A polarization-dependent silicon nano-antennas metagrating (PSNM) is proposed for parallel polarization transformation by engineering diffraction orders, upon which a compact Mueller microscopy system is implemented for subtissue-level polarization extraction. The polarization-dependent metagrating is designed using matrix Fourier optics and nonlinear optimization with four diffraction orders described by waveplate-like Jones matrices, which is encoded by nano-antennas combining geometric and propagation phases. The measured phase delay and orientation of each diffraction order of the metagrating deviate by less than 6.7 % from the design values, and the overall diffraction efficiency reaches 70.89 % with a coefficient of variation of 0.021. A transmissive PSNM Mueller microscopy system is developed by directly embedding the metagrating into an infinity-corrected microscopic optical path, which extracts subtissue-level polarization distributions of biological sections over a 152 μm × 152 μm field of view with reduced measurement redundancy, facilitating the differentiation and staging of pathological tissues for potential stain-free diagnostic applications.
{"title":"Diffraction order-engineered polarization-dependent silicon nano-antennas metagrating for compact subtissue Mueller microscopy","authors":"Qingyuan Li, Jianyao Li, Gaodi Chen, Zhiguang Lin, Dongmei Lu, Xiaoxu Deng","doi":"10.1515/nanoph-2025-0405","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0405","url":null,"abstract":"A polarization-dependent silicon nano-antennas metagrating (PSNM) is proposed for parallel polarization transformation by engineering diffraction orders, upon which a compact Mueller microscopy system is implemented for subtissue-level polarization extraction. The polarization-dependent metagrating is designed using matrix Fourier optics and nonlinear optimization with four diffraction orders described by waveplate-like Jones matrices, which is encoded by nano-antennas combining geometric and propagation phases. The measured phase delay and orientation of each diffraction order of the metagrating deviate by less than 6.7 % from the design values, and the overall diffraction efficiency reaches 70.89 % with a coefficient of variation of 0.021. A transmissive PSNM Mueller microscopy system is developed by directly embedding the metagrating into an infinity-corrected microscopic optical path, which extracts subtissue-level polarization distributions of biological sections over a 152 μm × 152 μm field of view with reduced measurement redundancy, facilitating the differentiation and staging of pathological tissues for potential stain-free diagnostic applications.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"15 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145657454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-12-03DOI: 10.1515/nanoph-2025-0437
Raphael Gherman, Sacha Schwarz, Jean-François Bryche, Guillaume Beaudin, Alex Currie, Pierre Levesque, François Fillion-Gourdeau, Steve G. MacLean, Dominique Drouin, Serge Ecoffey, Paul G. Charette
Hybrid plasmonic systems that combine localized and propagative surface plasmons offer new opportunities for tunable light–matter interactions at the nanoscale. This paper provides the most comprehensive study to date of hybridization between gap localized surface plasmons (gap LSP) and diffraction-mediated propagative surface plasmon polaritons (SPP) in arrays of gold nanodisks over a mirror, part of the larger class of nanoparticle-over-mirror (NPoM) devices. By systematically mapping the hybrid mode dispersion as a function of array geometry over a large parameter space, we extract the coupling strength via a coupled oscillator model and reveal its dependence on key structural parameters, with gap thickness identified as the primary tuning factor. The resulting hybrid modes enhance the optical quality factor by nearly fivefold compared to classical LSP while maintaining strong near-field confinement, combining the advantages of their constituent modes. Dephasing times were measured with interferometric time-resolved photoemission electron microscopy (ITR-PEEM). Using a scalable lithography-compatible NPoM architecture that minimizes the optical index mismatch between the dielectric between the nanodisks and the gap material (Al 2 O 3 ), we achieved the highest coupling strength (123 meV) and dephasing time range (23–50 fs) to date in NPoM arrays.
