the realm of GI.
{"title":"Research on the grouped orthonormalization method in ghost imaging","authors":"Longfei Yin, Tiantian Liu, Xinlong Mai, Shilun Sun, Pengqi Yin, Guohua Wu, Bin Luo","doi":"10.1088/2040-8986/ad3b18","DOIUrl":"https://doi.org/10.1088/2040-8986/ad3b18","url":null,"abstract":"Ghost imaging (GI) has found application across diverse fields owing to its distinctive benefits. When employing the rotating ground-glass scheme and utilizing second-order correlation for image reconstruction, the efficiency of imaging is hindered by the multiple sampling of reference patterns. To address this, the orthonormalization method has been employed to enhance image quality and reduce the required number of measurements. Despite its effectiveness, the original orthonormalization method is prone to accumulating imaging noise and errors as the number of measurements increases, leading to a significant degradation in image quality. To overcome this limitation, this paper introduces the grouped orthonormalization method (GO-GI) as an extension of the orthonormalization technique. By adjusting the ‘group size’, this method enables control over the accumulation of errors, resulting in an improvement in image quality. The evaluation of image quality in terms of Contrast-to-Noise demonstrates the significant advantages of the GO-GI method in both simulation and experimental results. This study establishes the GO-GI method as a simple yet practical approach in the realm of GI.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"18 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140608948","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}
Pub Date : 2024-04-11DOI: 10.1088/2040-8986/ad3a78
Kirill Koshelev, Ivan Toftul, Yongsop Hwang, Yuri Kivshar
We generalize the concept of optical scattering matrix (S-matrix) to characterize harmonic generation and frequency mixing in planar metasurfaces in the limit of undepleted pump approximation. We show that the symmetry properties of such nonlinear S-matrix are determined by the metasurface symmetries at the macroscopic and microscopic scale. We demonstrate that for description of degenerate frequency mixing processes such as optical harmonic generation, the multidimensional S-matrix can be replaced with a reduced two-dimensional S-matrix. We show that for metasurfaces possessing specific point group symmetries, the selection rules determining the transformation of the reduced nonlinear S-matrix are simplified substantially and can be expressed in a compact form. We apply the developed approach to analyze chiral harmonic generation in nonlinear metasurfaces with various symmetries including rotational, inversion, in-plane mirror, and out-of-plane mirror symmetries. For each of those symmetries, we confirm the results of the developed analysis by full-wave numerical calculations. We believe our results provide a new paradigm for engineering nonlinear optical properties of metasurfaces which may find applications in active and nonlinear optics, biosensing, and quantum information processing.
我们将光学散射矩阵（S-matrix）的概念加以推广，以描述在未耗尽泵近似极限下平面元表面的谐波产生和频率混合。我们表明，这种非线性 S 矩阵的对称特性是由宏观和微观尺度上的元表面对称性决定的。我们证明，在描述光谐波产生等退化混频过程时，可以用缩小的二维 S 矩阵代替多维 S 矩阵。我们证明，对于具有特定点群对称性的元表面，决定缩减非线性 S 矩阵变换的选择规则被大大简化，并能以紧凑的形式表达。我们运用所开发的方法分析了具有各种对称性（包括旋转对称性、反转对称性、面内镜像对称性和面外镜像对称性）的非线性元表面中手性谐波的产生。对于每种对称性，我们都通过全波数值计算证实了所开发的分析结果。我们相信，我们的研究成果为元表面的非线性光学特性工程学提供了一种新的范式，它可能会在有源和非线性光学、生物传感和量子信息处理中得到应用。
{"title":"Scattering matrix for chiral harmonic generation and frequency mixing in nonlinear metasurfaces","authors":"Kirill Koshelev, Ivan Toftul, Yongsop Hwang, Yuri Kivshar","doi":"10.1088/2040-8986/ad3a78","DOIUrl":"https://doi.org/10.1088/2040-8986/ad3a78","url":null,"abstract":"We generalize the concept of optical scattering matrix (<italic toggle=\"yes\">S</italic>-matrix) to characterize harmonic generation and frequency mixing in planar metasurfaces in the limit of undepleted pump approximation. We show that the symmetry properties of such nonlinear <italic toggle=\"yes\">S</italic>-matrix are determined by the metasurface symmetries at the macroscopic and microscopic scale. We demonstrate that for description of degenerate frequency mixing processes such as optical harmonic generation, the multidimensional <italic toggle=\"yes\">S</italic>-matrix can be replaced with a reduced two-dimensional <italic toggle=\"yes\">S</italic>-matrix. We show that for metasurfaces possessing specific point group symmetries, the selection rules determining the transformation of the reduced nonlinear <italic toggle=\"yes\">S</italic>-matrix are simplified substantially and can be expressed in a compact form. We apply the developed approach to analyze <italic toggle=\"yes\">chiral harmonic generation</italic> in nonlinear metasurfaces with various symmetries including rotational, inversion, in-plane mirror, and out-of-plane mirror symmetries. For each of those symmetries, we confirm the results of the developed analysis by full-wave numerical calculations. We believe our results provide a new paradigm for engineering nonlinear optical properties of metasurfaces which may find applications in active and nonlinear optics, biosensing, and quantum information processing.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"36 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140614321","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}
