{"title":"Analytical solution to second-harmonic generation of ultrashort laser pulse","authors":"Yufei Peng, Chenyang Hu, Lihong Hong, Zhiyuan Li","doi":"10.1088/2040-8986/ad3b17","DOIUrl":"https://doi.org/10.1088/2040-8986/ad3b17","url":null,"abstract":"We present an analytical method to evaluate the second-harmonic generation (SHG) process of ultrashort laser pulses in a nonlinear medium within the small-signal regime. Building upon the broadband nonlinear coupled wave theory, we derive an analytical solution that allows one to investigate the fundamental physics and detailed dynamics of the nonlinear interaction between ultrashort laser pulses. We find that SHG for ultrashort laser pulses in a nonlinear crystal arises from a series of self-SHG and self sum-frequency generation processes involving different frequency components. We have applied the analytical method to investigate specific pulse profiles with Gaussian and sech functions and found good agreement between analytical theory and numerical simulations, validating the accuracy of the analytical approach. The analytical method enables one to explore the evolution of the second-harmonic wave under various pulse profiles, pulse widths, and crystal thicknesses, and offers a more efficient and insightful approach to study the nonlinear optical dynamics of ultrashort laser pulses.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"49 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140608946","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}
Resmi M, Elaganuru Bashaiah and Ramachandrarao Yalla
{"title":"Channeling of fluorescence photons from quantum dots into guided modes of an optical nanofiber tip","authors":"Resmi M, Elaganuru Bashaiah and Ramachandrarao Yalla","doi":"10.1088/2040-8986/ad3ccb","DOIUrl":"https://doi.org/10.1088/2040-8986/ad3ccb","url":null,"abstract":"We demonstrate the channeling of fluorescence photons from quantum dots (QDs) into guided modes of an optical nanofiber tip (ONFT). We deposit QDs on the ONFT using micro/nano fluidic technology. We measure the photon-counting and emission spectrum of fluorescence photons that are channeled into guided modes of the ONFT. The measured emission spectrum confirms the deposition of QDs on the ONFT. We perform numerical simulations to determine channeling efficiency (η) for the ONFT and a single dipole source (SDS) system. For the radially oriented SDS at the center of the facet of the ONFT, we found the maximum η-value of 44% at the fiber size parameter of 7.16, corresponding to the ONFT radius of 0.71 µm for the emission wavelength at 620 nm. Additionally, we investigate the SDS position dependence in transverse directions on the facet of the ONFT in view of keeping experimental ambiguities. The present fiber inline platform may open new avenues in quantum technologies.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"48 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140800974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Enhanced circular dichroism of an X-shaped nanostructure by asymmetric surface plasmon interference","authors":"Abduweli Abdukerim, Haximjan Abdusattar","doi":"10.1088/2040-8986/ad3b15","DOIUrl":"https://doi.org/10.1088/2040-8986/ad3b15","url":null,"abstract":"A plasmonic chiral structure, which is a nanostructure composed of noble metals that lacks planar symmetry, demonstrates significant potential for various applications in bio-sensing, optical forces, switching and controlling the photoluminescence, and detecting chiral light. Understanding its fundamental property of circular dichroism (CD) is critical for these applications. Although the surface plasmon resonance (SPR) mode at a specific moment can explain the CD properties of chiral structures, to gain a better understanding of chirality, the mode shape of the SPR on a nanostructure must be analyzed throughout an entire period. Our study proposes an X-shaped nanostructure to investigate the temporal evolution of plasmon resonance in chiral structures. The simulation results demonstrated that our structure exhibited a significant temporal evolution in plasmonic oscillations, providing new insights into the nature of chirality. In addition, we provided a comprehensive theoretical explanation of CD using the Born–Kuhn model. Furthermore, we discovered that the CD in the X-shaped structure was intensified by the asymmetric interference between the structure and underlying gold film substrate.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"57 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140608781","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}
Haomai Lei, Bin Luo, Jianfei Hu, Jiming Wang, Tong Wu, Youwen Liu
{"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}
Longfei Yin, Tiantian Liu, Xinlong Mai, Shilun Sun, Pengqi Yin, Guohua Wu, Bin Luo
{"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}
Kirill Koshelev, Ivan Toftul, Yongsop Hwang, Yuri Kivshar
{"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}
{"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}
{"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}
Cong Chen, Peng Gao, Yaowei Dai, Xiamin Tong, Jingyuan Gao, Hai Liu
{"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}
{"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}