{"title":"A comprehensive study of plasmonic mode hybridization in gold nanoparticle-over-mirror (NPoM) arrays","authors":"Raphael Gherman, Sacha Schwarz, Jean-François Bryche, Guillaume Beaudin, Alex Currie, Pierre Levesque, François Fillion-Gourdeau, Steve G. MacLean, Dominique Drouin, Serge Ecoffey, Paul G. Charette","doi":"10.1515/nanoph-2025-0437","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0437","url":null,"abstract":"Hybrid plasmonic systems that combine localized and propagative surface plasmons offer new opportunities for tunable light–matter interactions at the nanoscale. This paper provides the most comprehensive study to date of hybridization between gap localized surface plasmons (gap LSP) and diffraction-mediated propagative surface plasmon polaritons (SPP) in arrays of gold nanodisks over a mirror, part of the larger class of nanoparticle-over-mirror (NPoM) devices. By systematically mapping the hybrid mode dispersion as a function of array geometry over a large parameter space, we extract the coupling strength via a coupled oscillator model and reveal its dependence on key structural parameters, with gap thickness identified as the primary tuning factor. The resulting hybrid modes enhance the optical quality factor by nearly fivefold compared to classical LSP while maintaining strong near-field confinement, combining the advantages of their constituent modes. Dephasing times were measured with interferometric time-resolved photoemission electron microscopy (ITR-PEEM). Using a scalable lithography-compatible NPoM architecture that minimizes the optical index mismatch between the dielectric between the nanodisks and the gap material (Al <jats:sub>2</jats:sub> O <jats:sub>3</jats:sub> ), we achieved the highest coupling strength (123 meV) and dephasing time range (23–50 fs) to date in NPoM arrays.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"28 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145658191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-12-01DOI: 10.1515/nanoph-2025-0494
Yiyi Li, Wangzhe Zhou, Yuqing Zhang, Xiaoyan Huang, Yutai Chen, Man Yuan, Junbo Yang
Bright-field and phase-contrast imaging represent two of the most essential modes for target recognition and feature extraction, offering broad applicability in fields such as biomedicine and autonomous driving. In this work, we propose a cascaded Moiré metasurfaces system with a large interlayer spacing, which enables switchable bright-field and phase-contrast imaging at a wavelength of 532 nm by adjusting the illumination conditions between coherent and incoherent light sources. By employing an optimized phase-iterative algorithm, the stringent spacing requirement of conventional cascaded Moiré metasurfaces is relaxed from the subwavelength scale (∼100 nm) to beyond 1 mm, while maintaining robust imaging performance under spacing deviations of ±0.1 mm. Through controlled relative rotation of the two metasurfaces by an angle θ , the system dynamically switches between a focused solid Airy disk ( θ = 0°) and vortex beams with tunable topological charges ranging from −5 to +5 ( θ = ±20° to ±100°). The design achieves a focusing efficiency of 82 % and vortex beam purities up to 99 %. Owing to its versatile switching capability, the system supports multi-order edge extraction for both phase-type and amplitude-type objects, reaching a spatial frequency of 228 lp/mm. This approach overcomes the limitation of existing edge-detection metasurfaces, which operate only under either coherent or incoherent illumination. Our findings provide a new technical pathway toward compact, multifunctional, and integrated imaging devices.
