Pub Date : 2025-11-24DOI: 10.1515/nanoph-2025-0413
Zhiyuan Shi, Wei Jiang, Yanqing Lu, Weihua Zhang
This study presents a super-resolution light manipulation technique in the near-field region of a silicon nanolens array in the blue spectral range using a computer-generated holography technique. It allows us to focus light into a spot below 70 nm at arbitrarily given positions within the entire lens array using modulated incident fields. To achieve this, an inverse design algorithm is developed using multiaxis high-order Gaussian beam expansion. It effectively corrects aberrations in off-axis focal spots within each nanolens unit, resulting in high-quality nanofocused beams with an extended depth of focus. By superimposing discrete nanofocused spots, we can further synthesize complex intensity patterns across multiple nanolens units, achieving an intensity profile resolution of 80 nm. This offers a promising approach for super-resolution photolithography using visible light.
{"title":"Sub-100 nm manipulation of blue light over a large field of view using Si nanolens array","authors":"Zhiyuan Shi, Wei Jiang, Yanqing Lu, Weihua Zhang","doi":"10.1515/nanoph-2025-0413","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0413","url":null,"abstract":"This study presents a super-resolution light manipulation technique in the near-field region of a silicon nanolens array in the blue spectral range using a computer-generated holography technique. It allows us to focus light into a spot below 70 nm at arbitrarily given positions within the entire lens array using modulated incident fields. To achieve this, an inverse design algorithm is developed using multiaxis high-order Gaussian beam expansion. It effectively corrects aberrations in off-axis focal spots within each nanolens unit, resulting in high-quality nanofocused beams with an extended depth of focus. By superimposing discrete nanofocused spots, we can further synthesize complex intensity patterns across multiple nanolens units, achieving an intensity profile resolution of 80 nm. This offers a promising approach for super-resolution photolithography using visible light.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"191 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145592934","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 : 2025-11-24DOI: 10.1515/nanoph-2025-0335
Jiayu Huang, Run Li, Suo Wang, Qianqian Jia, Zichuan Xiang, Jinling Yang, Jinye Li, Jianguo Liu
Erbium-doped waveguide amplifiers (EDWAs) are vital for photonic integration, yet most are built on z-cut lithium niobate, incompatible with the mainstream x-cut platform. This work presents a combined theoretical and experimental study of polarization-dependent gain in x-cut Er:LNOI. Using Judd–Ofelt theory, we analyze how crystal orientation governs TE-mode coupling to Er 3+ ions, predicting stark differences in transition strengths between α - and π -polarizations. Experiments confirm these predictions: at 1,531 nm, the absorption and emission cross sections for α -polarization are 1.8 times larger than for π -polarization. At 1,550 nm, the α -polarization shows a gain coefficient of 3.3 dB/cm versus 2.2 dB/cm for π -polarization. In the small-signal regime, the α -polarized amplifier achieves 32.01 dB signal enhancement with 11.18 dB internal net gain. With 9.1 dBm on-chip input power, it delivers 21.18 mW unsaturated output power under pumping levels exceeding 200 mW. This work demonstrates feasible optical amplification on x-cut LNOI, providing crucial support for large-scale photonic and microwave photonic systems.
{"title":"Polarization-dependent gain characterization in x-cut LNOI erbium-doped waveguide amplifiers","authors":"Jiayu Huang, Run Li, Suo Wang, Qianqian Jia, Zichuan Xiang, Jinling Yang, Jinye Li, Jianguo Liu","doi":"10.1515/nanoph-2025-0335","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0335","url":null,"abstract":"Erbium-doped waveguide amplifiers (EDWAs) are vital for photonic integration, yet most are built on z-cut lithium niobate, incompatible with the mainstream x-cut platform. This work presents a combined theoretical and experimental study of polarization-dependent gain in x-cut Er:LNOI. Using Judd–Ofelt theory, we analyze how crystal orientation governs TE-mode coupling to Er <jats:sup>3+</jats:sup> ions, predicting stark differences in transition strengths between <jats:italic>α</jats:italic> - and <jats:italic>π</jats:italic> -polarizations. Experiments confirm these predictions: at 1,531 nm, the absorption and emission cross sections for <jats:italic>α</jats:italic> -polarization are 1.8 times larger than for <jats:italic>π</jats:italic> -polarization. At 1,550 nm, the <jats:italic>α</jats:italic> -polarization shows a gain coefficient of 3.3 dB/cm versus 2.2 dB/cm for <jats:italic>π</jats:italic> -polarization. In the small-signal regime, the <jats:italic>α</jats:italic> -polarized amplifier achieves 32.01 dB signal enhancement with 11.18 dB internal net gain. With 9.1 dBm on-chip input power, it delivers 21.18 mW unsaturated output power under pumping levels exceeding 200 mW. This work demonstrates feasible optical amplification on x-cut LNOI, providing crucial support for large-scale photonic and microwave photonic systems.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"1 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145583261","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}
