Pub Date : 2025-11-29DOI: 10.1515/nanoph-2025-0461
Laura Bollmers, Noah Spiegelberg, Michael Rüsing, Christof Eigner, Laura Padberg, Christine Silberhorn
Periodically poled thin-film lithium niobate (TFLN) crystals are the fundamental building block for highly-efficient quantum light sources and frequency converters. The efficiency of these devices is strongly dependent on the interaction length between the light and the nonlinear material, scaling quadratically with this parameter. Nevertheless, the fabrication of long, continuously poled areas in TFLN remains challenging, the length of continuously poled areas rarely exceeds 10 mm. In this work, we demonstrate a significant progress in this field achieving the periodic poling of continuous poled areas of 70 mm length with a 3 μm poling period and a close to 50 % duty cycle. We compare two poling electrode design approaches to fabricate long, continuous poled areas. The first approach involves the poling of a single, continuous 70 mm long electrode. The second utilize a segmented approach including the poling of more than 20 individual sections forming together a 70 mm long poling area with no stitching errors. While the continuous electrode allows for faster fabrication, the segmented approach allows to individually optimize the poling resulting in less duty cycle variation. A detailed analysis of the periodic poling results reveals that the results of both are consistent with previously reported poling outcomes for shorter devices. Thus, we demonstrate wafer-scale periodic poling exceeding chiplet-size without any loss in the periodic poling quality. Our work presents a key step towards highly-efficient, narrow-bandwidth and low-pump power nonlinear optical devices.
{"title":"Segmented finger electrodes to optimize ultra-long continuous wafer-scale periodic poling in thin-film lithium niobate","authors":"Laura Bollmers, Noah Spiegelberg, Michael Rüsing, Christof Eigner, Laura Padberg, Christine Silberhorn","doi":"10.1515/nanoph-2025-0461","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0461","url":null,"abstract":"Periodically poled thin-film lithium niobate (TFLN) crystals are the fundamental building block for highly-efficient quantum light sources and frequency converters. The efficiency of these devices is strongly dependent on the interaction length between the light and the nonlinear material, scaling quadratically with this parameter. Nevertheless, the fabrication of long, continuously poled areas in TFLN remains challenging, the length of continuously poled areas rarely exceeds 10 mm. In this work, we demonstrate a significant progress in this field achieving the periodic poling of continuous poled areas of 70 mm length with a 3 μm poling period and a close to 50 % duty cycle. We compare two poling electrode design approaches to fabricate long, continuous poled areas. The first approach involves the poling of a single, continuous 70 mm long electrode. The second utilize a segmented approach including the poling of more than 20 individual sections forming together a 70 mm long poling area with no stitching errors. While the continuous electrode allows for faster fabrication, the segmented approach allows to individually optimize the poling resulting in less duty cycle variation. A detailed analysis of the periodic poling results reveals that the results of both are consistent with previously reported poling outcomes for shorter devices. Thus, we demonstrate wafer-scale periodic poling exceeding chiplet-size without any loss in the periodic poling quality. Our work presents a key step towards highly-efficient, narrow-bandwidth and low-pump power nonlinear optical devices.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"147 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145613428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-28DOI: 10.1515/nanoph-2025-0501
Seunghyun Lee, Byounghyo Lee, Haejun Chung
Waveguide-based augmented-reality (AR) displays offer compact, optical see-through form factors but remain limited by chromatic dispersion, ghosting from parasitic diffraction orders, distortion of the see-through scene, and a restricted eyebox. We present triple-function metasurface couplers designed using adjoint-based optimization, which overcome these limitations and establish computational performance bounds. The out-coupler simultaneously preserves zeroth-order transmission of the see-through path and directs display light into designated diffraction orders while returning residual guided power as zeroth-order reflection for eyebox expansion. The in-coupler assigns distinct diffraction orders to R/G/B and equalizes their in-plane propagation angles, achieving achromatic guidance and eliminating chromatic path divergence. Quantitatively, the optimized out-coupler provides >90 % angle-averaged zeroth-order transmission for the see-through view (10–40× lower higher-order leakage) and >95 % zeroth-order guided reflection, while maintaining efficient diffractive couplings to the eyebox. PSF/MTF analyses confirm near-diffraction-limited virtual-image quality and strong suppression of see-through view distortion. Finally, benchmarking freeform against fabrication-constrained multilayer architectures (1–6 layers) shows that multilayers approach the freeform upper bound while remaining practical to fabricate. These results outline a general, manufacturable methodology for multifunctional metasurface couplers and a practical route to compact, high-quality AR waveguides.