{"title":"Large-gap cascaded Moiré metasurfaces enabling switchable bright-field and phase-contrast imaging compatible with coherent and incoherent light","authors":"Yiyi Li, Wangzhe Zhou, Yuqing Zhang, Xiaoyan Huang, Yutai Chen, Man Yuan, Junbo Yang","doi":"10.1515/nanoph-2025-0494","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0494","url":null,"abstract":"Bright-field and phase-contrast imaging represent two of the most essential modes for target recognition and feature extraction, offering broad applicability in fields such as biomedicine and autonomous driving. In this work, we propose a cascaded Moiré metasurfaces system with a large interlayer spacing, which enables switchable bright-field and phase-contrast imaging at a wavelength of 532 nm by adjusting the illumination conditions between coherent and incoherent light sources. By employing an optimized phase-iterative algorithm, the stringent spacing requirement of conventional cascaded Moiré metasurfaces is relaxed from the subwavelength scale (∼100 nm) to beyond 1 mm, while maintaining robust imaging performance under spacing deviations of ±0.1 mm. Through controlled relative rotation of the two metasurfaces by an angle <jats:italic>θ</jats:italic> , the system dynamically switches between a focused solid Airy disk ( <jats:italic>θ</jats:italic> = 0°) and vortex beams with tunable topological charges ranging from −5 to +5 ( <jats:italic>θ</jats:italic> = ±20° to ±100°). The design achieves a focusing efficiency of 82 % and vortex beam purities up to 99 %. Owing to its versatile switching capability, the system supports multi-order edge extraction for both phase-type and amplitude-type objects, reaching a spatial frequency of 228 lp/mm. This approach overcomes the limitation of existing edge-detection metasurfaces, which operate only under either coherent or incoherent illumination. Our findings provide a new technical pathway toward compact, multifunctional, and integrated imaging devices.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"6 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145645160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Directional illumination is critical for next-generation solid-state lighting. In this study, we demonstrate that flexible nanoantenna stickers enhance photoluminescence (PL) directionality. By integrating YAG:Ce phosphor plates and distributed Bragg reflectors (DBRs), these stickers achieve controlled radiation distribution, advancing the development of compact, high-performance illumination technologies. In addition, these stickers produce a different PL output by simply changing the thickness of the phosphor plate. The output PL intensity is doubled by placing a DBR layer on the bottom of the plate, thereby transmitting blue excitation light while reflecting yellow PL. This study provides a simple and versatile method for tuning PL from phosphor plates. This technique can serve as a fundamental tool for controlling light flow with improved efficiency.
{"title":"Directional enhancement of photoluminescence from phosphor plates with TiO 2 nanoantenna stickers","authors":"Hongjie Gao, Joshua T.Y. Tse, Shunsuke Murai, Katsuhisa Tanaka","doi":"10.1515/nanoph-2025-0419","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0419","url":null,"abstract":"Directional illumination is critical for next-generation solid-state lighting. In this study, we demonstrate that flexible nanoantenna stickers enhance photoluminescence (PL) directionality. By integrating YAG:Ce phosphor plates and distributed Bragg reflectors (DBRs), these stickers achieve controlled radiation distribution, advancing the development of compact, high-performance illumination technologies. In addition, these stickers produce a different PL output by simply changing the thickness of the phosphor plate. The output PL intensity is doubled by placing a DBR layer on the bottom of the plate, thereby transmitting blue excitation light while reflecting yellow PL. This study provides a simple and versatile method for tuning PL from phosphor plates. This technique can serve as a fundamental tool for controlling light flow with improved efficiency.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"2 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145613431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 rapid advancement of multimode photonic technologies, optical computing, and quantum circuits, leveraging higher-order modes, necessitates the development of on-chip multiple mode-order converters (MMOCs). However, existing schemes face limitations in traffic capacity, polarization-dependence, and scalability. Herein, we propose a novel highly scalable MMOC design framework enabled by subwavelength grating (SWG) metastructures. By integrating SWG arrays into a taper-tailored multimode waveguide, the design synergizes coherent scattering and beam shaping to achieve efficient target-supermode excitations and precise phase controls, simultaneously. In this way, the target MMOC can be realized according to the functional requirements of mode manipulations by optimizing the metastructures. Experimentally fabricated devices exhibit ILs < 1.85 dB and CTs < −12.5 dB across (22 or 50) nm bandwidths, with a polarization-independent quad-mode operation. Notably, the dual-pair mode exchanging MMOC pioneers simultaneous TE 0 ↔TE 2 and TE 1 ↔TE 3 , doubling exchange efficiency over conventional single-pair solutions. Integrated into a direct-access mode add/drop system (DAMAD), TE 0 /TE 1 dual-mode add/drop operations achieve ILs < 4.5 dB and CTs < −15.5 dB across 41 nm bandwidth. Thereupon, clear eye diagrams at 32/64 Gbps operations demonstrate the capability for the high-speed optical communication. The proposed concept offers a novel strategy for on-chip multiple mode manipulations, with transformative potential in higher-order modes based optical communications.
