Pub Date : 2026-02-03DOI: 10.1038/s41566-025-01837-4
Haoran Chen, Ruxuan Liu, Gedalia Y. Koehler, Fatemehsadat Tabatabaei, Xiangwen Guo, Shuman Sun, Zijiao Yang, Beichen Wang, Andreas Beling, Xu Yi
Integrated photonics has undergone tremendous development in the past few decades. Loss and gain are two fundamental parameters in photonic integrated circuits (PICs) and have direct impacts on nearly all key performance metrics. Surprisingly, the tools to characterize the optical loss and gain inside PICs are very limited. This is because, unlike free-space or fibre optics, integrated circuits cannot be non-destructively disassembled. Here we report a universal method to see inside the PICs and measure loss and gain on the component level non-destructively. The method leverages nonlinear optical devices as optical power discriminators to retrieve the loss and gain information. Our method has a precision better than 0.1 dB and can characterize the loss of individual fibre–chip coupling facets as well as general unknown devices under test. As an application, we measured the true on-chip quantum efficiency of a quantum PIC consisting of heterogeneously integrated balanced photodiodes, a critical building block for integrated quantum technology. Our non-destructive and highly precise method can be implemented on different photonic platforms to understand gain and loss in complex photonic circuits, which is essential to optimize circuit design and to create large-scale systems with predictable, reproducible performance.
{"title":"Universal loss and gain characterization inside photonic integrated circuits","authors":"Haoran Chen, Ruxuan Liu, Gedalia Y. Koehler, Fatemehsadat Tabatabaei, Xiangwen Guo, Shuman Sun, Zijiao Yang, Beichen Wang, Andreas Beling, Xu Yi","doi":"10.1038/s41566-025-01837-4","DOIUrl":"https://doi.org/10.1038/s41566-025-01837-4","url":null,"abstract":"Integrated photonics has undergone tremendous development in the past few decades. Loss and gain are two fundamental parameters in photonic integrated circuits (PICs) and have direct impacts on nearly all key performance metrics. Surprisingly, the tools to characterize the optical loss and gain inside PICs are very limited. This is because, unlike free-space or fibre optics, integrated circuits cannot be non-destructively disassembled. Here we report a universal method to see inside the PICs and measure loss and gain on the component level non-destructively. The method leverages nonlinear optical devices as optical power discriminators to retrieve the loss and gain information. Our method has a precision better than 0.1 dB and can characterize the loss of individual fibre–chip coupling facets as well as general unknown devices under test. As an application, we measured the true on-chip quantum efficiency of a quantum PIC consisting of heterogeneously integrated balanced photodiodes, a critical building block for integrated quantum technology. Our non-destructive and highly precise method can be implemented on different photonic platforms to understand gain and loss in complex photonic circuits, which is essential to optimize circuit design and to create large-scale systems with predictable, reproducible performance.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":"5 1","pages":""},"PeriodicalIF":35.0,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2026-02-02DOI: 10.1038/s41566-025-01840-9
Jesús Yelo-Sarrión, François Leo, Simon-Pierre Gorza
The generation of optically coherent ultrashort pulses by mode-locked lasers has revolutionized advancements in modern science and technology. These pulses often arise from the formation of dissipative solitons, which emerge due to a balance between energy excitation and dissipation. Harnessing the concept of parity–time (PT) symmetry to control this balance, we demonstrate a new type of laser dissipative soliton hosted in linearly coupled ring cavities. Our experiments are performed in a laser where the linear hybridized modes are in the PT-symmetric phase. Here we experimentally observe the formation of short pulses, stabilized by the selective breaking of the PT symmetry by Kerr nonlinearity. Our results unlock new possibilities for passive mode-locking by demonstrating spontaneous pulse formation in PT-symmetric lasers, which hold the potential for simple cavity designs.
