Pub Date : 2025-10-31DOI: 10.1515/nanoph-2025-0433
Yiqi Ye, Hang Su, Yuetian Jia, Baoli Li, Min Gu, Xinyuan Fang
Three-dimensional (3D) displays reconstruct spatial light fields, providing immersive stereoscopic experiences with depth perception. Multiview 3D displays are particularly attractive, delivering multiple perspective images to different spatial positions for glasses-free multi-user observation and continuous motion parallax. However, achieving both high-capacity information encoding and a large field-of-view (FOV) remains challenging. Here, we propose a high-capacity, large-FOV holographic multiview 3D display by integrating orbital angular momentum (OAM) multiplexing with forked nanograting arrays fabricated via two-photon lithography (TPL). A 3 × 3 hologram array is loaded onto a spatial light modulator (SLM), with each sub-hologram encodes four orthogonal OAM modes, enabling parallel high-capacity information storage. Each OAM channel is diffracted by the corresponding forked nanograting array into multiple discrete directions (experimentally verified up to nine), effectively expanding the accessible viewing range. A dual dynamic control mechanism allows real-time hologram refresh on the SLM and selective switching of different OAM-encoded image sets without computational latency. Experiments under 532 nm illumination successfully reconstruct eight independent 3D scenes with nine viewpoints across a 30° field of view, achieving an average structural similarity index (SSIM) of ∼0.81 with negligible crosstalk. This work establishes a reconfigurable, high-throughput, large-FOV multiview 3D display framework, with potential for portable AR/VR devices, holographic communication and medical surgical navigation.
{"title":"High-capacity multiview display with large viewing angle via orbital angular momentum-encoded nanograting arrays","authors":"Yiqi Ye, Hang Su, Yuetian Jia, Baoli Li, Min Gu, Xinyuan Fang","doi":"10.1515/nanoph-2025-0433","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0433","url":null,"abstract":"Three-dimensional (3D) displays reconstruct spatial light fields, providing immersive stereoscopic experiences with depth perception. Multiview 3D displays are particularly attractive, delivering multiple perspective images to different spatial positions for glasses-free multi-user observation and continuous motion parallax. However, achieving both high-capacity information encoding and a large field-of-view (FOV) remains challenging. Here, we propose a high-capacity, large-FOV holographic multiview 3D display by integrating orbital angular momentum (OAM) multiplexing with forked nanograting arrays fabricated via two-photon lithography (TPL). A 3 × 3 hologram array is loaded onto a spatial light modulator (SLM), with each sub-hologram encodes four orthogonal OAM modes, enabling parallel high-capacity information storage. Each OAM channel is diffracted by the corresponding forked nanograting array into multiple discrete directions (experimentally verified up to nine), effectively expanding the accessible viewing range. A dual dynamic control mechanism allows real-time hologram refresh on the SLM and selective switching of different OAM-encoded image sets without computational latency. Experiments under 532 nm illumination successfully reconstruct eight independent 3D scenes with nine viewpoints across a 30° field of view, achieving an average structural similarity index (SSIM) of ∼0.81 with negligible crosstalk. This work establishes a reconfigurable, high-throughput, large-FOV multiview 3D display framework, with potential for portable AR/VR devices, holographic communication and medical surgical navigation.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"27 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145412032","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}
Magnetic-optical Kerr or Faraday effects have been widely used to measure magnetic domain structures by analyzing far-field polarization properties, with resolution limited by the wavelength scale of light. Here, we propose a methodology to measure the magnetic domain at a deep-subwavelength scale by investigating the interactions between a magnetic film and a topological meron spin lattice on the surface of hyperbolic metamaterials (HMMs), which support high- k modes. By introducing a grating structure on the HMM surface to excite volume plasmon polaritons, optical meron spin lattices are formed on the outer surface of the HMM. Subsequently, utilizing the spin–orbit couplings of the topological lattices in the presence of magnetization, a 0.158 λ resolution and 100 % high-precision detection of the magnetic domain structures with random polar orientations was achieved by altering the incident polarizations from right-handed to left-handed circular polarizations and summing the out-of-plane spin distributions. The findings offer opportunities for the visualization of magnetic domain structure with polar orientation of magnetization and in turn for the development of novel photonic spin topologies using complex magnetization patterns.