{"title":"Metastructure-enabled scalable multiple mode-order converters: conceptual design and demonstration in direct-access add/drop multiplexing systems","authors":"Zhenzhao Guo, Weike Zhao, Shengbao Wu, Yunfeng Lai, Shuying Cheng, Daoxin Dai","doi":"10.1515/nanoph-2025-0364","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0364","url":null,"abstract":"The rapid advancement of multimode photonic technologies, optical computing, and quantum circuits, leveraging higher-order modes, necessitates the development of on-chip multiple mode-order converters (MMOCs). However, existing schemes face limitations in traffic capacity, polarization-dependence, and scalability. Herein, we propose a novel highly scalable MMOC design framework enabled by subwavelength grating (SWG) metastructures. By integrating SWG arrays into a taper-tailored multimode waveguide, the design synergizes coherent scattering and beam shaping to achieve efficient target-supermode excitations and precise phase controls, simultaneously. In this way, the target MMOC can be realized according to the functional requirements of mode manipulations by optimizing the metastructures. Experimentally fabricated devices exhibit ILs < 1.85 dB and CTs < −12.5 dB across (22 or 50) nm bandwidths, with a polarization-independent quad-mode operation. Notably, the dual-pair mode exchanging MMOC pioneers simultaneous TE <jats:sub>0</jats:sub> ↔TE <jats:sub>2</jats:sub> and TE <jats:sub>1</jats:sub> ↔TE <jats:sub>3</jats:sub> , doubling exchange efficiency over conventional single-pair solutions. Integrated into a direct-access mode add/drop system (DAMAD), TE <jats:sub>0</jats:sub> /TE <jats:sub>1</jats:sub> dual-mode add/drop operations achieve ILs < 4.5 dB and CTs < −15.5 dB across 41 nm bandwidth. Thereupon, clear eye diagrams at 32/64 Gbps operations demonstrate the capability for the high-speed optical communication. The proposed concept offers a novel strategy for on-chip multiple mode manipulations, with transformative potential in higher-order modes based optical communications.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"200 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145613434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Skyrmions, as topologically structured light fields, have attracted considerable attention due to their unique topological properties and potential applications such as optical communication and advanced sensing technologies. However, their longitudinal evolution, as a dimension ripe for exploitation, typically remains uncontrolled and non-deterministic, hindering its in-depth exploration and application scenarios. Here, this paper presents a novel method using dielectric metasurfaces for precisely modeling the longitudinal dynamics evolution of skyrmions. We introduce a new mechanism that allows for the accurate period modulation of skyrmions stokes properties along the propagation direction by controlling the differences in numerical apertures of a zero-order right-circularly polarized beam and a first-order left-circularly polarized beam. Crucially, the evolution period can be arbitrarily designed, and the propagation distance can be expanded by increasing the waist radius of input beams. To validate this approach, we showcase this paradigm through displacement sensing applications, where single-snapshot polarization measurements directly infer absolute position within a compact metasurface-integrated platform, offering a compact and simple alternative to conventional scanning-based approaches for displacement sensing. Our approach advances the understanding of dynamically controlled topological light fields and enables compact devices for precision metrology and optical information technologies.