Multilayers (MLs) are a good choice for high-harmonic generation (HHG) sources for selecting single-wavelength radiation. MLs working around 30.4 nm with a significantly reduced bandwidth based on high Bragg order reflection have been designed and fabricated. The narrowband MLs were characterized using grazing incidence x-ray reflectometry, extreme ultraviolet reflectivity, and intrinsic stress measurements. The results indicate that Mg/SiC MLs designed with 3rd Bragg order have narrowest bandwidth of 0.71 nm (full width half maximum) with a spectral resolution (λ/Δλ) of 42, and reflectance of 30% under near normal incidence geometry. Based on these results, the simulation of narrowband MLs working at large incident angles demonstrates that 3rd Bragg order ML has a better spectral selectivity compared with 1st Bragg order ML for HHG sources.
多层膜（ML）是选择单波长辐射的高次谐波发生（HHG）源的良好选择。我们设计并制造了基于高布拉格阶反射的工作波长在 30.4 纳米左右、带宽显著降低的多层膜。使用掠入射 X 射线反射仪、极紫外反射率和本征应力测量法对窄带 ML 进行了表征。结果表明，采用第三布拉格阶设计的 Mg/SiC ML 在近正常入射几何条件下，最窄带宽为 0.71 nm（全宽半最大值），光谱分辨率（λ/Δλ）为 42，反射率为 30%。基于这些结果，对在大入射角下工作的窄带 ML 的模拟表明，对于 HHG 光源，第 3 勃拉格阶 ML 与第 1 勃拉格阶 ML 相比具有更好的光谱选择性。
{"title":"Narrowband Mg/SiC multilayer mirror working as high-harmonic selector at 30.4 nm wavelength","authors":"Zhe Zhang, Runze Qi, Qiushi Huang, Yufei Feng, Zhong Zhang, Tonglin Huo, Hongjun Zhou, Zhanshan Wang","doi":"10.1088/2040-8986/ad3a79","DOIUrl":"https://doi.org/10.1088/2040-8986/ad3a79","url":null,"abstract":"Multilayers (MLs) are a good choice for high-harmonic generation (HHG) sources for selecting single-wavelength radiation. MLs working around 30.4 nm with a significantly reduced bandwidth based on high Bragg order reflection have been designed and fabricated. The narrowband MLs were characterized using grazing incidence x-ray reflectometry, extreme ultraviolet reflectivity, and intrinsic stress measurements. The results indicate that Mg/SiC MLs designed with 3rd Bragg order have narrowest bandwidth of 0.71 nm (full width half maximum) with a spectral resolution (<italic toggle=\"yes\">λ/</italic>Δ<italic toggle=\"yes\">λ</italic>) of 42, and reflectance of 30% under near normal incidence geometry. Based on these results, the simulation of narrowband MLs working at large incident angles demonstrates that 3rd Bragg order ML has a better spectral selectivity compared with 1st Bragg order ML for HHG sources.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"97 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140614326","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}
Inverse design methodologies effectively optimize many design parameters of a photonic device with respect to a primary objective, uncovering locally optimal designs in a typically non-convex parameter space. Often, a variety of secondary objectives (performance metrics) also need to be considered before fabrication takes place. Hence, a large collection of optimized designs is useful, as their performance on secondary objectives often varies. For certain classes of components such as shape-optimized devices, the most efficient optimization approach is to begin with 2D optimization from random parameter initialization and then follow up with 3D re-optimization. Nevertheless, the latter stage is substantially time- and resource-intensive. Thus, obtaining a desired collection of optimized designs through repeated 3D optimizations is a computational challenge. To address this issue, a machine learning-based regression model is proposed to reduce the computation cost involved in the 3D optimization stage. The regression model correlates the 2D and 3D optimized structural parameters based on a small dataset. Using the predicted design parameters from this model as the initial condition for 3D optimization, the same optima are reached faster. The effectiveness of this approach is demonstrated in the shape optimization-based inverse design of TE0-TE1 mode converters, an important component in mode-division multiplexing applications. The final optimized designs are identical in both approaches, but leveraging a machine learning-based regression model offers a 35% reduction in computation load for the 3D optimization step. The approach provides a more effective means for sampling larger numbers of 3D optimized designs.