{"title":"Deep-subwavelength resolution detection of polar magnetization by optical spin meron lattices on hyperbolic metamaterials","authors":"Jingya Wu, Weiyu Wei, Kefeng Guo, Xiangyang Xie, Aiping Yang, Xinrui Lei, Peng Shi, Qiwen Zhan, Xiaocong Yuan","doi":"10.1515/nanoph-2025-0424","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0424","url":null,"abstract":"Magnetic-optical Kerr or Faraday effects have been widely used to measure magnetic domain structures by analyzing far-field polarization properties, with resolution limited by the wavelength scale of light. Here, we propose a methodology to measure the magnetic domain at a deep-subwavelength scale by investigating the interactions between a magnetic film and a topological meron spin lattice on the surface of hyperbolic metamaterials (HMMs), which support high- k modes. By introducing a grating structure on the HMM surface to excite volume plasmon polaritons, optical meron spin lattices are formed on the outer surface of the HMM. Subsequently, utilizing the spin–orbit couplings of the topological lattices in the presence of magnetization, a 0.158 <jats:italic>λ</jats:italic> resolution and 100 % high-precision detection of the magnetic domain structures with random polar orientations was achieved by altering the incident polarizations from right-handed to left-handed circular polarizations and summing the out-of-plane spin distributions. The findings offer opportunities for the visualization of magnetic domain structure with polar orientation of magnetization and in turn for the development of novel photonic spin topologies using complex magnetization patterns.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"1 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145405136","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 : 2025-10-30DOI: 10.1515/nanoph-2025-0377
Xiaodong Shi, Angela Anna Baiju, Xu Chen, Sakthi Sanjeev Mohanraj, Sihao Wang, Veerendra Dhyani, Biveen Shajilal, Mengyao Zhao, Ran Yang, Yue Li, Guangxing Wu, Hao Hao, Victor Leong, Ping Koy Lam, Di Zhu
Squeezed states of light play a key role in quantum-enhanced sensing and continuous-variable quantum information processing. Realizing integrated squeezed light sources is crucial for developing compact and scalable photonic quantum systems. In this work, we demonstrate on-chip broadband vacuum squeezing at telecommunication wavelengths on the thin-film lithium niobate (TFLN) platform. Our device integrates periodically poled lithium niobate (PPLN) nanophotonic waveguides with low-loss edge couplers, comprising bilayer inverse tapers and an SU-8 polymer waveguide. This configuration achieves a fiber-to-chip coupling loss of 1.4 dB and a total homodyne detection loss of 4.0 dB, enabling a measured squeezing level of 1.4 dB. Additional measurements in a more efficient PPLN waveguide (without low-loss couplers) infer an on-chip squeezing level of approximately 10 dB at a pump power of 62 mW. These results underscore the potential of TFLN platform for efficient and scalable squeezed light generation.