{"title":"Optical see-through augmented reality via inverse-designed waveguide couplers","authors":"Seunghyun Lee, Byounghyo Lee, Haejun Chung","doi":"10.1515/nanoph-2025-0501","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0501","url":null,"abstract":"Waveguide-based augmented-reality (AR) displays offer compact, optical see-through form factors but remain limited by chromatic dispersion, ghosting from parasitic diffraction orders, distortion of the see-through scene, and a restricted eyebox. We present triple-function metasurface couplers designed using adjoint-based optimization, which overcome these limitations and establish computational performance bounds. The out-coupler simultaneously preserves zeroth-order transmission of the see-through path and directs display light into designated diffraction orders while returning residual guided power as zeroth-order reflection for eyebox expansion. The in-coupler assigns distinct diffraction orders to R/G/B and equalizes their in-plane propagation angles, achieving achromatic guidance and eliminating chromatic path divergence. Quantitatively, the optimized out-coupler provides >90 % angle-averaged zeroth-order transmission for the see-through view (10–40× lower higher-order leakage) and >95 % zeroth-order guided reflection, while maintaining efficient diffractive couplings to the eyebox. PSF/MTF analyses confirm near-diffraction-limited virtual-image quality and strong suppression of see-through view distortion. Finally, benchmarking freeform against fabrication-constrained multilayer architectures (1–6 layers) shows that multilayers approach the freeform upper bound while remaining practical to fabricate. These results outline a general, manufacturable methodology for multifunctional metasurface couplers and a practical route to compact, high-quality AR waveguides.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"18 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145611134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-28DOI: 10.1515/nanoph-2025-0247
Nikolas Hadjiantoni, Heedong Goh, Stephen M. Hanham, Miguel Navarro-Cía, Andrea Alù
While conventional von Neumann based machines are increasingly challenged by modern day requirements, electromagnetic analog computing devices promise to provide a platform that is highly parallel, efficient and fast. Along this paradigm, it has been shown that arrays of subwavelength electromagnetic scatterers can be used as solvers of partial differential equations. Inverse design offers a powerful tool to synthesize such analog computing machines, utilizing engineered non-local responses to produce the solution of a desired mathematical operation encoded in the scattered fields. So far, this approach has been largely restricted to linear, reciprocal scatterers, limiting its generality and applicability. Here we demonstrate how arrays of gyrotropic scatterers can be used to solve a more general class of differential equations. Through inverse design, with a combination of evolutionary and gradient based algorithms, the position of the scatterers is optimized to achieve the desired kernel response. Introducing gyrotropic media, we also demonstrate improved accuracy by >2 orders of magnitude compared to similarly sized reciprocal systems designed with the same method.