{"title":"Dissipative solitons in mode-locked parity–time-symmetric lasers","authors":"Jesús Yelo-Sarrión, François Leo, Simon-Pierre Gorza","doi":"10.1038/s41566-025-01840-9","DOIUrl":"https://doi.org/10.1038/s41566-025-01840-9","url":null,"abstract":"The generation of optically coherent ultrashort pulses by mode-locked lasers has revolutionized advancements in modern science and technology. These pulses often arise from the formation of dissipative solitons, which emerge due to a balance between energy excitation and dissipation. Harnessing the concept of parity–time (PT) symmetry to control this balance, we demonstrate a new type of laser dissipative soliton hosted in linearly coupled ring cavities. Our experiments are performed in a laser where the linear hybridized modes are in the PT-symmetric phase. Here we experimentally observe the formation of short pulses, stabilized by the selective breaking of the PT symmetry by Kerr nonlinearity. Our results unlock new possibilities for passive mode-locking by demonstrating spontaneous pulse formation in PT-symmetric lasers, which hold the potential for simple cavity designs.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":"8 1","pages":""},"PeriodicalIF":35.0,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2026-01-26DOI: 10.1038/s41566-025-01833-8
Emanuele Galiffi, Anthony C. Harwood, Stefano Vezzoli, Romain Tirole, Andrea Alù, Riccardo Sapienza
Time-invariant photonic structures amplify or absorb light on the basis of their intrinsic material gain or loss. The coherent interference of multiple beams in space, for example, in a resonator, can be exploited to tailor the wave interaction with material gain or loss, respectively maximizing lasing or coherent perfect absorption. By contrast, a time-varying system is not bound to conserve energy, even in the absence of material gain or loss, and can support amplification or absorption of a probe wave through parametric phenomena. Here we demonstrate theoretically and experimentally how a subwavelength film of indium tin oxide, whose bulk permittivity is homogeneously and periodically modulated via optical pumping, can be dynamically tuned to act both as a non-resonant amplifier and as a perfect absorber, by manipulating the relative phase of two counterpropagating probe beams. This extends the concept of coherent perfect absorption to the temporal domain. We interpret this result as selective switching between the gain and loss modes present in the momentum bandgap of a periodically modulated medium. By tailoring the relative intensity of the two probes, high-contrast modulation can be achieved with up to 80% absorption and 400% amplification. Our results demonstrate control of gain and loss in time-varying media at optical frequencies and pave the way towards coherent manipulation of light in Floquet-engineered complex photonic systems. The researchers show that a subwavelength film of indium tin oxide, the bulk permittivity of which is strategically modulated via optical pumping, can be dynamically tuned to act as both a non-resonant amplifier and a perfect absorber. The findings extend the concept of coherent perfect absorption to the temporal domain and may enable coherent manipulation of light in Floquet-engineered complex photonic systems.
{"title":"Optical coherent perfect absorption and amplification in a time-varying medium","authors":"Emanuele Galiffi, Anthony C. Harwood, Stefano Vezzoli, Romain Tirole, Andrea Alù, Riccardo Sapienza","doi":"10.1038/s41566-025-01833-8","DOIUrl":"10.1038/s41566-025-01833-8","url":null,"abstract":"Time-invariant photonic structures amplify or absorb light on the basis of their intrinsic material gain or loss. The coherent interference of multiple beams in space, for example, in a resonator, can be exploited to tailor the wave interaction with material gain or loss, respectively maximizing lasing or coherent perfect absorption. By contrast, a time-varying system is not bound to conserve energy, even in the absence of material gain or loss, and can support amplification or absorption of a probe wave through parametric phenomena. Here we demonstrate theoretically and experimentally how a subwavelength film of indium tin oxide, whose bulk permittivity is homogeneously and periodically modulated via optical pumping, can be dynamically tuned to act both as a non-resonant amplifier and as a perfect absorber, by manipulating the relative phase of two counterpropagating probe beams. This extends the concept of coherent perfect absorption to the temporal domain. We interpret this result as selective switching between the gain and loss modes present in the momentum bandgap of a periodically modulated medium. By tailoring the relative