{"title":"Computation cost reduction in 3D shape optimization of nanophotonic components","authors":"Md Mahadi Masnad, Nishat Salsabil, Dan-Xia Xu, Odile Liboiron-Ladouceur, Yuri Grinberg","doi":"10.1088/2040-8986/ad3a76","DOIUrl":"https://doi.org/10.1088/2040-8986/ad3a76","url":null,"abstract":"Inverse design methodologies effectively optimize many design parameters of a photonic device with respect to a primary objective, uncovering locally optimal designs in a typically non-convex parameter space. Often, a variety of secondary objectives (performance metrics) also need to be considered before fabrication takes place. Hence, a large collection of optimized designs is useful, as their performance on secondary objectives often varies. For certain classes of components such as shape-optimized devices, the most efficient optimization approach is to begin with 2D optimization from random parameter initialization and then follow up with 3D re-optimization. Nevertheless, the latter stage is substantially time- and resource-intensive. Thus, obtaining a desired collection of optimized designs through repeated 3D optimizations is a computational challenge. To address this issue, a machine learning-based regression model is proposed to reduce the computation cost involved in the 3D optimization stage. The regression model correlates the 2D and 3D optimized structural parameters based on a small dataset. Using the predicted design parameters from this model as the initial condition for 3D optimization, the same optima are reached faster. The effectiveness of this approach is demonstrated in the shape optimization-based inverse design of TE<sub>0</sub>-TE<sub>1</sub> mode converters, an important component in mode-division multiplexing applications. The final optimized designs are identical in both approaches, but leveraging a machine learning-based regression model offers a 35% reduction in computation load for the 3D optimization step. The approach provides a more effective means for sampling larger numbers of 3D optimized designs.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"5 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140614324","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}
Pub Date : 2024-04-03DOI: 10.1088/2040-8986/ad31cb
Cong Chen, Peng Gao, Yaowei Dai, Xiamin Tong, Jingyuan Gao, Hai Liu
A design scheme combining grating and element additive metasurface is proposed in this paper. Multi-dimensional joint control of the phase, amplitude, angle and polarization and multi-functional integrated metasurface applications were realized by using the inherent characteristics of the light wave properties (polarization and wavelength). Firstly, suitable structural parameters are obtained based on the reflection response of the unit structure, and a 2-bit encoded metasurface array is constructed by utilizing the combinatorial operation between the unit structure. Combined with the polarization selectivity of the lower grating, the dual-function integration of asymmetric transmission (the contrast ratio is 98%) and abnormal reflections (operating bandwidth is 300 nm) was realized. Next, two new half-wave plates were obtained by addition and rotating the elemental structure, and the polarization conversion efficiency of 95%–97% was achieved thanks to the Fabry–Perot cavity formed by the upper metasurface and lower grating. Finally, encoded metasurface based on the geometric phase principle to achieve 300 nm bandwidth cross-polarized wave deflection characteristics with polarization conversion efficiency close to 100%. Our work combines grating structures with element additive metasurfaces, which solves the problem that element structure needs to be redesigned with the change of function, and also paves the way for the application of multifunctional integrated metasurfaces in optical sensing, optical imaging and other fields.