{"title":"Inverse-designed gyrotropic scatterers for non-reciprocal analog computing","authors":"Nikolas Hadjiantoni, Heedong Goh, Stephen M. Hanham, Miguel Navarro-Cía, Andrea Alù","doi":"10.1515/nanoph-2025-0247","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0247","url":null,"abstract":"While conventional von Neumann based machines are increasingly challenged by modern day requirements, electromagnetic analog computing devices promise to provide a platform that is highly parallel, efficient and fast. Along this paradigm, it has been shown that arrays of subwavelength electromagnetic scatterers can be used as solvers of partial differential equations. Inverse design offers a powerful tool to synthesize such analog computing machines, utilizing engineered non-local responses to produce the solution of a desired mathematical operation encoded in the scattered fields. So far, this approach has been largely restricted to linear, reciprocal scatterers, limiting its generality and applicability. Here we demonstrate how arrays of gyrotropic scatterers can be used to solve a more general class of differential equations. Through inverse design, with a combination of evolutionary and gradient based algorithms, the position of the scatterers is optimized to achieve the desired kernel response. Introducing gyrotropic media, we also demonstrate improved accuracy by >2 orders of magnitude compared to similarly sized reciprocal systems designed with the same method.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"29 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145611130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Combining the advantages of polydopamine (PDA), gold nanoparticles (AuNPs), and U-shaped optical fibers, a PDA/AuNPs/PDA sandwich structure modified U-shaped optical fiber surface plasmon resonance (SPR) biosensor was proposed and used for the detection of rabbit IgG. The U-shaped structure significantly enhances the penetration depth of the evanescent field. The PDA/AuNPs/PDA sandwich structure boosts coupling efficiency of SPR and LSPR, increases the specific surface area of the sensor, and improves surface activity. The experimental results show that the refractive index (RI) sensitivity of the sensor is 6,206.32 nm/RIU in the RI range of 1.3353–1.3595, which is 1.63 times higher than the raw U-shaped sensor. The biosensor for detection of rabbit IgG achieved a biosensitivity of 0.153 nm/(ng/mL), which is two orders of magnitude higher and a limit of detection (LOD) of 0.131 ng/mL, which is one order of magnitude lower. The outstanding performance of the proposed biosensor offers a new solution for the detection of low-concentration biological solutions, and it has great potential applications in the field of medical diagnosis.
{"title":"High-sensitivity U-shaped biosensor for rabbit IgG detection based on PDA/AuNPs/PDA sandwich structure","authors":"Pengxiang Chang, Yirui Zhang, Ailing Zhang, Zhen Li, Zhiyang Wang, Yanmei Shi","doi":"10.1515/nanoph-2025-0367","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0367","url":null,"abstract":"Combining the advantages of polydopamine (PDA), gold nanoparticles (AuNPs), and U-shaped optical fibers, a PDA/AuNPs/PDA sandwich structure modified U-shaped optical fiber surface plasmon resonance (SPR) biosensor was proposed and used for the detection of rabbit IgG. The U-shaped structure significantly enhances the penetration depth of the evanescent field. The PDA/AuNPs/PDA sandwich structure boosts coupling efficiency of SPR and LSPR, increases the specific surface area of the sensor, and improves surface activity. The experimental results show that the refractive index (RI) sensitivity of the sensor is 6,206.32 nm/RIU in the RI range of 1.3353–1.3595, which is 1.63 times higher than the raw U-shaped sensor. The biosensor for detection of rabbit IgG achieved a biosensitivity of 0.153 nm/(ng/mL), which is two orders of magnitude higher and a limit of detection (LOD) of 0.131 ng/mL, which is one order of magnitude lower. The outstanding performance of the proposed biosensor offers a new solution for the detection of low-concentration biological solutions, and it has great potential applications in the field of medical diagnosis.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"150 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145611115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We demonstrated a far-field super-resolution optical imaging for mapping the resonance mode within semiconductor nanowires, where periodic distributions are found with good agreement between simulation and experiment. The pronounced absorption at the antinodes leads to localized photothermal heating, as well as consequent scattering nonlinearity via the thermo-optic effect. To break the diffraction limit, we combine the scattering nonlinearity with tightly focused laser scanning. Based on the principle of saturated excitation (SAX) microscopy, the nonlinear scattering signals are extracted to significantly improve the spatial resolution (1.7 fold), enabling visualization of the resonant modes that are not visible with conventional far-field optical imaging. Our results pave the way for optical inspection of semiconductor photonic integrated circuits with subdiffraction-limit spatial resolution.