{"title":"The longitudinal dynamics evolution of optical skyrmions via meta-optics","authors":"Tiantian He, Chang Liu, Wenxuan Tang, Dan Li, Ping Yan, Qiang Liu, Qirong Xiao","doi":"10.1515/nanoph-2025-0436","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0436","url":null,"abstract":"Skyrmions, as topologically structured light fields, have attracted considerable attention due to their unique topological properties and potential applications such as optical communication and advanced sensing technologies. However, their longitudinal evolution, as a dimension ripe for exploitation, typically remains uncontrolled and non-deterministic, hindering its in-depth exploration and application scenarios. Here, this paper presents a novel method using dielectric metasurfaces for precisely modeling the longitudinal dynamics evolution of skyrmions. We introduce a new mechanism that allows for the accurate period modulation of skyrmions stokes properties along the propagation direction by controlling the differences in numerical apertures of a zero-order right-circularly polarized beam and a first-order left-circularly polarized beam. Crucially, the evolution period can be arbitrarily designed, and the propagation distance can be expanded by increasing the waist radius of input beams. To validate this approach, we showcase this paradigm through displacement sensing applications, where single-snapshot polarization measurements directly infer absolute position within a compact metasurface-integrated platform, offering a compact and simple alternative to conventional scanning-based approaches for displacement sensing. Our approach advances the understanding of dynamically controlled topological light fields and enables compact devices for precision metrology and optical information technologies.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"94 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145613437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-11-29DOI: 10.1515/nanoph-2025-0461
Laura Bollmers, Noah Spiegelberg, Michael Rüsing, Christof Eigner, Laura Padberg, Christine Silberhorn
Periodically poled thin-film lithium niobate (TFLN) crystals are the fundamental building block for highly-efficient quantum light sources and frequency converters. The efficiency of these devices is strongly dependent on the interaction length between the light and the nonlinear material, scaling quadratically with this parameter. Nevertheless, the fabrication of long, continuously poled areas in TFLN remains challenging, the length of continuously poled areas rarely exceeds 10 mm. In this work, we demonstrate a significant progress in this field achieving the periodic poling of continuous poled areas of 70 mm length with a 3 μm poling period and a close to 50 % duty cycle. We compare two poling electrode design approaches to fabricate long, continuous poled areas. The first approach involves the poling of a single, continuous 70 mm long electrode. The second utilize a segmented approach including the poling of more than 20 individual sections forming together a 70 mm long poling area with no stitching errors. While the continuous electrode allows for faster fabrication, the segmented approach allows to individually optimize the poling resulting in less duty cycle variation. A detailed analysis of the periodic poling results reveals that the results of both are consistent with previously reported poling outcomes for shorter devices. Thus, we demonstrate wafer-scale periodic poling exceeding chiplet-size without any loss in the periodic poling quality. Our work presents a key step towards highly-efficient, narrow-bandwidth and low-pump power nonlinear optical devices.
{"title":"Segmented finger electrodes to optimize ultra-long continuous wafer-scale periodic poling in thin-film lithium niobate","authors":"Laura Bollmers, Noah Spiegelberg, Michael Rüsing, Christof Eigner, Laura Padberg, Christine Silberhorn","doi":"10.1515/nanoph-2025-0461","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0461","url":null,"abstract":"Periodically poled thin-film lithium niobate (TFLN) crystals are the fundamental building block for highly-efficient quantum light sources and frequency converters. The efficiency of these devices is strongly dependent on the interaction length between the light and the nonlinear material, scaling quadratically with this parameter. Nevertheless, the fabrication of long, continuously poled areas in TFLN remains challenging, the length of continuously poled areas rarely exceeds 10 mm. In this work, we demonstrate a significant progress in this field achieving the periodic poling of continuous poled areas of 70 mm length with a 3 μm poling period and a close to 50 % duty cycle. We compare two poling electrode design approaches to fabricate long, continuous poled areas. The first approach involves the poling of a single, continuous 70 mm long electrode. The second utilize a segmented approach including the poling of more than 20 individual sections forming together a 70 mm long poling area with no stitching errors. While the continuous electrode allows for faster fabrication, the segmented approach allows to individually optimize the poling resulting in less duty cycle variation. A detailed analysis of the periodic poling results reveals that the results of both are consistent with previously reported poling outcomes for shorter devices. Thus, we demonstrate wafer-scale periodic poling exceeding chiplet-size without any loss in the periodic poling quality. Our work presents a key step towards highly-efficient, narrow-bandwidth and low-pump power nonlinear optical devices.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"147 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145613428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-11-28DOI: 10.1515/nanoph-2025-0501