Meta-optics have opened new possibilities for portable, high-performance microscopy, offering ultrathin and highly customizable wavefront control in scenarios where bulky optics limit adoption. Here, we use this capability to overcome the long-standing challenges of Fourier ptychography (FP), a powerful computational technique for wide-field, high-resolution quantitative phase imaging that traditionally depends on large optical elements and extensive angle scanning. Our compact meta-FP platform combines a 4-f metalens system for imaging miniaturization with a programmable thin-film transistor (TFT) panel to provide stable, angle-diverse plane-wave illumination without mechanical movement. To further accelerate imaging, we introduce a residual convolutional neural network (RCNN) model trained via transfer learning on conventional FP datasets, which allows for single-shot inference of high-resolution phase from low-resolution inputs. Experimental validations demonstrate nearly twofold resolution improvement (7.81 µm–3.91 µm), accurate quantitative phase recovery on phase standards with errors below 10 %, and dry-mass estimation of H1975 cells with an average deviation of approximately 12 %, while the best-performing regions exhibit deviations below 0.5 %. This integration of metasurface optics and artificial intelligence-driven reconstruction provides a promising pathway for fast and compact FP microscopy with applications in live-cell imaging, microfluidic monitoring, and point-of-care diagnostics.
元光学为便携式、高性能显微镜开辟了新的可能性，在笨重的光学限制采用的情况下，提供超薄和高度可定制的波前控制。在这里，我们利用这种能力来克服傅立叶平面摄影（FP）的长期挑战，FP是一种强大的计算技术，用于宽视场，高分辨率定量相位成像，传统上依赖于大光学元件和广角扫描。我们紧凑的meta-FP平台结合了用于成像小型化的4-f超透镜系统和可编程薄膜晶体管（TFT）面板，提供稳定的、角度多样的平面波照明，而无需机械运动。为了进一步加速成像，我们引入了一个残差卷积神经网络（RCNN）模型，该模型通过在传统FP数据集上的迁移学习进行训练，该模型允许从低分辨率输入中单次推断高分辨率相位。实验验证表明，分辨率提高了近两倍（7.81 μ m - 3.91 μ m），在相位标准上精确定量相位恢复，误差低于10%，H1975细胞的干质量估计平均偏差约为12%，而表现最好的区域的偏差低于0.5%。这种超表面光学和人工智能驱动重建的集成为快速和紧凑的FP显微镜提供了一条有前途的途径，可用于活细胞成像，微流体监测和即时诊断。
{"title":"Metasurface-based Fourier ptychographic microscopy","authors":"Cheng Hung Chu, Hao-Pin Chiu, Cheng Yu, Yuan-Chung Cheng, Ching-En Lin, Sunil Vyas, Yuan Luo","doi":"10.1515/nanoph-2025-0416","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0416","url":null,"abstract":"Meta-optics have opened new possibilities for portable, high-performance microscopy, offering ultrathin and highly customizable wavefront control in scenarios where bulky optics limit adoption. Here, we use this capability to overcome the long-standing challenges of Fourier ptychography (FP), a powerful computational technique for wide-field, high-resolution quantitative phase imaging that traditionally depends on large optical elements and extensive angle scanning. Our compact meta-FP platform combines a 4-f metalens system for imaging miniaturization with a programmable thin-film transistor (TFT) panel to provide stable, angle-diverse plane-wave illumination without mechanical movement. To further accelerate imaging, we introduce a residual convolutional neural network (RCNN) model trained via transfer learning on conventional FP datasets, which allows for single-shot inference of high-resolution phase from low-resolution inputs. Experimental validations demonstrate nearly twofold resolution improvement (7.81 µm–3.91 µm), accurate quantitative phase recovery on phase standards with errors below 10 %, and dry-mass estimation of H1975 cells with an average deviation of approximately 12 %, while the best-performing regions exhibit deviations below 0.5 %. This integration of metasurface optics and artificial intelligence-driven reconstruction provides a promising pathway for fast and compact FP microscopy with applications in live-cell imaging, microfluidic monitoring, and point-of-care diagnostics.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"29 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145592935","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 : 2025-11-24DOI: 10.1515/nanoph-2025-0474
Santiago A. Gomez, Emmi K. Pohjolainen, Dmitry Morozov, Ville Tiainen, J. Jussi Toppari, Gerrit Groenhof
Cucurbit[7]uril molecules form non-covalent host – guest complexes with small molecular dyes. In addition, cucurbit[7]uril can also bind gold nanoparticles on gold surfaces with a 0.9 nm gap, creating plasmonic nanocavities for the dyes, with extreme confinement of the electromagnetic field. For methylene blue in such cavities, single molecule strong coupling was inferred from a complete disappearance of a characteristic shoulder in its spectrum, attributed to dimer removal. Yet, the shoulder’s origin remains debated. Using atomistic simulations, we show that it arises from both dimerization and vibronic progression. While cucurbit[7]uril binding removes the dimer contribution, vibronic progression persists. As this conflicts with previous reports, we also measured the spectra. In line with our computations, the shoulder remains visible when cucurbit[7]uril binds methylene blue. These results clarify the spectral features and pave the way for atomistic models of single-molecule strong coupling in nanoparticle-on-mirror cavities.