{"title":"Super-resolution imaging of resonance modes in semiconductor nanowires by detecting photothermal nonlinear scattering","authors":"Yu-An Chen, Te-Hsin Yen, Chun-Yu Yang, Jhih-Jia Chen, Chih‐Wei Chang, Kentaro Nishida, Shi-Wei Chu","doi":"10.1515/nanoph-2025-0383","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0383","url":null,"abstract":"We demonstrated a far-field super-resolution optical imaging for mapping the resonance mode within semiconductor nanowires, where periodic distributions are found with good agreement between simulation and experiment. The pronounced absorption at the antinodes leads to localized photothermal heating, as well as consequent scattering nonlinearity via the thermo-optic effect. To break the diffraction limit, we combine the scattering nonlinearity with tightly focused laser scanning. Based on the principle of saturated excitation (SAX) microscopy, the nonlinear scattering signals are extracted to significantly improve the spatial resolution (1.7 fold), enabling visualization of the resonant modes that are not visible with conventional far-field optical imaging. Our results pave the way for optical inspection of semiconductor photonic integrated circuits with subdiffraction-limit spatial resolution.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"32 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145608969","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 : 2025-11-27DOI: 10.1515/nanoph-2025-0458
Mingxiao Li, Chao Xiang, Joel Guo, Jonathan Peters, Mario Dumont, Shixin Xue, Jeremy Staffa, Qili Hu, Zhengdong Gao, Qiang Lin, John E. Bowers
We demonstrate a versatile heterogeneous integration platform unifying III–V gain with thin-film lithium niobate (TFLN) photonic circuits to create high-performance lasers with integrated functionality. This breakthrough overcomes the critical barrier to fully integrated photonic systems by combining optical gain, low-loss cavities, and phase control on a single chip. We present two distinct laser architectures: a distributed feedback laser achieving 11.0 kHz intrinsic linewidth and 4.0 mW in-fiber power through self-injection locking to a high- Q TFLN resonator, and a Vernier ring laser exhibiting 44 nm continuous tuning range with >${ >} $ 40 dB side-mode suppression ratio. Crucially, the heterogeneous integration of the gain section with TFLN’s components provides a promising path to implementing direct intracavity modulation, which is a functionality that typically requires discrete components. This inherent capability makes our platform a foundational advancement for future compact, robust systems in coherent communications, ultrafast optical metrology, quantum photonic processors, and microwave photonic systems operating at GHz bandwidths, marking a significant advancement toward complete photonic system integration.
{"title":"Heterogeneously-integrated lasers on thin film lithium niobate","authors":"Mingxiao Li, Chao Xiang, Joel Guo, Jonathan Peters, Mario Dumont, Shixin Xue, Jeremy Staffa, Qili Hu, Zhengdong Gao, Qiang Lin, John E. Bowers","doi":"10.1515/nanoph-2025-0458","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0458","url":null,"abstract":"We demonstrate a versatile heterogeneous integration platform unifying III–V gain with thin-film lithium niobate (TFLN) photonic circuits to create high-performance lasers with integrated functionality. This breakthrough overcomes the critical barrier to fully integrated photonic systems by combining optical gain, low-loss cavities, and phase control on a single chip. We present two distinct laser architectures: a distributed feedback laser achieving 11.0 kHz intrinsic linewidth and 4.0 mW in-fiber power through self-injection locking to a high- <jats:italic>Q</jats:italic> TFLN resonator, and a Vernier ring laser exhibiting 44 nm continuous tuning range with <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <m:mo>></m:mo> </m:math> <jats:tex-math>${ >} $</jats:tex-math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_nanoph-2025-0458_ineq_001.png\"/> </jats:alternatives> </jats:inline-formula> 40 dB side-mode suppression ratio. Crucially, the heterogeneous integration of the gain section with TFLN’s components provides a promising path to implementing direct intracavity modulation, which is a functionality that typically requires discrete components. This inherent capability makes our platform a foundational advancement for future compact, robust systems in coherent communications, ultrafast optical metrology, quantum photonic processors, and microwave photonic systems operating at GHz bandwidths, marking a significant advancement toward complete photonic system integration.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"236 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145608970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-26DOI: 10.1515/nanoph-2025-0379
Stefan Lichtmannecker, Santiago Echeverri-Arteaga, Michael Kaniber, Isabel C. Andrade Martelo, Joaquín Ruiz-Rivas, Thorsten Reichert, Günther Reithmaier, Per-Lennart Ardelt, Max Bichler, Eduardo Zubizarreta Casalengua, Edgar A. Gómez, Herbert Vinck-Posada, Elena del Valle, Kai Müller, Fabrice P. Laussy, Jonathan J. Finley
We study the emission from a molecular photonic cavity formed by two proximal photonic crystal defect cavities containing a small number (<3)$(< 3)$ of In(Ga)As quantum dots. Under strong excitation, we observe photoluminescence from the bonding and antibonding modes in agreement with ab initio numerical simulations. Power dependent measurements, however, reveal an unexpected peak, emerging at an energy between the bonding and antibonding modes of the molecule. Temperature-dependent measurements indicate that this unexpected feature is photonic in origin. Time-resolved measurements show the emergent peak exhibits a lifetime τM = 0.75(10) ns, similar to both bonding and antibonding coupled modes. Comparisons of experimental results with quantum optical modeling suggest that this new feature arises from a coexistence of weak and strong coupling, due to the molecule emitting in an environment whose configuration permits or, on the contrary, impedes its strong coupling. This scenario is reproduced theoretically with a master equation reduced to the key ingredients of its dynamics and that roots the mechanism to a dissipative coupling between bare modes of the system. Excellent qualitative agreement is obtained between experiment and theory, showing how solid-state cavity QED can reveal intriguing new regimes of light–matter interaction.
