Moiré metalens is attractive for imaging applications due to their compact form factor and high zoom ratio. Here, we propose a novel Moiré zoom metalens system that achieves a continuous 10× zoom over a focal length range of 2.2–22 mm at 1,064 nm, while extending the full field of view up to 93°. A variable aperture, capable of axial translation, is introduced to jointly suppress aberrations and maintain a large aperture size with f-numbers ranging from 2.5 to 7.5. The system delivers near-diffraction–limited imaging resolution across the entire zoom and field-of-view range, with Strehl ratios exceeding 0.9. This level of performance is comparable to commercial optics and is rarely reported in metalens-based zoom systems. Remarkably, the total optical volume is only ∼4.2 × 32 mm, underscoring its potential for miniaturized imaging. Furthermore, we establish an integrated design and validation pipeline that strategically combines geometric optics, scalar diffraction, and vectorial electromagnetic theory. This multi-theory approach provides an efficient and generalizable pathway for the development of high-performance metalens systems.
{"title":"A 10× continuously zoomable metalens system with super-wide field of view and near-diffraction–limited resolution","authors":"Wangzhe Zhou, Shaoqi Li, Yiyi Li, Zongyuan Chen, Man Yuan, Fen Zhao, Yutai Chen, Huan Chen, Zhaojian Zhang, Jiagui Wu, Junbo Yang","doi":"10.1515/nanoph-2025-0399","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0399","url":null,"abstract":"Moiré metalens is attractive for imaging applications due to their compact form factor and high zoom ratio. Here, we propose a novel Moiré zoom metalens system that achieves a continuous 10× zoom over a focal length range of 2.2–22 mm at 1,064 nm, while extending the full field of view up to 93°. A variable aperture, capable of axial translation, is introduced to jointly suppress aberrations and maintain a large aperture size with f-numbers ranging from 2.5 to 7.5. The system delivers near-diffraction–limited imaging resolution across the entire zoom and field-of-view range, with Strehl ratios exceeding 0.9. This level of performance is comparable to commercial optics and is rarely reported in metalens-based zoom systems. Remarkably, the total optical volume is only ∼4.2 × 32 mm, underscoring its potential for miniaturized imaging. Furthermore, we establish an integrated design and validation pipeline that strategically combines geometric optics, scalar diffraction, and vectorial electromagnetic theory. This multi-theory approach provides an efficient and generalizable pathway for the development of high-performance metalens systems.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"77 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145567131","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 spatiotemporal sculpturing of light beams with arbitrary phase and polarization topologies has garnered significant attention in recent years due to its potential to advance optical technologies and reveal novel physical phenomena. Examples of spatiotemporal beams include space–time wave packets, flying donuts, tilted pulse fronts, X-waves, Airy pulses, and spatiotemporal optical vortices. Here, we introduce and demonstrate a new class of spatiotemporal polarization states of light. We propose a generalized spatiotemporal higher-order Poincaré sphere and show that these polarization states emerge from the superposition of two orthogonal circular polarization states, each carrying a spatiotemporal optical vortex. Such a choice of the basis enables simultaneous control of the spatial and temporal degrees of freedom of light. Theoretical predictions are experimentally validated using ultrafast femtosecond pulses, revealing how the resulting polarization distributions evolve in both space and time. Finally, we further extend this approach to construct a family of spatiotemporal skyrmionic textures that are localized, topologically nontrivial configurations of the electromagnetic field vector, offering a versatile framework for generating and controlling multidimensional (space and time) structured polarization fields. The ability to create and manipulate diverse forms of spatiotemporal skyrmionic textures opens up new opportunities for studying complex light–matter interaction phenomena, advanced imaging and micromanipulation, and encoding information across both space and time, with potential implications for advanced optical communication and information processing in classical and quantum domains.