intensity of the two probes, high-contrast modulation can be achieved with up to 80% absorption and 400% amplification. Our results demonstrate control of gain and loss in time-varying media at optical frequencies and pave the way towards coherent manipulation of light in Floquet-engineered complex photonic systems. The researchers show that a subwavelength film of indium tin oxide, the bulk permittivity of which is strategically modulated via optical pumping, can be dynamically tuned to act as both a non-resonant amplifier and a perfect absorber. The findings extend the concept of coherent perfect absorption to the temporal domain and may enable coherent manipulation of light in Floquet-engineered complex photonic systems.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":"20 2","pages":"163-169"},"PeriodicalIF":32.9,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146048273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2026-01-22DOI: 10.1038/s41566-026-01852-z
Guixiang Li, Zuhong Zhang, Benjamin Agyei-Tuffour, Luyan Wu, Thomas W. Gries, Karunanantharajah Prashanthan, Lennart Frohloff, Artem Musiienko, Jinzhao Li, Rui Zhu, Lucy J. F. Hart, Luyao Wang, Zhe Li, Bo Hou, Norbert Koch, Michele Saba, Piers R. F. Barnes, Jenny Nelson, Paul J. Dyson, Mohammad Khaja Nazeeruddin, Meng Li, Antonio Abate
{"title":"Author Correction: Stabilizing high-efficiency perovskite solar cells via strategic interfacial contact engineering","authors":"Guixiang Li, Zuhong Zhang, Benjamin Agyei-Tuffour, Luyan Wu, Thomas W. Gries, Karunanantharajah Prashanthan, Lennart Frohloff, Artem Musiienko, Jinzhao Li, Rui Zhu, Lucy J. F. Hart, Luyao Wang, Zhe Li, Bo Hou, Norbert Koch, Michele Saba, Piers R. F. Barnes, Jenny Nelson, Paul J. Dyson, Mohammad Khaja Nazeeruddin, Meng Li, Antonio Abate","doi":"10.1038/s41566-026-01852-z","DOIUrl":"10.1038/s41566-026-01852-z","url":null,"abstract":"","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":"20 2","pages":"241-241"},"PeriodicalIF":32.9,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41566-026-01852-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-19DOI: 10.1038/s41566-025-01817-8
Wenhan Yang, Xin Guan, Qingbin Cai, Yuexin Lin, Zuhong Zhang, Jinbo Zhao, Jia Guo, Annan Zhu, Fenqi Du, Wenjing Zhu, Jin Liu, Sen Jiang, Nan Zhang, Xiaolong Liu, Lei Zhang, Youshen Wu, Shengchun Yang, Meng Li, Chao Liang
Molecular selective contacts are promising for increasing the power conversion efficiency of perovskite solar cells. Although highly conjugated and rigid hole-selective contacts with ordered π–π stacking facilitate efficient carrier transport, the strong intermolecular interactions responsible for such stacking also trigger molecular aggregation, compromising the homogeneity of the contact and, therefore, operational stability. Here we report a molecular contact featuring an axially chiral framework through a non-coplanar arrangement of the two π-systems and restricted N–C rotation. With an extremely low isomerization barrier of 4.37 kcal mol−1, the molecule exhibits suppressed aggregation and promotes uniform packing, yielding a homogeneous and stable interface. Devices incorporating this molecular contact delivered a power conversion efficiency of 26.91% (certified, 26.44%) and 22.14% for aperture areas of 0.08 cm2 and 69 cm2 (modules), respectively. The small-area devices achieve a T98 lifetime of over 2,000 h under continuous 1-sun maximum power point operation at 65 °C. A non-coplanar axially chiral molecular contact favours the crystalline growth of perovskite film and improves interfacial stability in perovskite solar cells. Small-area devices yield a certified power conversion efficiency of 26.44% and maintain 98% of it after 2,000 hours of operation.
{"title":"Axially chiral molecular contacts with low isomerization barriers for perovskite solar cells","authors":"Wenhan Yang, Xin Guan, Qingbin Cai, Yuexin Lin, Zuhong Zhang, Jinbo Zhao, Jia Guo, Annan Zhu, Fenqi Du, Wenjing Zhu, Jin Liu, Sen Jiang, Nan Zhang, Xiaolong Liu, Lei Zhang, Youshen Wu, Shengchun Yang, Meng Li, Chao Liang","doi":"10.1038/s41566-025-01817-8","DOIUrl":"10.1038/s41566-025-01817-8","url":null,"abstract":"Molecular selective contacts are promising for increasing the power conversion efficiency of perovskite solar cells. Although highly conjugated and rigid hole-selective contacts with ordered π–π stacking facilitate efficient carrier transport, the strong intermolecular interactions responsible for such stacking also trigger molecular aggregation, compromising the homogeneity of the contact and, therefore, operational stability. Here we report a molecular contact featuring an axially chiral framework through a non-coplanar arrangement of the two π-systems