我们研究了由含有少量（< 3）$ (< 3)$ In(Ga)As量子点的两个近端光子晶体缺陷腔组成的分子光子腔的发射。在强激发下，我们从成键和反键模式观察到的光致发光与从头计算的数值模拟一致。然而，与功率相关的测量揭示了一个意想不到的峰值，出现在分子的成键和反键模式之间的能量处。温度相关的测量表明，这种意想不到的特征是光子的起源。时间分辨测量表明，涌现峰的寿命τ M = 0.75(10) ns，与成键和反键耦合模式相似。实验结果与量子光学模型的比较表明，由于分子在一个结构允许或相反地阻碍其强耦合的环境中发射，弱耦合和强耦合共存产生了这种新特征。这种情况在理论上被再现，主方程被简化为其动力学的关键成分，并将机制植根于系统裸模之间的耗散耦合。实验和理论之间获得了极好的定性一致性，表明固态腔QED如何揭示光-物质相互作用的有趣新制度。
{"title":"Coexistence of weak and strong coupling in a photonic molecule through dissipative coupling to a quantum dot","authors":"Stefan Lichtmannecker, Santiago Echeverri-Arteaga, Michael Kaniber, Isabel C. Andrade Martelo, Joaquín Ruiz-Rivas, Thorsten Reichert, Günther Reithmaier, Per-Lennart Ardelt, Max Bichler, Eduardo Zubizarreta Casalengua, Edgar A. Gómez, Herbert Vinck-Posada, Elena del Valle, Kai Müller, Fabrice P. Laussy, Jonathan J. Finley","doi":"10.1515/nanoph-2025-0379","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0379","url":null,"abstract":"We study the emission from a molecular photonic cavity formed by two proximal photonic crystal defect cavities containing a small number <jats:inline-formula> <jats:alternatives> <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <m:mrow> <m:mo stretchy=\"false\">(</m:mo> <m:mrow> <m:mo><</m:mo> <m:mn>3</m:mn> </m:mrow> <m:mo stretchy=\"false\">)</m:mo> </m:mrow> </m:math> <jats:tex-math>$(< 3)$</jats:tex-math> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_nanoph-2025-0379_ineq_001.png\"/> </jats:alternatives> </jats:inline-formula> of In(Ga)As quantum dots. Under strong excitation, we observe photoluminescence from the bonding and antibonding modes in agreement with ab initio numerical simulations. Power dependent measurements, however, reveal an unexpected peak, emerging at an energy between the bonding and antibonding modes of the molecule. Temperature-dependent measurements indicate that this unexpected feature is photonic in origin. Time-resolved measurements show the emergent peak exhibits a lifetime <jats:italic>τ</jats:italic> <jats:sub>M</jats:sub> = 0.75(10) ns, similar to both bonding and antibonding coupled modes. Comparisons of experimental results with quantum optical modeling suggest that this new feature arises from a coexistence of weak and strong coupling, due to the molecule emitting in an environment whose configuration permits or, on the contrary, impedes its strong coupling. This scenario is reproduced theoretically with a master equation reduced to the key ingredients of its dynamics and that roots the mechanism to a dissipative coupling between bare modes of the system. Excellent qualitative agreement is obtained between experiment and theory, showing how solid-state cavity QED can reveal intriguing new regimes of light–matter interaction.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"150 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145599200","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 : 2025-11-26DOI: 10.1515/nanoph-2025-0340
Han Xue, Chukun Huang, Haotian Shi, Jiaheng Fu, Tianheng Zhang, Junqiang Sun
Aluminum nitride (AlN), a wide-bandgap III–V material, offers excellent transparency in the optical communication band and a favorable refractive index for strong optical confinement, making it a promising platform in stimulated Brillouin scattering (SBS). Here, we observe, for the first time, optically excited SBS in suspended AlN-on-silicon waveguides. A Brillouin gain coefficient of 91.8 m −1 W −1 is achieved at an acoustic frequency of 2.32 GHz, with a linewidth of 10.1 MHz. The Brillouin nonlinear response can be tailored by varying the waveguide dimensions. Furthermore, the Bragg grating–based Fabry–Pérot (FP) resonator enhances the gain coefficient to 150.37 m −1 W −1 and results in a narrowed linewidth of 9.87 MHz. These results not only validate the feasibility of strong intrinsic Brillouin interaction in suspended AlN waveguides but also pave the new way for CMOS-compatible on-chip Brillouin amplifiers, lasers, and isolators.