{"title":"Structuring polarization states of light in space and time","authors":"Danilo Gomes Pires, Jiaren Tan, Hooman Barati Sedeh, Natalia M. Litchinitser","doi":"10.1515/nanoph-2025-0438","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0438","url":null,"abstract":"The spatiotemporal sculpturing of light beams with arbitrary phase and polarization topologies has garnered significant attention in recent years due to its potential to advance optical technologies and reveal novel physical phenomena. Examples of spatiotemporal beams include space–time wave packets, flying donuts, tilted pulse fronts, X-waves, Airy pulses, and spatiotemporal optical vortices. Here, we introduce and demonstrate a new class of spatiotemporal polarization states of light. We propose a generalized spatiotemporal higher-order Poincaré sphere and show that these polarization states emerge from the superposition of two orthogonal circular polarization states, each carrying a spatiotemporal optical vortex. Such a choice of the basis enables simultaneous control of the spatial and temporal degrees of freedom of light. Theoretical predictions are experimentally validated using ultrafast femtosecond pulses, revealing how the resulting polarization distributions evolve in both space and time. Finally, we further extend this approach to construct a family of spatiotemporal skyrmionic textures that are localized, topologically nontrivial configurations of the electromagnetic field vector, offering a versatile framework for generating and controlling multidimensional (space and time) structured polarization fields. The ability to create and manipulate diverse forms of spatiotemporal skyrmionic textures opens up new opportunities for studying complex light–matter interaction phenomena, advanced imaging and micromanipulation, and encoding information across both space and time, with potential implications for advanced optical communication and information processing in classical and quantum domains.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"1 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145553417","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 : 2025-11-20DOI: 10.1515/nanoph-2025-0465
Asma Fallah, Eileen Otte
Due to their unique tight focusing properties, structured light beams, such as cylindrical vector beams, offer unique opportunities for tailoring light–matter interaction at the nanoscale. In this work, we investigate the scattering response of a spherical nanoparticle illuminated by a Focused Generalized Cylindrical Vector Beam (FGCVB). We employ a full vectorial framework – numerically and analytically. We model the focal field distribution of the FGCVB, compute and examine the scattered fields using generalized Lorenz–Mie theory, and analyze the influence of beam polarization structure on the scattering cross section and multipole content of the scattered fields. We find that tailoring the polarization composition of the incident FGCVB allows selective excitation of and tuning between electric and magnetic dipolar as well as quadrupolar modes, which offers a pathway for polarization-controlled light scattering at the nanoscale. We also examine and employ the influence of focal point position and numerical aperture of the lens on the scattered field. This work expands our understanding of vector beam scattering and provides design principles for polarization-resolved nano-optical spectroscopy and microscopy.
{"title":"Structured beam-driven multipolar mode control in nanoparticles","authors":"Asma Fallah, Eileen Otte","doi":"10.1515/nanoph-2025-0465","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0465","url":null,"abstract":"Due to their unique tight focusing properties, structured light beams, such as cylindrical vector beams, offer unique opportunities for tailoring light–matter interaction at the nanoscale. In this work, we investigate the scattering response of a spherical nanoparticle illuminated by a Focused Generalized Cylindrical Vector Beam (FGCVB). We employ a full vectorial framework – numerically and analytically. We model the focal field distribution of the FGCVB, compute and examine the scattered fields using generalized Lorenz–Mie theory, and analyze the influence of beam polarization structure on the scattering cross section and multipole content of the scattered fields. We find that tailoring the polarization composition of the incident FGCVB allows selective excitation of and tuning between electric and magnetic dipolar as well as quadrupolar modes, which offers a pathway for polarization-controlled light scattering at the nanoscale. We also examine and employ the influence of focal point position and numerical aperture of the lens on the scattered field. This work expands our understanding of vector beam scattering and provides design principles for polarization-resolved nano-optical spectroscopy and microscopy.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"37 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145553418","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 : 2025-11-18DOI: 10.1515/nanoph-2025-0448
Tetiana Slipchenko, Jaime Abad-Arredondo, Antonio Consoli, Francisco J. García Vidal, Antonio I. Fernández-Domínguez, Pedro David García, Cefe López
A commercial Fabry–Perot laser diode is characterized by highly disproportionate dimensions, which poses a significant numerical challenge, even for state-of-the-art tools. This challenge is exacerbated when one of the cavity mirrors is roughened, as is the case when fabricating random laser diodes. Such a system involves length scales from several hundred micrometres (length) to a few nanometres (roughness) all of which are relevant when studying optical properties in the visible. While involving an extreme range of dimensions, these cavities cannot be treated through statistical approaches such as those used with self-similar fractal structures known to show well-studied properties. Here we deploy numerical methods to compute cavity modes and show how random corrugations of the Fabry–Perot cavity wall affect statistical proper-ties of their spectral features. Our study constitutes a necessary first step in developing technologically essential devices for photonic computation and efficient speckle-free illumination.