{"title":"Squeezed light generation in periodically poled thin-film lithium niobate waveguides","authors":"Xiaodong Shi, Angela Anna Baiju, Xu Chen, Sakthi Sanjeev Mohanraj, Sihao Wang, Veerendra Dhyani, Biveen Shajilal, Mengyao Zhao, Ran Yang, Yue Li, Guangxing Wu, Hao Hao, Victor Leong, Ping Koy Lam, Di Zhu","doi":"10.1515/nanoph-2025-0377","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0377","url":null,"abstract":"Squeezed states of light play a key role in quantum-enhanced sensing and continuous-variable quantum information processing. Realizing integrated squeezed light sources is crucial for developing compact and scalable photonic quantum systems. In this work, we demonstrate on-chip broadband vacuum squeezing at telecommunication wavelengths on the thin-film lithium niobate (TFLN) platform. Our device integrates periodically poled lithium niobate (PPLN) nanophotonic waveguides with low-loss edge couplers, comprising bilayer inverse tapers and an SU-8 polymer waveguide. This configuration achieves a fiber-to-chip coupling loss of 1.4 dB and a total homodyne detection loss of 4.0 dB, enabling a measured squeezing level of 1.4 dB. Additional measurements in a more efficient PPLN waveguide (without low-loss couplers) infer an on-chip squeezing level of approximately 10 dB at a pump power of 62 mW. These results underscore the potential of TFLN platform for efficient and scalable squeezed light generation.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"124 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145405137","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 : 2025-10-29DOI: 10.1515/nanoph-2025-0358
Xiaoyong He, Wenhan Cao, Fangting Lin
Proposed by von Neuman and Wigner in 1929, bound states in the continuum (BIC) exhibit the merits of ultrahigh Q–factor and strongly confined modes, solving the inherent high dissipation of metamaterials (MMs) and plasmonic devices. Dirac semimetal (DSM) possesses the advantages of high carrier mobility and outstanding tunable properties, which provides avenues for the design of performance functional devices. This review focuses on recent progresses of the DSM (graphene and 3D Dirac semimetals, e.g. Cd 3 As 2 ) and other novel materials ( e.g. MoS 2 , borophene, GaSe) based BIC MMs, including the effects of Fermi levels, resonators types, and operation frequency ranges. Some related interesting phenomena, such as tunable Fano resonance, strong epsilon-nearly-zero and nonlinear harmonic effects, together with a brief prospect on the future development trends of DSM MMs, have been given and discussed. This work also provides a useful guideline to understand the tunable mechanism of the DSM devices and develop high performance functional devices applied in the fields of wireless communications, security detection, and sub-millimeter astronomical observations, e.g. filters, modulators and polarizers.
{"title":"Tunable BIC metamaterials with Dirac semimetals","authors":"Xiaoyong He, Wenhan Cao, Fangting Lin","doi":"10.1515/nanoph-2025-0358","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0358","url":null,"abstract":"Proposed by von Neuman and Wigner in 1929, bound states in the continuum (BIC) exhibit the merits of ultrahigh <jats:italic>Q–factor</jats:italic> and strongly confined modes, solving the inherent high dissipation of metamaterials (MMs) and plasmonic devices. Dirac semimetal (DSM) possesses the advantages of high carrier mobility and outstanding tunable properties, which provides avenues for the design of performance functional devices. This review focuses on recent progresses of the DSM (graphene and 3D Dirac semimetals, <jats:italic>e.g.</jats:italic> Cd <jats:sub>3</jats:sub> As <jats:sub>2</jats:sub> ) and other novel materials ( <jats:italic>e.g.</jats:italic> MoS <jats:sub>2</jats:sub> , borophene, GaSe) based BIC MMs, including the effects of Fermi levels, resonators types, and operation frequency ranges. Some related interesting phenomena, such as tunable Fano resonance, strong epsilon-nearly-zero and nonlinear harmonic effects, together with a brief prospect on the future development trends of DSM MMs, have been given and discussed. This work also provides a useful guideline to understand the tunable mechanism of the DSM devices and develop high performance functional devices applied in the fields of wireless communications, security detection, and sub-millimeter astronomical observations, <jats:italic>e.g.</jats:italic> filters, modulators and polarizers.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"60 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145397113","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}
Photonic quasicrystals, generated through the interference of multiple vortex beams, exhibit rich and complex topological landscapes. However, unlike their periodic counterparts, they have far lacked the same level of controllability and reconfigurability. In this work, we develop a theoretical model to characterize the spin topology of photonic quasicrystals and uncover the intrinsic substructure underlying their quasi-periodic spin textures. By analyzing the formation mechanisms, we demonstrate the controlled decomposition and topological annihilation of individual sublattices within a quasicrystalline configuration. Based on this, we propose a phase-modulation method to reconfigure these topological states. We demonstrate that a quasicrystal with octagonal symmetry can be decomposed into two square meron lattices with a relative twist. This method is further extended to create more complex quasicrystals, where selective sublattice activation leads to meron bags. These findings provide new insights into both the static design and active manipulation of topological quasicrystals of light, paving the way for programmable topological photonic platforms with high spatial complexity and functional versatility.