{"title":"Multifunctional beam modulation based on gratings combined with additive metasurfaces","authors":"Cong Chen, Peng Gao, Yaowei Dai, Xiamin Tong, Jingyuan Gao, Hai Liu","doi":"10.1088/2040-8986/ad31cb","DOIUrl":"https://doi.org/10.1088/2040-8986/ad31cb","url":null,"abstract":"A design scheme combining grating and element additive metasurface is proposed in this paper. Multi-dimensional joint control of the phase, amplitude, angle and polarization and multi-functional integrated metasurface applications were realized by using the inherent characteristics of the light wave properties (polarization and wavelength). Firstly, suitable structural parameters are obtained based on the reflection response of the unit structure, and a 2-bit encoded metasurface array is constructed by utilizing the combinatorial operation between the unit structure. Combined with the polarization selectivity of the lower grating, the dual-function integration of asymmetric transmission (the contrast ratio is 98%) and abnormal reflections (operating bandwidth is 300 nm) was realized. Next, two new half-wave plates were obtained by addition and rotating the elemental structure, and the polarization conversion efficiency of 95%–97% was achieved thanks to the Fabry–Perot cavity formed by the upper metasurface and lower grating. Finally, encoded metasurface based on the geometric phase principle to achieve 300 nm bandwidth cross-polarized wave deflection characteristics with polarization conversion efficiency close to 100%. Our work combines grating structures with element additive metasurfaces, which solves the problem that element structure needs to be redesigned with the change of function, and also paves the way for the application of multifunctional integrated metasurfaces in optical sensing, optical imaging and other fields.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"34 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140569153","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}
Pub Date : 2024-03-14DOI: 10.1088/2040-8986/ad2d36
Ting Chen, Zhaoyang Shen, Han Liu
The rapid development of the 5 G technology can be attributed to its outstanding penetration in the low frequency bands ranging from 600 MHz to 6 GHz, particularly in specific frequency ranges like 700 MHz, 2.3 GHz, and 3.5 GHz. Simultaneously, the technology excels in the millimeter-wave spectrum, spanning from 24 GHz to 52 GHz, notably in bands such as 24.25–27.5 GHz and 37–40 GHz, showcasing impressive capabilities for high-speed data transmission. Nevertheless, these signals frequently encounter electromagnetic interference from electronic equipment in practical applications, which compromise the quality of communication. To address these issues, this paper presents the design, fabrication, and measure of a dual-broadband ultra-thin water-based metasurface absorber (WBMA). The unit cell is composed of a 4 mm thick photoresist shell encasing a water layer and metal plate, and features an irregular octagonal prism and a rectangular annulus cavity within the water layer. Simulation and experimental outcomes indicate that the proposed metasurface achieves near-perfect absorption at frequencies from 4.2 GHz to 4.8 GHz and from 23.6 GHz to 51.1 GHz in the transverse electric mode. Additionally, the proposed metasurface exhibits more than 90% absorption in the transverse magnetic mode for frequency ranges from 4.3 GHz to 4.9 GHz and from 23.2 GHz to 50.8 GHz. The designed water-based metasurface also exhibits features of polarization insensitivity and capability to handle wide-angle incidence. Analysis of the electric and magnetic field distribution within the metasurface suggests that the absorption mechanism is driven by strong magnetic resonance within the water layer’s structure. Furthermore, the effective impedance of the metamaterial absorber is explored. Given the unique absorption frequency bands, the proposed WBMA has potential applications in the realm of 5G communication.
{"title":"Ultra-thin water-based metasurface with dual-broadband perfect absorption","authors":"Ting Chen, Zhaoyang Shen, Han Liu","doi":"10.1088/2040-8986/ad2d36","DOIUrl":"https://doi.org/10.1088/2040-8986/ad2d36","url":null,"abstract":"The rapid development of the 5 G technology can be attributed to its outstanding penetration in the low frequency bands ranging from 600 MHz to 6 GHz, particularly in specific frequency ranges like 700 MHz, 2.3 GHz, and 3.5 GHz. Simultaneously, the technology excels in the millimeter-wave spectrum, spanning from 24 GHz to 52 GHz, notably in bands such as 24.25–27.5 GHz and 37–40 GHz, showcasing impressive capabilities for high-speed data transmission. Nevertheless, these signals frequently encounter electromagnetic interference from electronic equipment in practical applications, which compromise the quality of communication. To address these issues, this paper presents the design, fabrication, and measure of a dual-broadband ultra-thin water-based metasurface absorber (WBMA). The unit cell is composed of a 4 mm thick photoresist shell encasing a water layer and metal plate, and features an irregular octagonal prism and a rectangular annulus cavity within the water layer. Simulation and experimental outcomes indicate that the proposed metasurface achieves near-perfect absorption at frequencies from 4.2 GHz to 4.8 GHz and from 23.6 GHz to 51.1 GHz in the transverse electric mode. Additionally, the proposed metasurface exhibits more than 90% absorption in the transverse magnetic mode for frequency ranges from 4.3 GHz to 4.9 GHz and from 23.2 GHz to 50.8 GHz. The designed water-based metasurface also exhibits features of polarization insensitivity and capability to handle wide-angle incidence. Analysis of the electric and magnetic field distribution within the metasurface suggests that the absorption mechanism is driven by strong magnetic resonance within the water layer’s structure. Furthermore, the effective impedance of the metamaterial absorber is explored. Given the unique absorption frequency bands, the proposed WBMA has potential applications in the realm of 5G communication.