and restricted N–C rotation. With an extremely low isomerization barrier of 4.37 kcal mol−1, the molecule exhibits suppressed aggregation and promotes uniform packing, yielding a homogeneous and stable interface. Devices incorporating this molecular contact delivered a power conversion efficiency of 26.91% (certified, 26.44%) and 22.14% for aperture areas of 0.08 cm2 and 69 cm2 (modules), respectively. The small-area devices achieve a T98 lifetime of over 2,000 h under continuous 1-sun maximum power point operation at 65 °C. A non-coplanar axially chiral molecular contact favours the crystalline growth of perovskite film and improves interfacial stability in perovskite solar cells. Small-area devices yield a certified power conversion efficiency of 26.44% and maintain 98% of it after 2,000 hours of operation.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":"20 2","pages":"232-240"},"PeriodicalIF":32.9,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146006139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Self-assembled monolayers (SAMs) play an important role in improving the performance of inverted perovskite solar cells. However, loose molecular packing, non-uniform coverage, weak affinity with the solvents of perovskite precursors, and energy-level mismatch cause energy losses at the buried interface. Here we develop a light-stable donor–acceptor interface formed by an asymmetric carbazole-based SAM, namely, BrAs, and N-hydroxyethyl phthalimide (PIE). The single-side electron-withdrawing bromine in BrAs maintains wettability and reduces the valence band offset to 0.09 eV. Additionally, the asymmetric dipole in BrAs reorients the carbazole units and strengthens short-range Coulomb interactions, resulting in close packing and uniform coverage of SAMs for efficient and uniform carrier transport. The donor–acceptor interface also promotes ultrafast energy transfer, which enhances the photostability of BrAs and improves thermal carrier extraction by 19%, further minimizing energy losses. In particular, the lattice-matching PIE molecules stabilize the (100) out-of-plane orientation of the perovskite by interlocking [PbI6]4⁻ octahedra, which releases compressive stress and stabilizes the buried interface. As a result, BrAs–PIE devices achieve a power conversion efficiency of 27.28% (certified, 27.19%) and retain over 95% of the initial efficiency after 1,500 h of illumination under the ISOS-L-2 protocol.
自组装单层膜（SAMs）在提高倒置钙钛矿太阳能电池的性能方面发挥着重要作用。然而，由于分子堆积松散、覆盖不均匀、与钙钛矿前驱体溶剂亲和力弱以及能级失配等原因，导致了埋藏界面处的能量损失。在这里，我们开发了一种光稳定的供体-受体界面，由不对称的咔唑基SAM（即bra）和n -羟乙基酞酰亚胺（PIE）形成。bra中的单侧吸电子溴保持了润湿性，并将价带偏移减小到0.09 eV。此外，bra中的不对称偶极子使咔唑单元重新定向，并加强了短程库仑相互作用，从而导致sam的紧密堆积和均匀覆盖，从而实现高效和均匀的载流子传输。供体-受体界面还促进了超快的能量传递，从而提高了bra的光稳定性，并将热载流子提取率提高了19%，进一步减少了能量损失。特别是，晶格匹配的PIE分子通过联锁[PbI6]4 -八面体来稳定钙钛矿的（100）面外取向，释放压应力，稳定埋藏界面。结果，bra - pie器件的功率转换效率达到27.28%（认证为27.19%），并且在iso - l -2协议下照明1500小时后保持95%以上的初始效率。
{"title":"Photostable donor–acceptor interface for minimizing energy loss in inverted perovskite solar cells","authors":"Congcong Tian, Anxin Sun, Jinling Chen, Rongshan Zhuang, Chen Chen, Jiawei Zheng, Shuo Liu, Jiajun Du, Qianwen Chen, Lei Cai, Shulin Han, Feng Tian, Chun-Chao Chen","doi":"10.1038/s41566-025-01827-6","DOIUrl":"https://doi.org/10.1038/s41566-025-01827-6","url":null,"abstract":"Self-assembled monolayers (SAMs) play an important role in improving the performance of inverted perovskite solar cells. However, loose molecular packing, non-uniform coverage, weak affinity with the solvents of perovskite precursors, and energy-level mismatch cause energy losses at the buried interface. Here we develop a light-stable donor–acceptor interface formed by an asymmetric carbazole-based SAM, namely, BrAs, and N-hydroxyethyl phthalimide (PIE). The single-side electron-withdrawing bromine in BrAs maintains wettability and reduces the valence band offset to 0.09 eV. Additionally, the asymmetric dipole in BrAs reorients the carbazole units and strengthens short-range Coulomb interactions, resulting in close packing and uniform coverage of SAMs for efficient and uniform carrier transport. The donor–acceptor interface also promotes ultrafast energy transfer, which enhances the photostability of BrAs and improves thermal carrier extraction by 19%, further minimizing energy losses. In particular, the lattice-matching PIE molecules stabilize the (100) out-of-plane orientation of the perovskite by interlocking [PbI6]4⁻ octahedra, which releases compressive stress and stabilizes the buried interface. As a result, BrAs–PIE devices achieve a power conversion efficiency of 27.28% (certified, 27.19%) and retain over 95% of the initial efficiency after 1,500 h of illumination under the ISOS-L-2 protocol.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":"81 1","pages":""},"PeriodicalIF":35.0,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145968813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2026-01-13DOI: 10.1038/s41566-025-01832-9