{"title":"Intramodal stimulated Brillouin scattering in suspended AlN waveguides","authors":"Han Xue, Chukun Huang, Haotian Shi, Jiaheng Fu, Tianheng Zhang, Junqiang Sun","doi":"10.1515/nanoph-2025-0340","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0340","url":null,"abstract":"Aluminum nitride (AlN), a wide-bandgap III–V material, offers excellent transparency in the optical communication band and a favorable refractive index for strong optical confinement, making it a promising platform in stimulated Brillouin scattering (SBS). Here, we observe, for the first time, optically excited SBS in suspended AlN-on-silicon waveguides. A Brillouin gain coefficient of 91.8 m <jats:sup>−1</jats:sup> W <jats:sup>−1</jats:sup> is achieved at an acoustic frequency of 2.32 GHz, with a linewidth of 10.1 MHz. The Brillouin nonlinear response can be tailored by varying the waveguide dimensions. Furthermore, the Bragg grating–based Fabry–Pérot (FP) resonator enhances the gain coefficient to 150.37 m <jats:sup>−1</jats:sup> W <jats:sup>−1</jats:sup> and results in a narrowed linewidth of 9.87 MHz. These results not only validate the feasibility of strong intrinsic Brillouin interaction in suspended AlN waveguides but also pave the new way for CMOS-compatible on-chip Brillouin amplifiers, lasers, and isolators.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"674 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145599198","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 : 2025-11-26DOI: 10.1515/nanoph-2025-0467
Seojoo Lee, Ji-Hun Kang
We propose two-dimensional (2D) in-plane heterostructures, composed of a 2D crystal adjoining a perfect electric conductor (PEC) plane, that enable ultranarrow polaritonic resonant cavities. Specifically, we theoretically investigate the interaction of 2D surface polaritons (2DSPs) with the junction between the 2D crystal and a PEC plane. We reveal that when 2DSPs are strongly confined, the reflected 2DSPs experience a phase shift of 3 π /4, which exhibits π /2 deviation from the so-called edge reflection value. This non-trivial phase shift is shown to play a crucial role in enabling resonant cavities whose size can be far smaller than the wavelength of the 2DSPs. Furthermore, we demonstrate that the spatial dimensionality of our heterostructure allows a direct mapping to metasurface-based heterostructures, where the 2D crystal is replaced by a metasurface supporting spoof surface polaritons (SSPs). This correspondence extends the feasibility of our concept to SSP-based resonators and broadens the accessible frequency range into the terahertz and microwave regimes. Our work provides not only deeper insight into low-dimensional polariton optics but also a design strategy for ultracompact polaritonic metaresonators.