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"29 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140313730","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}
A water-injected liquid lens is fabricated to tune its focal length using the change in water salinity. It is found that when the salinity of water is changed from zero to 34.25%, the focal length can be changed by about 12.6 mm from 73.7 mm to 86.3 mm. A focal length resolution of approximately 0.75 × 10−2 mm and high temporal stability over a long period have been achieved for the lens foci. This lens is then used to modify the z-scan technique where the lens and the sample both remain fixed without displacement. The performance of the fabricated lens is evaluated by nonlinear refractive index measurement of a sample containing 10.82-pH-synthesized Silver nanoparticles suspended in water with 15 mM of concentration. For verification of the results, a nonlinear refractive index of (−10.6 ± 1.0) × 10−7 cm2 W−1 is firstly measured for the sample using a classical z-scan benefiting from a conventional focal-fixed lens. Interestingly, we found out that when the fabricated lens is replaced in the modified z-scan, the nonlinear refractive index of about (−8.1 ± 0.2) × 10−7 cm2 W−1 can be measured, indicating a similarity in the order and small difference in the coefficient compared to the classical z-scan. This outcome highlights the potential capability and simplicity of the fabricated lens in the modification of the classical z-scan technique.
我们制作了一个注水液体透镜，利用水盐度的变化来调整其焦距。研究发现，当水的盐度从零变为 34.25% 时，焦距可从 73.7 毫米变为 86.3 毫米，变化幅度约为 12.6 毫米。透镜焦点的焦距分辨率约为 0.75 × 10-2 毫米，并且在较长时间内具有较高的时间稳定性。这种透镜随后被用于修改 Z 扫描技术，在这种技术中，透镜和样品都保持固定，不会发生位移。通过对悬浮在 15 mM 浓度水中、含有 10.82-pH 合成银纳米粒子的样品进行非线性折射率测量，评估了所制造透镜的性能。为了验证结果，首先使用传统的固定焦距透镜进行经典 Z 扫描，测量出样品的非线性折射率为 (-10.6 ± 1.0) × 10-7 cm2 W-1。有趣的是，我们发现当在改进型 Z 扫描中替换制作的透镜时，可以测量到约 (-8.1 ± 0.2) × 10-7 cm2 W-1 的非线性折射率，这表明与经典 Z 扫描相比，阶次相似，系数差异较小。这一结果凸显了制作的透镜在改进经典 Z 扫描技术方面的潜在能力和简易性。
{"title":"Effect of water salinity on the focal tuning of an injected liquid lens used to modify the z-scan method","authors":"Yeganeh Shahsavand, Safoura Karimarji, Alireza Khorsandi","doi":"10.1088/2040-8986/ad2edb","DOIUrl":"https://doi.org/10.1088/2040-8986/ad2edb","url":null,"abstract":"A water-injected liquid lens is fabricated to tune its focal length using the change in water salinity. It is found that when the salinity of water is changed from zero to 34.25%, the focal length can be changed by about 12.6 mm from 73.7 mm to 86.3 mm. A focal length resolution of approximately 0.75 × 10<sup>−2</sup> mm and high temporal stability over a long period have been achieved for the lens foci. This lens is then used to modify the <italic toggle=\"yes\">z</italic>-scan technique where the lens and the sample both remain fixed without displacement. The performance of the fabricated lens is evaluated by nonlinear refractive index measurement of a sample containing 10.82-pH-synthesized Silver nanoparticles suspended in water with 15 mM of concentration. For verification of the results, a nonlinear refractive index of (−10.6 ± 1.0) × 10<sup>−7</sup> cm<sup>2</sup> W<sup>−1</sup> is firstly measured for the sample using a classical <italic toggle=\"yes\">z</italic>-scan benefiting from a conventional focal-fixed lens. Interestingly, we found out that when the fabricated lens is replaced in the modified <italic toggle=\"yes\">z</italic>-scan, the nonlinear refractive index of about (−8.1 ± 0.2) × 10<sup>−7</sup> cm<sup>2</sup> W<sup>−1</sup> can be measured, indicating a similarity in the order and small difference in the coefficient compared to the classical <italic toggle=\"yes\">z</italic>-scan. This outcome highlights the potential capability and simplicity of the fabricated lens in the modification of the classical <italic toggle=\"yes\">z</italic>-scan technique.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"44 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140313731","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}
A dual-shot technique based on the field basis addition of two statistically independent speckle patterns is developed to recover an input polarization through a scattering layer. It is proposed theoretically, and demonstrated both numerically and experimentally that by tuning the linear polarization orientation of the reference speckle pattern to 0° and 45° w.r.t. the x-axis, polarization retrieval of an object beam through a scattering layer can be achieved by measuring the degree of polarization of the superposed speckle pattern. The proposed technique can have a wide range of applications in polarization sensing and biomedical imaging.