{"title":"Rough Fabry–Perot cavity: a vastly multi-scale numerical problem","authors":"Tetiana Slipchenko, Jaime Abad-Arredondo, Antonio Consoli, Francisco J. García Vidal, Antonio I. Fernández-Domínguez, Pedro David García, Cefe López","doi":"10.1515/nanoph-2025-0448","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0448","url":null,"abstract":"A commercial Fabry–Perot laser diode is characterized by highly disproportionate dimensions, which poses a significant numerical challenge, even for state-of-the-art tools. This challenge is exacerbated when one of the cavity mirrors is roughened, as is the case when fabricating random laser diodes. Such a system involves length scales from several hundred micrometres (length) to a few nanometres (roughness) all of which are relevant when studying optical properties in the visible. While involving an extreme range of dimensions, these cavities cannot be treated through statistical approaches such as those used with self-similar fractal structures known to show well-studied properties. Here we deploy numerical methods to compute cavity modes and show how random corrugations of the Fabry–Perot cavity wall affect statistical proper-ties of their spectral features. Our study constitutes a necessary first step in developing technologically essential devices for photonic computation and efficient speckle-free illumination.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"116 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145536033","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 : 2025-11-18DOI: 10.1515/nanoph-2025-0469
Pietro Tassan, Etsuki Kobiyama, Jan David Fischbach, Dario Ballarini, Luca Moretti, Lorenzo Dominici, Milena De Giorgi, Daniele Sanvitto, Michael Forster, Ullrich Scherf, Antonis Olziersky, Carsten Rockstuhl, Thomas Jebb Sturges, Rainer F. Mahrt, Darius Urbonas, Thilo Stöferle
A central challenge for advancing polariton-based circuits is the controlled and scalable coupling of individual condensates. Existing approaches based on etched or epitaxially grown microcavities are fabrication-intensive and restrict in-plane coupling. To overcome these limitations, we introduce a lithographically defined silicon-based platform of high-contrast grating (HCG) microcavities with a ladder-type π-conjugated polymer. In this system, doublet cavities exhibit mode hybridization into bonding and antibonding states, where coupling is mediated across shared HCG mirrors. Extending the design to arrays, N -coupled condensates exhibit systematic red-shifts of the condensate energy, due to delocalization, and a progressive threshold reduction, consistent with extended binding modes. Our experimental results are quantitatively supported by transition-matrix multi-scattering simulations, together with tight-binding modelling. First-order coherence measurements using Michelson interferometry confirm the existence of spatially extended condensates with exponentially decaying temporal coherence. Altogether, these results establish a scalable route toward integrated polariton devices and quantum photonic networks.