{"title":"Disentangling the absorption lineshape of methylene blue for nanocavity strong coupling","authors":"Santiago A. Gomez, Emmi K. Pohjolainen, Dmitry Morozov, Ville Tiainen, J. Jussi Toppari, Gerrit Groenhof","doi":"10.1515/nanoph-2025-0474","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0474","url":null,"abstract":"Cucurbit[7]uril molecules form non-covalent host – guest complexes with small molecular dyes. In addition, cucurbit[7]uril can also bind gold nanoparticles on gold surfaces with a 0.9 nm gap, creating plasmonic nanocavities for the dyes, with extreme confinement of the electromagnetic field. For methylene blue in such cavities, single molecule strong coupling was inferred from a complete disappearance of a characteristic shoulder in its spectrum, attributed to dimer removal. Yet, the shoulder’s origin remains debated. Using atomistic simulations, we show that it arises from both dimerization and vibronic progression. While cucurbit[7]uril binding removes the dimer contribution, vibronic progression persists. As this conflicts with previous reports, we also measured the spectra. In line with our computations, the shoulder remains visible when cucurbit[7]uril binds methylene blue. These results clarify the spectral features and pave the way for atomistic models of single-molecule strong coupling in nanoparticle-on-mirror cavities.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"13 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145583262","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 : 2025-11-22DOI: 10.1515/nanoph-2025-0475
Keijiro Suzuki, Ryotaro Konoike, Siim Heinsalu, Shu Namiki, Hitoshi Kawashima, Kazuhiro Ikeda
Silicon photonics switches are emerging as a key technology for realizing energy-efficient networks, spanning from intra data center to wafer-scale interconnections. This review focuses on recent developments and prospects of silicon photonics switches operating in the O-band, which is widely used in computing networks designed for artificial intelligence and machine learning applications. We first review our recent works on O-band silicon photonics switches fabricated by 300-mm silicon photonics technology. Specifically, we have expanded the port count of our O-band switches from 8 × 8 to 32 × 32 implemented with double Mach–Zehnder switch elements for a broad operating bandwidth. This switch achieved a 70-nm bandwidth for a crosstalk of less than −20 dB, and an average on-chip loss of 11.8 dB. Next, we discuss switch topologies optimized for wafer-scale interconnection. Conventional switch topologies typically have their input and output ports at opposite ends of the switch matrix, respectively, which poses challenges of long propagation distances and many waveguide intersections for off-chip planar waveguide routing to connect xPUs on substrate. To address this, we propose a topology where input and output ports are placed adjacently. An O-band 8 × 8 switch based on this topology was fabricated and experimentally demonstrated. Finally, we discuss the prospects and challenges of silicon photonic switches. Key issues include insertion loss, switching speed, crosstalk and operating bandwidth, and polarization dependence. These aspects are examined with reference to reports from other research groups, highlighting both current limitations and potential directions for further improvement.