Seunghyun Lee, Byounghyo Lee, Haejun Chung
Waveguide-based augmented-reality (AR) displays offer compact, optical see-through form factors but remain limited by chromatic dispersion, ghosting from parasitic diffraction orders, distortion of the see-through scene, and a restricted eyebox. We present triple-function metasurface couplers designed using adjoint-based optimization, which overcome these limitations and establish computational performance bounds. The out-coupler simultaneously preserves zeroth-order transmission of the see-through path and directs display light into designated diffraction orders while returning residual guided power as zeroth-order reflection for eyebox expansion. The in-coupler assigns distinct diffraction orders to R/G/B and equalizes their in-plane propagation angles, achieving achromatic guidance and eliminating chromatic path divergence. Quantitatively, the optimized out-coupler provides >90 % angle-averaged zeroth-order transmission for the see-through view (10–40× lower higher-order leakage) and >95 % zeroth-order guided reflection, while maintaining efficient diffractive couplings to the eyebox. PSF/MTF analyses confirm near-diffraction-limited virtual-image quality and strong suppression of see-through view distortion. Finally, benchmarking freeform against fabrication-constrained multilayer architectures (1–6 layers) shows that multilayers approach the freeform upper bound while remaining practical to fabricate. These results outline a general, manufacturable methodology for multifunctional metasurface couplers and a practical route to compact, high-quality AR waveguides.
{"title":"Optical see-through augmented reality via inverse-designed waveguide couplers","authors":"Seunghyun Lee, Byounghyo Lee, Haejun Chung","doi":"10.1515/nanoph-2025-0501","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0501","url":null,"abstract":"Waveguide-based augmented-reality (AR) displays offer compact, optical see-through form factors but remain limited by chromatic dispersion, ghosting from parasitic diffraction orders, distortion of the see-through scene, and a restricted eyebox. We present triple-function metasurface couplers designed using adjoint-based optimization, which overcome these limitations and establish computational performance bounds. The out-coupler simultaneously preserves zeroth-order transmission of the see-through path and directs display light into designated diffraction orders while returning residual guided power as zeroth-order reflection for eyebox expansion. The in-coupler assigns distinct diffraction orders to R/G/B and equalizes their in-plane propagation angles, achieving achromatic guidance and eliminating chromatic path divergence. Quantitatively, the optimized out-coupler provides >90 % angle-averaged zeroth-order transmission for the see-through view (10–40× lower higher-order leakage) and >95 % zeroth-order guided reflection, while maintaining efficient diffractive couplings to the eyebox. PSF/MTF analyses confirm near-diffraction-limited virtual-image quality and strong suppression of see-through view distortion. Finally, benchmarking freeform against fabrication-constrained multilayer architectures (1–6 layers) shows that multilayers approach the freeform upper bound while remaining practical to fabricate. These results outline a general, manufacturable methodology for multifunctional metasurface couplers and a practical route to compact, high-quality AR waveguides.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"18 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145611134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-11-28DOI: 10.1515/nanoph-2025-0247
Nikolas Hadjiantoni, Heedong Goh, Stephen M. Hanham, Miguel Navarro-Cía, Andrea Alù
While conventional von Neumann based machines are increasingly challenged by modern day requirements, electromagnetic analog computing devices promise to provide a platform that is highly parallel, efficient and fast. Along this paradigm, it has been shown that arrays of subwavelength electromagnetic scatterers can be used as solvers of partial differential equations. Inverse design offers a powerful tool to synthesize such analog computing machines, utilizing engineered non-local responses to produce the solution of a desired mathematical operation encoded in the scattered fields. So far, this approach has been largely restricted to linear, reciprocal scatterers, limiting its generality and applicability. Here we demonstrate how arrays of gyrotropic scatterers can be used to solve a more general class of differential equations. Through inverse design, with a combination of evolutionary and gradient based algorithms, the position of the scatterers is optimized to achieve the desired kernel response. Introducing gyrotropic media, we also demonstrate improved accuracy by >2 orders of magnitude compared to similarly sized reciprocal systems designed with the same method.