{"title":"Topological decomposition and transformation of photonic quasicrystals","authors":"Hao Wang, Houan Teng, Jinzhan Zhong, Xinrui Lei, Qiwen Zhan","doi":"10.1515/nanoph-2025-0384","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0384","url":null,"abstract":"Photonic quasicrystals, generated through the interference of multiple vortex beams, exhibit rich and complex topological landscapes. However, unlike their periodic counterparts, they have far lacked the same level of controllability and reconfigurability. In this work, we develop a theoretical model to characterize the spin topology of photonic quasicrystals and uncover the intrinsic substructure underlying their quasi-periodic spin textures. By analyzing the formation mechanisms, we demonstrate the controlled decomposition and topological annihilation of individual sublattices within a quasicrystalline configuration. Based on this, we propose a phase-modulation method to reconfigure these topological states. We demonstrate that a quasicrystal with octagonal symmetry can be decomposed into two square meron lattices with a relative twist. This method is further extended to create more complex quasicrystals, where selective sublattice activation leads to meron bags. These findings provide new insights into both the static design and active manipulation of topological quasicrystals of light, paving the way for programmable topological photonic platforms with high spatial complexity and functional versatility.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"10 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145397114","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}
Achieving high electromagnetic (EM) wave transmission with excellent angular stability is crucial for communication, detection, and guidance but remains challenging, especially when integrating other functions like out-of-band radar cross-section (RCS) reduction, which often degrades transmission. In this work, we propose to solve this problem by utilizing the longitudinal design freedom of metasurface. To this end, a typical longitudinally-coupled structure is proposed as the meta-atom for designing metasurfaces, which is composed of one layer of metallic meshes and one layer of metallic patch. By leveraging the synergistic effect of the plasma oscillation of the metallic mesh and the Lorentz resonance effect of the metal patch within meta-atom, we obtain a dual-polarization angle stable EM window (0°–80°) within the operating band. On this basis, without altering the structural parameters of the meta-atom, we utilize the longitudinal dimension to encode the reflection phases of out-of-band EM waves by flipping the meta-atom structure longitudinally, which can integrate out-of-band radar cross-section (RCS) reduction function without affecting the in-band transmission performance. To demonstrate this idea, prototypes were designed, fabricated and measured. Fabricated prototypes show good agreement between measurements and simulations, validating the method. This opens new paths for multifunctional EM windows in next-gen communication and radar systems.