{"title":"Integrated array of coupled exciton–polariton condensates","authors":"Pietro Tassan, Etsuki Kobiyama, Jan David Fischbach, Dario Ballarini, Luca Moretti, Lorenzo Dominici, Milena De Giorgi, Daniele Sanvitto, Michael Forster, Ullrich Scherf, Antonis Olziersky, Carsten Rockstuhl, Thomas Jebb Sturges, Rainer F. Mahrt, Darius Urbonas, Thilo Stöferle","doi":"10.1515/nanoph-2025-0469","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0469","url":null,"abstract":"A central challenge for advancing polariton-based circuits is the controlled and scalable coupling of individual condensates. Existing approaches based on etched or epitaxially grown microcavities are fabrication-intensive and restrict in-plane coupling. To overcome these limitations, we introduce a lithographically defined silicon-based platform of high-contrast grating (HCG) microcavities with a ladder-type π-conjugated polymer. In this system, doublet cavities exhibit mode hybridization into bonding and antibonding states, where coupling is mediated across shared HCG mirrors. Extending the design to arrays, <jats:italic>N</jats:italic> -coupled condensates exhibit systematic red-shifts of the condensate energy, due to delocalization, and a progressive threshold reduction, consistent with extended binding modes. Our experimental results are quantitatively supported by transition-matrix multi-scattering simulations, together with tight-binding modelling. First-order coherence measurements using Michelson interferometry confirm the existence of spatially extended condensates with exponentially decaying temporal coherence. Altogether, these results establish a scalable route toward integrated polariton devices and quantum photonic networks.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"6 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145536445","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 : 2025-11-18DOI: 10.1515/nanoph-2025-0388
Elif Nur Dayi, Omer Can Karaman, Diotime Pellet, Alan R. Bowman, Giulia Tagliabue
Second-harmonic generation (SHG) is a powerful surface-specific probe for centrosymmetric materials, with broad relevance to energy and biological interfaces. Plasmonic nanomaterials have been extensively utilized to amplify this nonlinear response. Yet, material instability has constrained most studies to gold, despite the significance of plasmonic metals such as copper for catalysis. Here, we demonstrate stable and anisotropic SHG from monocrystalline copper, overcoming long-standing challenges associated with surface degradation. By leveraging an on-substrate synthesis approach that yields atomically flat and oxidation-resistant Cu microflakes, we enable reliable SHG measurements and reveal a strong cross-polarized response with C 3 v surface symmetry. The SHG signal remains stable over 3 h of continuous femtosecond excitation, highlighting the remarkable optical robustness of the Cu microflakes. These results reinforce the viability of monocrystalline Cu as a robust platform for nonlinear nanophotonics and surface-sensitive spectroscopy, expanding the range of copper-based optical applications.
{"title":"Cross-polarized and stable second harmonic generation from monocrystalline copper","authors":"Elif Nur Dayi, Omer Can Karaman, Diotime Pellet, Alan R. Bowman, Giulia Tagliabue","doi":"10.1515/nanoph-2025-0388","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0388","url":null,"abstract":"Second-harmonic generation (SHG) is a powerful surface-specific probe for centrosymmetric materials, with broad relevance to energy and biological interfaces. Plasmonic nanomaterials have been extensively utilized to amplify this nonlinear response. Yet, material instability has constrained most studies to gold, despite the significance of plasmonic metals such as copper for catalysis. Here, we demonstrate stable and anisotropic SHG from monocrystalline copper, overcoming long-standing challenges associated with surface degradation. By leveraging an on-substrate synthesis approach that yields atomically flat and oxidation-resistant Cu microflakes, we enable reliable SHG measurements and reveal a strong cross-polarized response with <jats:italic>C</jats:italic> <jats:sub> 3 <jats:italic>v</jats:italic> </jats:sub> surface symmetry. The SHG signal remains stable over 3 h of continuous femtosecond excitation, highlighting the remarkable optical robustness of the Cu microflakes. These results reinforce the viability of monocrystalline Cu as a robust platform for nonlinear nanophotonics and surface-sensitive spectroscopy, expanding the range of copper-based optical applications.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"131 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145536339","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 : 2025-11-18DOI: 10.1515/nanoph-2025-0476
Zijun Huang, Rui Ma, Qiang Ying, Peng Hao, Wei Ke, Xinlun Cai, X. Steve Yao
Integrated optoelectronic oscillators (OEOs) have emerged as pivotal enablers of compact, energy-efficient solutions for generating high-frequency radio-frequency (RF) signals with exceptional spectral purity – an essential demand in the advancement of radar and communication technologies. Yet, the quest for ultra-low phase noise near the carrier remains hampered by laser frequency instability and environmental fluctuations. In this work, we unveil the first photonic-integrated, high-order subharmonic injection-locked OEO realized on a thin-film lithium niobate (TFLN) platform, seamlessly uniting a Mach–Zehnder modulator (MZM) and an add-drop microring resonator (MRR) in a monolithic architecture. By harnessing an external RF source operating at a fractional subharmonic (1/2 N , with N = 1, 3, 5…) of the OEO’s free-running frequency, our system achieves robust locking to the 2 N -th harmonic of the injected signal, made possible through the beating of ± N -th order modulation sidebands – precisely selected by the dual resonances of the MRR – at the photodetector. We experimentally demonstrate the generation of 28.7 GHz signals via second- and sixth-order subharmonic injection locking, employing external RF injections at 14.35 GHz and 4.78 GHz, respectively. This yields an outstanding side-mode suppression ratio (SMSR) exceeding 78 dB and remarkably low spurious emissions. Furthermore, the measured phase noise achieves values below −80 dBc/Hz at 100 Hz and below −115 dBc/Hz at 10 kHz offsets from the 28.7 GHz carrier, delineating a new standard for integrated OEO performance.