我们开发了一种基于两个统计上独立的斑点图案的场基相加的双镜头技术，用于通过散射层恢复输入极化。该技术从理论上提出，并通过数值和实验证明，通过将参考斑点图案的线性偏振方向调整为相对于 x 轴的 0° 和 45°，可以通过测量叠加斑点图案的偏振程度来实现穿过散射层的物体光束的偏振恢复。该技术可广泛应用于偏振传感和生物医学成像领域。
{"title":"Dual-shot approach for polarization retrieval through a scattering medium","authors":"Abhijit Roy, Reajmina Parvin, Ankita Karmakar, Abhishek Mandal, Rakesh Kumar Singh, Maruthi M Brundavanam","doi":"10.1088/2040-8986/ad2ed9","DOIUrl":"https://doi.org/10.1088/2040-8986/ad2ed9","url":null,"abstract":"A dual-shot technique based on the field basis addition of two statistically independent speckle patterns is developed to recover an input polarization through a scattering layer. It is proposed theoretically, and demonstrated both numerically and experimentally that by tuning the linear polarization orientation of the reference speckle pattern to 0° and 45° w.r.t. the <italic toggle=\"yes\">x</italic>-axis, polarization retrieval of an object beam through a scattering layer can be achieved by measuring the degree of polarization of the superposed speckle pattern. The proposed technique can have a wide range of applications in polarization sensing and biomedical imaging.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"70 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140313955","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}
Pub Date : 2024-03-12DOI: 10.1088/2040-8986/ad2e1f
Tlek Tapani, Haifeng Lin, Aitor De Andres, Spencer W Jolly, Hinduja Bhuvanendran, Nicolò Maccaferri
We use a vortex retarder-based approach to generate few optical cycles light pulses carrying orbital angular momentum (OAM) (known also as twisted light or optical vortex) from a Yb:KGW oscillator pumping a noncollinear optical parametric amplifier generating sub-10 fs linearly polarized light pulses in the near infrared spectral range (central wavelength 850 nm). We characterize such vortices both spatially and temporally by using astigmatic imaging technique and second harmonic generation-based frequency resolved optical gating, respectively. The generation of optical vortices is analyzed, and its structure reconstructed by estimating the spatio-spectral field and Fourier transforming it into the temporal domain. As a proof of concept, we show that we can also generate sub-20 fs light pulses carrying OAM and with arbitrary polarization on the first-order Poincaré sphere.
{"title":"Vortex plate retarder-based approach for the generation of sub-20 fs light pulses carrying orbital angular momentum","authors":"Tlek Tapani, Haifeng Lin, Aitor De Andres, Spencer W Jolly, Hinduja Bhuvanendran, Nicolò Maccaferri","doi":"10.1088/2040-8986/ad2e1f","DOIUrl":"https://doi.org/10.1088/2040-8986/ad2e1f","url":null,"abstract":"We use a vortex retarder-based approach to generate few optical cycles light pulses carrying orbital angular momentum (OAM) (known also as twisted light or optical vortex) from a Yb:KGW oscillator pumping a noncollinear optical parametric amplifier generating sub-10 fs linearly polarized light pulses in the near infrared spectral range (central wavelength 850 nm). We characterize such vortices both spatially and temporally by using astigmatic imaging technique and second harmonic generation-based frequency resolved optical gating, respectively. The generation of optical vortices is analyzed, and its structure reconstructed by estimating the spatio-spectral field and Fourier transforming it into the temporal domain. As a proof of concept, we show that we can also generate sub-20 fs light pulses carrying OAM and with arbitrary polarization on the first-order Poincaré sphere.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"33 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140314063","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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