{"title":"Inverse-designed gyrotropic scatterers for non-reciprocal analog computing","authors":"Nikolas Hadjiantoni, Heedong Goh, Stephen M. Hanham, Miguel Navarro-Cía, Andrea Alù","doi":"10.1515/nanoph-2025-0247","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0247","url":null,"abstract":"While conventional von Neumann based machines are increasingly challenged by modern day requirements, electromagnetic analog computing devices promise to provide a platform that is highly parallel, efficient and fast. Along this paradigm, it has been shown that arrays of subwavelength electromagnetic scatterers can be used as solvers of partial differential equations. Inverse design offers a powerful tool to synthesize such analog computing machines, utilizing engineered non-local responses to produce the solution of a desired mathematical operation encoded in the scattered fields. So far, this approach has been largely restricted to linear, reciprocal scatterers, limiting its generality and applicability. Here we demonstrate how arrays of gyrotropic scatterers can be used to solve a more general class of differential equations. Through inverse design, with a combination of evolutionary and gradient based algorithms, the position of the scatterers is optimized to achieve the desired kernel response. Introducing gyrotropic media, we also demonstrate improved accuracy by >2 orders of magnitude compared to similarly sized reciprocal systems designed with the same method.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"29 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145611130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Combining the advantages of polydopamine (PDA), gold nanoparticles (AuNPs), and U-shaped optical fibers, a PDA/AuNPs/PDA sandwich structure modified U-shaped optical fiber surface plasmon resonance (SPR) biosensor was proposed and used for the detection of rabbit IgG. The U-shaped structure significantly enhances the penetration depth of the evanescent field. The PDA/AuNPs/PDA sandwich structure boosts coupling efficiency of SPR and LSPR, increases the specific surface area of the sensor, and improves surface activity. The experimental results show that the refractive index (RI) sensitivity of the sensor is 6,206.32 nm/RIU in the RI range of 1.3353–1.3595, which is 1.63 times higher than the raw U-shaped sensor. The biosensor for detection of rabbit IgG achieved a biosensitivity of 0.153 nm/(ng/mL), which is two orders of magnitude higher and a limit of detection (LOD) of 0.131 ng/mL, which is one order of magnitude lower. The outstanding performance of the proposed biosensor offers a new solution for the detection of low-concentration biological solutions, and it has great potential applications in the field of medical diagnosis.
{"title":"High-sensitivity U-shaped biosensor for rabbit IgG detection based on PDA/AuNPs/PDA sandwich structure","authors":"Pengxiang Chang, Yirui Zhang, Ailing Zhang, Zhen Li, Zhiyang Wang, Yanmei Shi","doi":"10.1515/nanoph-2025-0367","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0367","url":null,"abstract":"Combining the advantages of polydopamine (PDA), gold nanoparticles (AuNPs), and U-shaped optical fibers, a PDA/AuNPs/PDA sandwich structure modified U-shaped optical fiber surface plasmon resonance (SPR) biosensor was proposed and used for the detection of rabbit IgG. The U-shaped structure significantly enhances the penetration depth of the evanescent field. The PDA/AuNPs/PDA sandwich structure boosts coupling efficiency of SPR and LSPR, increases the specific surface area of the sensor, and improves surface activity. The experimental results show that the refractive index (RI) sensitivity of the sensor is 6,206.32 nm/RIU in the RI range of 1.3353–1.3595, which is 1.63 times higher than the raw U-shaped sensor. The biosensor for detection of rabbit IgG achieved a biosensitivity of 0.153 nm/(ng/mL), which is two orders of magnitude higher and a limit of detection (LOD) of 0.131 ng/mL, which is one order of magnitude lower. The outstanding performance of the proposed biosensor offers a new solution for the detection of low-concentration biological solutions, and it has great potential applications in the field of medical diagnosis.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"150 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145611115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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