{"title":"Dual-polarization electromagnetic window simultaneously with extreme in-band angle-stability and out-of-band RCS reduction empowered by flip-coding metasurface","authors":"Heng-Yang Luo, Tie-Fu Li, Jia-Fu Wang, Yu-Xiang Jia, Rui-Chao Zhu, Xiao-Long Liang, Zhi-Hui Zhang, Min Zhou, Shao-Bo Qu","doi":"10.1515/nanoph-2025-0386","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0386","url":null,"abstract":"Achieving high electromagnetic (EM) wave transmission with excellent angular stability is crucial for communication, detection, and guidance but remains challenging, especially when integrating other functions like out-of-band radar cross-section (RCS) reduction, which often degrades transmission. In this work, we propose to solve this problem by utilizing the longitudinal design freedom of metasurface. To this end, a typical longitudinally-coupled structure is proposed as the meta-atom for designing metasurfaces, which is composed of one layer of metallic meshes and one layer of metallic patch. By leveraging the synergistic effect of the plasma oscillation of the metallic mesh and the Lorentz resonance effect of the metal patch within meta-atom, we obtain a dual-polarization angle stable EM window (0°–80°) within the operating band. On this basis, without altering the structural parameters of the meta-atom, we utilize the longitudinal dimension to encode the reflection phases of out-of-band EM waves by flipping the meta-atom structure longitudinally, which can integrate out-of-band radar cross-section (RCS) reduction function without affecting the in-band transmission performance. To demonstrate this idea, prototypes were designed, fabricated and measured. Fabricated prototypes show good agreement between measurements and simulations, validating the method. This opens new paths for multifunctional EM windows in next-gen communication and radar systems.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"65 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145397117","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 : 2025-10-28DOI: 10.1515/nanoph-2025-0291
Yinghui Gao, Yinping Miao, Xiaolan Li, Wangyang Nie, Yanxi Wang, Zhuoyang Han, Youlian Wang, Xuqi Wang, Rui Yang, Ran Wang, Jianquan Yao
Platinum diselenide (PtSe 2 ), a two-dimensional material, has shown exceptional promise in photodetection applications because of its air stability, high carrier mobility, and layer-tunable bandgap. However, conventional photoconductive modes face challenges with high dark currents. To address this limitation, all-optical fiber detection technology with high sensitivity and response, has emerged as a promising approach for developing PtSe 2 , based devices. In this study, a high-sensitivity broadband photodetector based on PtSe 2 with a cascaded Fabry–Pérot interferometer (FPI) is proposed, which utilises the broad spectral absorption property of PtSe 2 and the interference enhancement mechanism of cascaded F–P cavities to achieve high-sensitivity broadband photodetection. The experimental results show that the detector has excellent spectral response in the 808–1,550 nm band, with a sensitivity of 3.867 nm/mW at 980 nm and a response time of 37.43 ms/129.17 ms. The sensitivity at 1,550 nm is up to 134.014 nm/mW, with a response time of 75.74 ms/28.66 ms. The double matching of 0.8 eV energy and PtSe 2 material, which is situated in the range of the material intrinsic absorption peak (1,200–1,600 nm), is responsible for the excellent sensitivity at 1,550 nm. It is also highly matched with the interband jump energy level, which generates more hot carriers per unit optical power and thereby increases the photothermal conversion efficiency. This study provides a new solution for the design of high-sensitivity, ultra-wideband optical fiber photodetectors, which has important potential applications in optical communications, environmental monitoring, and sensing.
{"title":"Highly sensitive broadband photodetector based on PtSe 2 photothermal effect and fiber harmonic Vernier effect","authors":"Yinghui Gao, Yinping Miao, Xiaolan Li, Wangyang Nie, Yanxi Wang, Zhuoyang Han, Youlian Wang, Xuqi Wang, Rui Yang, Ran Wang, Jianquan Yao","doi":"10.1515/nanoph-2025-0291","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0291","url":null,"abstract":"Platinum diselenide (PtSe <jats:sub>2</jats:sub> ), a two-dimensional material, has shown exceptional promise in photodetection applications because of its air stability, high carrier mobility, and layer-tunable bandgap. However, conventional photoconductive modes face challenges with high dark currents. To address this limitation, all-optical fiber detection technology with high sensitivity and response, has emerged as a promising approach for developing PtSe <jats:sub>2</jats:sub> , based devices. In this study, a high-sensitivity broadband photodetector based on PtSe <jats:sub>2</jats:sub> with a cascaded