集成光电振荡器（OEOs）已经成为紧凑，节能的解决方案的关键推动者，用于产生具有特殊频谱纯度的高频射频（RF）信号-这是雷达和通信技术进步的基本需求。然而，对载波附近超低相位噪声的追求仍然受到激光频率不稳定性和环境波动的阻碍。在这项工作中，我们推出了第一个在薄膜铌酸锂（TFLN）平台上实现的光子集成、高阶次谐波注入锁定OEO，将马赫-曾德尔调制器（MZM）和加滴微环谐振器（MRR）无缝地结合在一个单片架构中。通过利用在OEO自由运行频率的分数次谐波（1/2 N, N = 1,3,5…）下工作的外部射频源，我们的系统实现了对注入信号的2 N次谐波的鲁棒锁定，这是通过在光电探测器上敲打±N阶调制边带（由MRR的双共振精确选择）来实现的。通过实验证明，采用14.35 GHz和4.78 GHz的外部射频注入，通过二阶和六阶亚谐波注入锁定产生28.7 GHz信号。这产生了出色的侧模抑制比（SMSR）超过78 dB和非常低的杂散发射。此外，测得的相位噪声在100hz时低于- 80 dBc/Hz，在28.7 GHz载波的10 kHz偏移时低于- 115 dBc/Hz，描绘了集成OEO性能的新标准。
{"title":"Subharmonic injection-locked photonic integrated thin-film lithium niobate optoelectronic oscillator","authors":"Zijun Huang, Rui Ma, Qiang Ying, Peng Hao, Wei Ke, Xinlun Cai, X. Steve Yao","doi":"10.1515/nanoph-2025-0476","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0476","url":null,"abstract":"Integrated optoelectronic oscillators (OEOs) have emerged as pivotal enablers of compact, energy-efficient solutions for generating high-frequency radio-frequency (RF) signals with exceptional spectral purity – an essential demand in the advancement of radar and communication technologies. Yet, the quest for ultra-low phase noise near the carrier remains hampered by laser frequency instability and environmental fluctuations. In this work, we unveil the first photonic-integrated, high-order subharmonic injection-locked OEO realized on a thin-film lithium niobate (TFLN) platform, seamlessly uniting a Mach–Zehnder modulator (MZM) and an add-drop microring resonator (MRR) in a monolithic architecture. By harnessing an external RF source operating at a fractional subharmonic (1/2 <jats:italic>N</jats:italic> , with <jats:italic>N</jats:italic> = 1, 3, 5…) of the OEO’s free-running frequency, our system achieves robust locking to the 2 <jats:italic>N</jats:italic> -th harmonic of the injected signal, made possible through the beating of ± <jats:italic>N</jats:italic> -th order modulation sidebands – precisely selected by the dual resonances of the MRR – at the photodetector. We experimentally demonstrate the generation of 28.7 GHz signals via second- and sixth-order subharmonic injection locking, employing external RF injections at 14.35 GHz and 4.78 GHz, respectively. This yields an outstanding side-mode suppression ratio (SMSR) exceeding 78 dB and remarkably low spurious emissions. Furthermore, the measured phase noise achieves values below −80 dBc/Hz at 100 Hz and below −115 dBc/Hz at 10 kHz offsets from the 28.7 GHz carrier, delineating a new standard for integrated OEO performance.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"122 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145536391","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}
Thin-film lithium niobate (TFLN) has emerged as a powerful platform for integrated nonlinear optics owing to its large χ(2) nonlinearity, tight confinement and flexible tunability. To fully excavate such superior nonlinear optical properties, domain engineering is commonly adopted to fulfill the phase matching condition of χ(2) processes. During the past decade, various domain engineered TFLN nonlinear optical devices have been demonstrated, showing extremely high length-normalized nonlinear optical conversion efficiencies. However, application-driven scenarios demand absolute energy conversion in nonlinear frequency conversion rather than length-normalized efficiencies, but the progress has been limited by imperfect fabrication processes. In this work, we realize effective on-chip nonlinear energy conversion by developing low-loss and high-quality domain engineered TFLN waveguides with long interaction length. Ion beam trimming (IBT) technique and an etching-prior-poling workflow are adopted for such fabrication. Optical characterization yields an overall second-harmonic generation (SHG) efficiency of 2,590 %/W. A high pump depletion of 85.7 % is demonstrated under continuous-wave operation, which directly reflects strong nonlinear energy conversion. These results may lead to breakthroughs in applications like classical optical frequency conversion, quantum frequency conversion, and quantum light generation.