Margot Niels, Tom Vanackere, Ewoud Vissers, Tingting Zhai, Patrick Nenezic, Jakob Declercq, Cédric Bruynsteen, Shengpu Niu, Arno Moerman, Olivier Caytan, Nishant Singh, Sam Lemey, Xin Yin, Sofie Janssen, Peter Verheyen, Neha Singh, Dieter Bode, Martin Davi, Filippo Ferraro, Philippe Absil, Sadhishkumar Balakrishnan, Joris Van Campenhout, Günther Roelkens, Bart Kuyken, Maximilien Billet
The rapid expansion of cloud computing and artificial intelligence has driven the demand for faster optical components in data centres to unprecedented levels. A key advancement in this field is the integration of multiple photonic components onto a single chip, enhancing the performance of optical transceivers. Here silicon photonics, benefiting from mature fabrication processes, has gained prominence in both academic research and industrial applications. The platform combines modulators, switches, photodetectors and low-loss waveguides on a single chip. However, emerging telecommunication standards require modulation speeds that exceed the capabilities of silicon-based modulators. To address these limitations, thin-film lithium niobate has been proposed as an alternative to silicon photonics, offering a low voltage–length product and exceptional high-speed modulation properties. More recently, the first demonstrations of thin-film lithium tantalate circuits have emerged, potentially addressing some of the disadvantages of lithium niobate, enabling a reduced bias drift and enhanced resistance to optical damage. As such, this material arises as a promising candidate for next-generation photonic platforms. However, a persistent drawback of such platforms is the lithium contamination, which complicates integration with CMOS fabrication processes. Here we present for the first time the integration of lithium tantalate onto a silicon photonics chip. This integration is achieved without modifying the standard silicon photonics process design kit. Our device achieves low half-wave voltage (3.5 V), low insertion loss (2.9 dB) and high-speed operation (>70 GHz), paving the way for next-generation applications. By minimizing lithium tantalate material use, our approach reduces costs while leveraging existing silicon photonics technology advancements, in particular supporting ultra-fast monolithic germanium photodetectors and established process design kits. Lithium tantalate is heterogeneously integrated with silicon photonic integrated circuits via a micro-transfer printing process in a manner fully compatible with existing workflows. A Mach–Zehnder modulator with an insertion loss of 2.9 dB and 70 GHz operation is demonstrated.
{"title":"A high-speed heterogeneous lithium tantalate silicon photonics platform","authors":"Margot Niels, Tom Vanackere, Ewoud Vissers, Tingting Zhai, Patrick Nenezic, Jakob Declercq, Cédric Bruynsteen, Shengpu Niu, Arno Moerman, Olivier Caytan, Nishant Singh, Sam Lemey, Xin Yin, Sofie Janssen, Peter Verheyen, Neha Singh, Dieter Bode, Martin Davi, Filippo Ferraro, Philippe Absil, Sadhishkumar Balakrishnan, Joris Van Campenhout, Günther Roelkens, Bart Kuyken, Maximilien Billet","doi":"10.1038/s41566-025-01832-9","DOIUrl":"10.1038/s41566-025-01832-9","url":null,"abstract":"The rapid expansion of cloud computing and artificial intelligence has driven the demand for faster optical components in data centres to unprecedented levels. A key advancement in this field is the integration of multiple photonic components onto a single chip, enhancing the performance of optical transceivers. Here silicon photonics, benefiting from mature fabrication processes, has gained prominence in both academic research and industrial applications. The platform combines modulators, switches, photodetectors and low-loss waveguides on a single chip. However, emerging telecommunication standards require modulation speeds that exceed the capabilities of silicon-based modulators. To address these limitations, thin-film lithium niobate has been proposed as an alternative to silicon photonics, offering a low voltage–length product and exceptional high-speed modulation properties. More recently, the first demonstrations of thin-film lithium tantalate circuits have emerged, potentially addressing some of the disadvantages of lithium niobate, enabling a reduced bias drift and enhanced resistance to optical damage. As such, this material arises as a promising candidate for next-generation photonic platforms. However, a persistent drawback of such platforms is the lithium