Fabry–Pérot interferometer (FPI) is proposed, which utilises the broad spectral absorption property of PtSe <jats:sub>2</jats:sub> and the interference enhancement mechanism of cascaded F–P cavities to achieve high-sensitivity broadband photodetection. The experimental results show that the detector has excellent spectral response in the 808–1,550 nm band, with a sensitivity of 3.867 nm/mW at 980 nm and a response time of 37.43 ms/129.17 ms. The sensitivity at 1,550 nm is up to 134.014 nm/mW, with a response time of 75.74 ms/28.66 ms. The double matching of 0.8 eV energy and PtSe <jats:sub>2</jats:sub> material, which is situated in the range of the material intrinsic absorption peak (1,200–1,600 nm), is responsible for the excellent sensitivity at 1,550 nm. It is also highly matched with the interband jump energy level, which generates more hot carriers per unit optical power and thereby increases the photothermal conversion efficiency. This study provides a new solution for the design of high-sensitivity, ultra-wideband optical fiber photodetectors, which has important potential applications in optical communications, environmental monitoring, and sensing.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"17 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145397116","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 : 2025-10-27DOI: 10.1515/nanoph-2025-0466
Ziliang Ruan, Xijie Wang, Bin Chen, Gengxin Chen, Liu Liu
Thin-film lithium niobate (TFLN) has emerged as an attractive platform for integrated tunable photonic filters owing to its strong electro-optic response and low optical loss. However, conventional resonant filters, such as micro-rings, are intrinsically constrained by a limited free spectral range (FSR), which hinders their use in broadband and multi-channel operations. Here we present a TFLN-based add-drop filter that overcomes this limitation by employing a side-coupled travelling-wave Fabry–Pérot (FP) cavity formed with asymmetric multimode waveguide gratings (AMWGs). By engineering the inter-modal coupling through waveguide width tailoring and the reflection bandwidth of AMWGs, we realize a cavity with an intrinsic quality factor of 2.5 × 10 5 . The add-drop filter device also exhibits an FSR-free response across 1,500–1,630 nm wavelength band. A single resonance with a through-port extinction ratio of 20.23 dB and a drop-port insertion loss of 1.81 dB. Wavelength tuning by thermo-optic and electro-optic effect is demonstrated with efficiencies of 34.82 pm/K and 6.9 pm/V, respectively. Furthermore, a four-channel add-drop filter array with 3.2 nm channel spacing and 1.35 dB total through-port insertion loss validates the scalability of the present device. This work demonstrates an efficient approach to overcome the FSR constraint of sharp wavelength filters on TFLN. It can be potentially adopted in dense-wavelength-division-multiplexing communication systems, narrow-bandwidth microwave photonic filters, or high-resolution spectrometers.
{"title":"Multi-channel and free-spectral-range-free tunable add-drop filters on thin-film lithium niobate","authors":"Ziliang Ruan, Xijie Wang, Bin Chen, Gengxin Chen, Liu Liu","doi":"10.1515/nanoph-2025-0466","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0466","url":null,"abstract":"Thin-film lithium niobate (TFLN) has emerged as an attractive platform for integrated tunable photonic filters owing to its strong electro-optic response and low optical loss. However, conventional resonant filters, such as micro-rings, are intrinsically constrained by a limited free spectral range (FSR), which hinders their use in broadband and multi-channel operations. Here we present a TFLN-based add-drop filter that overcomes this limitation by employing a side-coupled travelling-wave Fabry–Pérot (FP) cavity formed with asymmetric multimode waveguide gratings (AMWGs). By engineering the inter-modal coupling through waveguide width tailoring and the reflection bandwidth of AMWGs, we realize a cavity with an intrinsic quality factor of 2.5 × 10 <jats:sup>5</jats:sup> . The add-drop filter device also exhibits an FSR-free response across 1,500–1,630 nm wavelength band. A single resonance with a through-port extinction ratio of 20.23 dB and a drop-port insertion loss of 1.81 dB. Wavelength tuning by thermo-optic and electro-optic effect is demonstrated with efficiencies of 34.82 pm/K and 6.9 pm/V, respectively. Furthermore, a four-channel add-drop filter array with 3.2 nm channel spacing and 1.35 dB total through-port insertion loss validates the scalability of the present device. This work demonstrates an efficient approach to overcome the FSR constraint of sharp wavelength filters on TFLN. It can be potentially adopted in dense-wavelength-division-multiplexing communication systems, narrow-bandwidth microwave photonic filters, or high-resolution spectrometers.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"62 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145397119","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 : 2025-10-27DOI: 10.1515/nanoph-2025-0410