{"title":"High pump depletion second-harmonic generation using domain engineered thin-film lithium niobate waveguides","authors":"Chenyu Wang, Mengwen Chen, Xiao-Hui Tian, Zishuo Gu, Jie Tang, Yong Zhang, Zikang Wang, Kunpeng Jia, Chenyang Shi, Xiaowen Gu, Guang Qian, Zhenlin Wang, Shi-Ning Zhu, Zhenda Xie","doi":"10.1515/nanoph-2025-0505","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0505","url":null,"abstract":"Thin-film lithium niobate (TFLN) has emerged as a powerful platform for integrated nonlinear optics owing to its large <jats:italic>χ</jats:italic> <jats:sup>(2)</jats:sup> nonlinearity, tight confinement and flexible tunability. To fully excavate such superior nonlinear optical properties, domain engineering is commonly adopted to fulfill the phase matching condition of <jats:italic>χ</jats:italic> <jats:sup>(2)</jats:sup> processes. During the past decade, various domain engineered TFLN nonlinear optical devices have been demonstrated, showing extremely high length-normalized nonlinear optical conversion efficiencies. However, application-driven scenarios demand absolute energy conversion in nonlinear frequency conversion rather than length-normalized efficiencies, but the progress has been limited by imperfect fabrication processes. In this work, we realize effective on-chip nonlinear energy conversion by developing low-loss and high-quality domain engineered TFLN waveguides with long interaction length. Ion beam trimming (IBT) technique and an etching-prior-poling workflow are adopted for such fabrication. Optical characterization yields an overall second-harmonic generation (SHG) efficiency of 2,590 %/W. A high pump depletion of 85.7 % is demonstrated under continuous-wave operation, which directly reflects strong nonlinear energy conversion. These results may lead to breakthroughs in applications like classical optical frequency conversion, quantum frequency conversion, and quantum light generation.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"7 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145536096","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}
To address the critical limitations of conventional band-switching technologies – such as their slow speed, high energy consumption, and mechanical instability – this research introduces a novel deep-learning-driven framework for the intelligent inverse design of polarization-multiplexed metasurfaces. This approach represents a paradigm shift from traditional methods by enabling single-step, computational discovery of metasurface designs that directly encode two distinct optical functions within a single flat device. At the heart of our framework is a custom-designed deep neural network that seamlessly integrates parallel convolutional layers for robust feature extraction with cascaded regression modules for high-precision prediction. This hybrid architecture allows us to engineer sub-wavelength meta-atoms to achieve desired optical responses rigorously. As a groundbreaking demonstration, we designed and optimized a metasurface that achieves dynamic band switching solely through polarization modulation: it generates a targeted transmission peak in the O-band (1,260–1,360 nm) under y -polarization and an independent peak in the C-band (1,530–1,565 nm) under x -polarization. This mechanism eliminates the need for moving parts. The resulting device exhibits a switching efficiency orders of magnitude greater than its mechanical counterparts, while simultaneously offering enhanced stability, lower power consumption, and inherent adaptability for reconfigurable optical networks. Our work not only validates a specific device but also establishes a robust and generalizable design paradigm, underscoring the transformative potential of uniting deep learning with metasurfaces to achieve ultra-fast, intelligent, and efficient photonic systems for next-generation optical communications.