contamination, which complicates integration with CMOS fabrication processes. Here we present for the first time the integration of lithium tantalate onto a silicon photonics chip. This integration is achieved without modifying the standard silicon photonics process design kit. Our device achieves low half-wave voltage (3.5 V), low insertion loss (2.9 dB) and high-speed operation (>70 GHz), paving the way for next-generation applications. By minimizing lithium tantalate material use, our approach reduces costs while leveraging existing silicon photonics technology advancements, in particular supporting ultra-fast monolithic germanium photodetectors and established process design kits. Lithium tantalate is heterogeneously integrated with silicon photonic integrated circuits via a micro-transfer printing process in a manner fully compatible with existing workflows. A Mach–Zehnder modulator with an insertion loss of 2.9 dB and 70 GHz operation is demonstrated.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":"20 2","pages":"225-231"},"PeriodicalIF":32.9,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2026-01-12DOI: 10.1038/s41566-025-01825-8
Wenhao Wang, Yi Ji Tan, Pascal Szriftgiser, Guillaume Ducournau, Ranjan Singh
The rise of topological valley photonics heralds a new era in photonic integrated circuits featuring low-loss, compact designs with robust light transport through sharp corners. However, most demonstrations of valley photonic devices only focus on the robust waveguiding of light with suppressed radiation leakage. Here we harness the conical radiation of leaky valley photonic crystals to demonstrate a topological leaky-wave antenna (LWA) that unifies leaky and guided topological edge states on a single silicon chip. We demonstrate a wide-range beam scanning of 120° in the polar angle with a maximum gain of 15 dBi using a single-branch topological LWA. In addition, the 3-branch LWA enables beam scanning over 75% of the entire three-dimensional solid-angle space. We further demonstrate frequency-division demultiplexing of 3 terahertz wireless links, each radiating 120° apart to collectively deliver high-gain omnidirectional full-space coverage, achieving an aggregate data rate of 72 Gbps. Furthermore, we demonstrate bidirectional dual-channel terahertz wireless links, where the time-reversal-symmetric topological LWA simultaneously receives a real-time high-definition video stream and transmits on-chip signals into free space at a data rate of 24 Gbps. Our on-chip leaky topological antennas provide a versatile platform for the next generation 6G and beyond (XG) cellular networks, imaging, terahertz Wi-Fi (TeraFi), and terahertz detection and ranging (TeDAR).
{"title":"On-chip topological leaky-wave antenna for full-space terahertz wireless connectivity","authors":"Wenhao Wang, Yi Ji Tan, Pascal Szriftgiser, Guillaume Ducournau, Ranjan Singh","doi":"10.1038/s41566-025-01825-8","DOIUrl":"https://doi.org/10.1038/s41566-025-01825-8","url":null,"abstract":"The rise of topological valley photonics heralds a new era in photonic integrated circuits featuring low-loss, compact designs with robust light transport through sharp corners. However, most demonstrations of valley photonic devices only focus on the robust waveguiding of light with suppressed radiation leakage. Here we harness the conical radiation of leaky valley photonic crystals to demonstrate a topological leaky-wave antenna (LWA) that unifies leaky and guided topological edge states on a single silicon chip. We demonstrate a wide-range beam scanning of 120° in the polar angle with a maximum gain of 15 dBi using a single-branch topological LWA. In addition, the 3-branch LWA enables beam scanning over 75% of the entire three-dimensional solid-angle space. We further demonstrate frequency-division demultiplexing of 3 terahertz wireless links, each radiating 120° apart to collectively deliver high-gain omnidirectional full-space coverage, achieving an aggregate data rate of 72 Gbps. Furthermore, we demonstrate bidirectional dual-channel terahertz wireless links, where the time-reversal-symmetric topological LWA simultaneously receives a real-time high-definition video stream and transmits on-chip signals into free space at a data rate of 24 Gbps. Our on-chip leaky topological antennas provide a versatile platform for the next generation 6G and beyond (XG) cellular networks, imaging, terahertz Wi-Fi (TeraFi), and terahertz detection and ranging (TeDAR).","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":"124 1","pages":""},"PeriodicalIF":35.0,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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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