Inchul Woo, Hyeokjung Kang, Namkyoo Park
For vivid, immersive overlay of virtual images onto background scenes in augmented reality (AR) applications, it is crucial for the display element to achieve controllability of spectral selectivity and transmittance level. At the current stage, the transmittance of self-emissive transparent displays is limited to at most ∼60 %, constrained by the fill factor of emissive regions, restricting their scalability for immersive experiences. Although projection-based transparent screens using frequency-selective scatterers offer a promising alternative, the platforms suffer from spectral broadening and instability originating from color-dependent scattering and inter-scatterer coupling. Here, we present a transparent screen architecture based on multicolor nanoring arrays. By tuning the nanoring’s resonance via inner-aperture size engineering, the architecture enables dense, symmetric RGB arrays with isolated and homogenized scattering responses. For inter-scatterer distances of 100–200+ nm, full-wave simulations confirm the robustness of well-isolated RGB reflections (FWHM < 25 nm), along with exceptional tunability of transmittance (50 % to above 80 %). As a platform for AR displays, we demonstrate the widest reported transparency-control range without any penalty to color balance or spectral selectivity. We also analyze the gamut area of projected images across transmittance levels, achieving a net gamut expansion (+11.0 % p at Λ = 120 nm; +5.5 % p at Λ = 190 nm) from the spectral narrowing of projection sources, and further propose a practical design map linking the maximum allowable transmittance to the ambient-to-source noise ratio. Our nanoring-based architecture provides a robust and scalable platform for next-generation transparent displays under real-world lighting conditions.
{"title":"Multicolor nanoring arrays with uniform and decoupled scattering for augmented reality displays","authors":"Inchul Woo, Hyeokjung Kang, Namkyoo Park","doi":"10.1515/nanoph-2025-0410","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0410","url":null,"abstract":"For vivid, immersive overlay of virtual images onto background scenes in augmented reality (AR) applications, it is crucial for the display element to achieve controllability of spectral selectivity and transmittance level. At the current stage, the transmittance of self-emissive transparent displays is limited to at most ∼60 %, constrained by the fill factor of emissive regions, restricting their scalability for immersive experiences. Although projection-based transparent screens using frequency-selective scatterers offer a promising alternative, the platforms suffer from spectral broadening and instability originating from color-dependent scattering and inter-scatterer coupling. Here, we present a transparent screen architecture based on multicolor nanoring arrays. By tuning the nanoring’s resonance via inner-aperture size engineering, the architecture enables dense, symmetric RGB arrays with isolated and homogenized scattering responses. For inter-scatterer distances of 100–200+ nm, full-wave simulations confirm the robustness of well-isolated RGB reflections (FWHM < 25 nm), along with exceptional tunability of transmittance (50 % to above 80 %). As a platform for AR displays, we demonstrate the widest reported transparency-control range without any penalty to color balance or spectral selectivity. We also analyze the gamut area of projected images across transmittance levels, achieving a net gamut expansion (+11.0 % p at Λ = 120 nm; +5.5 % p at Λ = 190 nm) from the spectral narrowing of projection sources, and further propose a practical design map linking the maximum allowable transmittance to the ambient-to-source noise ratio. Our nanoring-based architecture provides a robust and scalable platform for next-generation transparent displays under real-world lighting conditions.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"149 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145397120","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 : 2025-10-21DOI: 10.1515/nanoph-2025-0482
Miriam S Vitiello,Jerome Faist,Benjamin S Williams,Paolo De Natale
{"title":"Quantum cascade laser: 30 years of discoveries.","authors":"Miriam S Vitiello,Jerome Faist,Benjamin S Williams,Paolo De Natale","doi":"10.1515/nanoph-2025-0482","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0482","url":null,"abstract":"","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"144 1","pages":"3353-3354"},"PeriodicalIF":7.5,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145373830","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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