{"title":"Ultranarrow polaritonic cavities formed by one-dimensional junctions of two-dimensional in-plane heterostructures","authors":"Seojoo Lee, Ji-Hun Kang","doi":"10.1515/nanoph-2025-0467","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0467","url":null,"abstract":"We propose two-dimensional (2D) in-plane heterostructures, composed of a 2D crystal adjoining a perfect electric conductor (PEC) plane, that enable ultranarrow polaritonic resonant cavities. Specifically, we theoretically investigate the interaction of 2D surface polaritons (2DSPs) with the junction between the 2D crystal and a PEC plane. We reveal that when 2DSPs are strongly confined, the reflected 2DSPs experience a phase shift of 3 <jats:italic>π</jats:italic> /4, which exhibits <jats:italic>π</jats:italic> /2 deviation from the so-called edge reflection value. This non-trivial phase shift is shown to play a crucial role in enabling resonant cavities whose size can be far smaller than the wavelength of the 2DSPs. Furthermore, we demonstrate that the spatial dimensionality of our heterostructure allows a direct mapping to metasurface-based heterostructures, where the 2D crystal is replaced by a metasurface supporting spoof surface polaritons (SSPs). This correspondence extends the feasibility of our concept to SSP-based resonators and broadens the accessible frequency range into the terahertz and microwave regimes. Our work provides not only deeper insight into low-dimensional polariton optics but also a design strategy for ultracompact polaritonic metaresonators.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"220 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145599199","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 : 2025-11-25DOI: 10.1515/nanoph-2025-0418
Soh Uenoyama, Yusuke Yoshizawa, Kazunori Tanaka, Hiroyasu Fujiwara, Atsushi Ono
Silicon-based photodetectors operating in the near-infrared (NIR) wavelength range ( λ = 700–1,100 nm) are essential for applications such as light detection and ranging, facial recognition, and eye-tracking. However, silicon’s low absorption coefficient in this range limits photodetection efficiency. While recent advances in nano-diffraction structures have improved photo-absorption by increasing the effective absorption path, optimizing carrier dynamics remains challenging. In the NIR regime, photons penetrate deeply into the silicon substrate, making it critical to align the spatial distribution of photo-generated carriers with the charge collection regions. However, the angular and spatial behavior of carrier generation (CG) and collection under nano-diffraction structures remain underexplored. This study presents an analytical model that visualizes CG pathways and corresponding collection probabilities induced by plasmonic diffraction structures, providing insight into diffraction-driven CG in silicon. The model is experimentally validated through photocurrent responses in non-illuminated neighboring pixels, directly revealing plasmonic diffraction effects. The results show that diffraction enhances light absorption and enables visualization of the CG and collection pathways based on the diffraction angle. This approach enables the spatial overlap of CG and collection pathways, efficiently guiding incident photons to photosensitive regions. This framework offers a new strategy to enhance NIR photodetector performance through diffraction-guided light propagation and device-specific modeling.
{"title":"Visualization of plasmonic diffraction-guided carrier dynamics in silicon photodetectors","authors":"Soh Uenoyama, Yusuke Yoshizawa, Kazunori Tanaka, Hiroyasu Fujiwara, Atsushi Ono","doi":"10.1515/nanoph-2025-0418","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0418","url":null,"abstract":"Silicon-based photodetectors operating in the near-infrared (NIR) wavelength range ( <jats:italic>λ</jats:italic> = 700–1,100 nm) are essential for applications such as light detection and ranging, facial recognition, and eye-tracking. However, silicon’s low absorption coefficient in this range limits photodetection efficiency. While recent advances in nano-diffraction structures have improved photo-absorption by increasing the effective absorption path, optimizing carrier dynamics remains challenging. In the NIR regime, photons penetrate deeply into the silicon substrate, making it critical to align the spatial distribution of photo-generated carriers with the charge collection regions. However, the angular and spatial behavior of carrier generation (CG) and collection under nano-diffraction structures remain underexplored. This study presents an analytical model that visualizes CG pathways and corresponding collection probabilities induced by plasmonic diffraction structures, providing insight into diffraction-driven CG in silicon. The model is experimentally validated through photocurrent responses in non-illuminated neighboring pixels, directly revealing plasmonic diffraction effects. The results show that diffraction enhances light absorption and enables visualization of the CG and collection pathways based on the diffraction angle. This approach enables the spatial overlap of CG and collection pathways, efficiently guiding incident photons to photosensitive regions. This framework offers a new strategy to enhance NIR photodetector performance through diffraction-guided light propagation and device-specific modeling.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"16 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145592930","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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