{"title":"Large-scale silicon photonics switches for AI/ML interconnections based on a 300-mm CMOS pilot line","authors":"Keijiro Suzuki, Ryotaro Konoike, Siim Heinsalu, Shu Namiki, Hitoshi Kawashima, Kazuhiro Ikeda","doi":"10.1515/nanoph-2025-0475","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0475","url":null,"abstract":"Silicon photonics switches are emerging as a key technology for realizing energy-efficient networks, spanning from intra data center to wafer-scale interconnections. This review focuses on recent developments and prospects of silicon photonics switches operating in the O-band, which is widely used in computing networks designed for artificial intelligence and machine learning applications. We first review our recent works on O-band silicon photonics switches fabricated by 300-mm silicon photonics technology. Specifically, we have expanded the port count of our O-band switches from 8 × 8 to 32 × 32 implemented with double Mach–Zehnder switch elements for a broad operating bandwidth. This switch achieved a 70-nm bandwidth for a crosstalk of less than −20 dB, and an average on-chip loss of 11.8 dB. Next, we discuss switch topologies optimized for wafer-scale interconnection. Conventional switch topologies typically have their input and output ports at opposite ends of the switch matrix, respectively, which poses challenges of long propagation distances and many waveguide intersections for off-chip planar waveguide routing to connect xPUs on substrate. To address this, we propose a topology where input and output ports are placed adjacently. An O-band 8 × 8 switch based on this topology was fabricated and experimentally demonstrated. Finally, we discuss the prospects and challenges of silicon photonic switches. Key issues include insertion loss, switching speed, crosstalk and operating bandwidth, and polarization dependence. These aspects are examined with reference to reports from other research groups, highlighting both current limitations and potential directions for further improvement.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"8 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145567130","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 : 2025-11-22DOI: 10.1515/nanoph-2025-0415
Xingye Yang, Alexander Antonov, Haiyang Hu, Andreas Tittl
Bound states in the continuum (BICs) provide exceptional light confinement due to their inherent decoupling from radiative channels. Small symmetry breaking transforms BIC into quasi-BIC (qBIC) that couples to free-space radiation enabling ultra-high-quality-factor (Q-factor) resonances desirable for refractive index (RI) sensing. In practical implementations, geometric asymmetry is typically employed. However, since the radiative loss remains fixed once fabricated, such metasurfaces exhibit only a horizontal shift of the resonance spectrum in RI sensing, without modification of its overall shape. Here, we demonstrate a permittivity-asymmetric qBIC (ε-qBIC) metasurface, which encodes environmental refractive index variations directly into the asymmetry factor, resulting in an index response involving both resonance wavelength shift and modulation variation. In addition to exhibiting a competitive transmittance sensitivity of ∼5,300 %/RIU under single-wavelength conditions, the ε -qBIC design provides a substantially improved linear response. Specifically, the linear window area of its sensing data distribution, calculated as the integrated wavelength region where the linearity parameter remains above the preset threshold, is 104 times larger than that of the geometry-asymmetric qBIC (g-qBIC), enabling more robust and reliable single-wavelength signal readout. Additionally, numerical results reveal that environmental permittivity asymmetry can optically restore the g-qBIC to a state with ultra-high-Q (over 10 7 ), approaching the BIC condition. Unlike traditional BICs, which are typically inaccessible once perturbed, the permittivity-restored BIC becomes accessible through environmental perturbations. These findings suggest an alternative design strategy for developing high-performance photonic devices for practical sensing applications.
{"title":"Permittivity-asymmetric qBIC metasurfaces for refractive index sensing","authors":"Xingye Yang, Alexander Antonov, Haiyang Hu, Andreas Tittl","doi":"10.1515/nanoph-2025-0415","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0415","url":null,"abstract":"Bound states in the continuum (BICs) provide exceptional light confinement due to their inherent decoupling from radiative channels. Small symmetry breaking transforms BIC into quasi-BIC (qBIC) that couples to free-space radiation enabling ultra-high-quality-factor (Q-factor) resonances desirable for refractive index (RI) sensing. In practical implementations, geometric asymmetry is typically employed. However, since the radiative loss remains fixed once fabricated, such metasurfaces exhibit only a horizontal shift of the resonance spectrum in RI sensing, without modification of its overall shape. Here, we demonstrate a permittivity-asymmetric qBIC (ε-qBIC) metasurface, which encodes environmental refractive index variations directly into the asymmetry factor, resulting in an index response involving both resonance wavelength shift and modulation variation. In addition to exhibiting a competitive transmittance sensitivity of ∼5,300 %/RIU under single-wavelength conditions, the <jats:italic>ε</jats:italic> -qBIC design provides a substantially improved linear response. Specifically, the linear window area of its sensing data distribution, calculated as the integrated wavelength region where the linearity parameter remains above the preset threshold, is 104 times larger than that of the geometry-asymmetric qBIC (g-qBIC), enabling more robust and reliable single-wavelength signal readout. Additionally, numerical results reveal that environmental permittivity asymmetry can optically restore the g-qBIC to a state with ultra-high-Q (over 10 <jats:sup>7</jats:sup> ), approaching the BIC condition. Unlike traditional BICs, which are typically inaccessible once perturbed, the permittivity-restored BIC becomes accessible through environmental perturbations. These findings suggest an alternative design strategy for developing high-performance photonic devices for practical sensing applications.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"179 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145567112","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}
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.
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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}
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