{"title":"Deep-learning-based polarization-dependent switching metasurface in dual-band for optical communication","authors":"Yihan Yan, Yunkai Wu, Yangwen Wang, Jiahao Li, Jingtian Hu, Xu Wang","doi":"10.1515/nanoph-2025-0370","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0370","url":null,"abstract":"To address the critical limitations of conventional band-switching technologies – such as their slow speed, high energy consumption, and mechanical instability – this research introduces a novel deep-learning-driven framework for the intelligent inverse design of polarization-multiplexed metasurfaces. This approach represents a paradigm shift from traditional methods by enabling single-step, computational discovery of metasurface designs that directly encode two distinct optical functions within a single flat device. At the heart of our framework is a custom-designed deep neural network that seamlessly integrates parallel convolutional layers for robust feature extraction with cascaded regression modules for high-precision prediction. This hybrid architecture allows us to engineer sub-wavelength meta-atoms to achieve desired optical responses rigorously. As a groundbreaking demonstration, we designed and optimized a metasurface that achieves dynamic band switching solely through polarization modulation: it generates a targeted transmission peak in the O-band (1,260–1,360 nm) under <jats:italic>y</jats:italic> -polarization and an independent peak in the C-band (1,530–1,565 nm) under <jats:italic>x</jats:italic> -polarization. This mechanism eliminates the need for moving parts. The resulting device exhibits a switching efficiency orders of magnitude greater than its mechanical counterparts, while simultaneously offering enhanced stability, lower power consumption, and inherent adaptability for reconfigurable optical networks. Our work not only validates a specific device but also establishes a robust and generalizable design paradigm, underscoring the transformative potential of uniting deep learning with metasurfaces to achieve ultra-fast, intelligent, and efficient photonic systems for next-generation optical communications.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"26 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145531473","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}
We report the first demonstration of surface relief formation by irradiating material with non-degenerate hybrid vortex modes. These modes are formed via the coherent superposition of two Laguerre–Gaussian (LG) modes with different orbital angular momentum (OAM) indices, and they carry non-zero OAM. Intriguingly, the spatially localized vortex fields, which are associated with multiple phase singularities of the non-degenerate hybrid vortex modes and spin angular momentum (SAM) of circular polarization, can be visualized as fist-like protrusions produced within the fabricated surface relief structures. This demonstration offers new insights into fundamental light–matter interactions via SAM-OAM coupling effects and opens the door to a deeper understanding of the mechanisms underlying the formation of vortex lattices and vortex–antivortex pairs in condensed matter physics. This demonstration also provides a method for fabricating chiral surface relief structures with an odd number of spiral arms, which may be utilized in advanced optical data storage and chiral metasurface applications.
{"title":"Surface relief formation with light possessing multiple vortices","authors":"Junjie Zhao, Kazuro Kizaki, Atsushi Taguchi, Madoka Ono, Soki Hirayama, Takashige Omatsu","doi":"10.1515/nanoph-2025-0387","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0387","url":null,"abstract":"We report the first demonstration of surface relief formation by irradiating material with non-degenerate hybrid vortex modes. These modes are formed via the coherent superposition of two Laguerre–Gaussian (LG) modes with different orbital angular momentum (OAM) indices, and they carry non-zero OAM. Intriguingly, the spatially localized vortex fields, which are associated with multiple phase singularities of the non-degenerate hybrid vortex modes and spin angular momentum (SAM) of circular polarization, can be visualized as fist-like protrusions produced within the fabricated surface relief structures. This demonstration offers new insights into fundamental light–matter interactions via SAM-OAM coupling effects and opens the door to a deeper understanding of the mechanisms underlying the formation of vortex lattices and vortex–antivortex pairs in condensed matter physics. This demonstration also provides a method for fabricating chiral surface relief structures with an odd number of spiral arms, which may be utilized in advanced optical data storage and chiral metasurface applications.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"64 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145531476","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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