Pub Date : 2026-03-20DOI: 10.1021/acsphotonics.5c02676
Kirill Khabarov, Ilaria Micol Baldi, Maria Blanco Formoso, Foroogh Khozeymeh Sarbishe, Veronica Storari, Federica Villa, Francesco Difato, Francesco Tantussi, Francesco De Angelis
Peptides are key biomolecules in biology and medicine, yet their reliable detection and discrimination in complex mixtures remain highly challenging, particularly under clinical requirements of robustness and accuracy. Surface-enhanced Raman spectroscopy (SERS) offers molecular specificity but is hindered by spectral overlap, variability, and fluctuations that limit its applicability in practical settings. In this work, we investigate the performance of SERS flow-through strategy using plasmonic nanopores to record Raman spectra from single molecules as they translocate one by one through sub-2 nm hotspots. As a stringent test, we investigated the discrimination of vasopressin and oxytocin, two peptides differing by only two amino acids. Using electrophoretic delivery and ultrafast SERS detection with a single-photon avalanche diode camera, we captured spectra on microsecond time scales. Machine-learning analysis achieved 70.5% classification accuracy at the single-peptide level, rising to 99% discrimination when averaging 40 events. These results establish flow-through nanopore SERS as a promising route toward single-molecule peptide identification in biomedical settings.
{"title":"Single-Molecule Peptide Discrimination via Flow-Through SERS and Machine Learning","authors":"Kirill Khabarov, Ilaria Micol Baldi, Maria Blanco Formoso, Foroogh Khozeymeh Sarbishe, Veronica Storari, Federica Villa, Francesco Difato, Francesco Tantussi, Francesco De Angelis","doi":"10.1021/acsphotonics.5c02676","DOIUrl":"https://doi.org/10.1021/acsphotonics.5c02676","url":null,"abstract":"Peptides are key biomolecules in biology and medicine, yet their reliable detection and discrimination in complex mixtures remain highly challenging, particularly under clinical requirements of robustness and accuracy. Surface-enhanced Raman spectroscopy (SERS) offers molecular specificity but is hindered by spectral overlap, variability, and fluctuations that limit its applicability in practical settings. In this work, we investigate the performance of SERS flow-through strategy using plasmonic nanopores to record Raman spectra from single molecules as they translocate one by one through sub-2 nm hotspots. As a stringent test, we investigated the discrimination of vasopressin and oxytocin, two peptides differing by only two amino acids. Using electrophoretic delivery and ultrafast SERS detection with a single-photon avalanche diode camera, we captured spectra on microsecond time scales. Machine-learning analysis achieved 70.5% classification accuracy at the single-peptide level, rising to 99% discrimination when averaging 40 events. These results establish flow-through nanopore SERS as a promising route toward single-molecule peptide identification in biomedical settings.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"15 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2026-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147492573","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 : 2026-03-18DOI: 10.1021/acsphotonics.5c02595
Ruizhao Yao, Danjun Liu, Tao Yan, Sheng Lan, Guang-Can Li
Light can drive charge transfer across metal nanogaps via quantum tunnelling processes, underpinning diverse molecular optoelectronic devices. However, such optical quantum tunnelling effects are usually significant at the subnanometer scale, which is not readily accessible. Here, we demonstrated that the threshold tunnelling gap distance, below which the quantum tunnelling effects become significant, strongly depends on the gap morphologies and can be significantly extended to >1.3 nm in planar plasmonic gaps. Furthermore, a phenomenological model was developed to illustrate how this threshold gap distance correlates with gap morphology. These findings provide new insights into quantum tunnelling effects in plasmonic nanogaps and point out how to relax the size requirement for accessing quantum tunnelling effects in plasmonic nanosystems, significant for quantum plasmonics and relevant applications.
{"title":"Extended Quantum Tunnelling Distance in Planar Plasmonic Gaps","authors":"Ruizhao Yao, Danjun Liu, Tao Yan, Sheng Lan, Guang-Can Li","doi":"10.1021/acsphotonics.5c02595","DOIUrl":"https://doi.org/10.1021/acsphotonics.5c02595","url":null,"abstract":"Light can drive charge transfer across metal nanogaps via quantum tunnelling processes, underpinning diverse molecular optoelectronic devices. However, such optical quantum tunnelling effects are usually significant at the subnanometer scale, which is not readily accessible. Here, we demonstrated that the threshold tunnelling gap distance, below which the quantum tunnelling effects become significant, strongly depends on the gap morphologies and can be significantly extended to >1.3 nm in planar plasmonic gaps. Furthermore, a phenomenological model was developed to illustrate how this threshold gap distance correlates with gap morphology. These findings provide new insights into quantum tunnelling effects in plasmonic nanogaps and point out how to relax the size requirement for accessing quantum tunnelling effects in plasmonic nanosystems, significant for quantum plasmonics and relevant applications.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"6 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2026-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147478427","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 : 2026-03-18DOI: 10.1021/acsphotonics.5c02559
Deng Liu, Rong Li, Shuhui Li, Jian Wang
Multimode fibers (MMFs) are attractive as ultraminiaturized probes for minimally invasive endoscopic imaging, yet their spatial resolution is intrinsically constrained by the fiber’s numerical aperture (NA). Here, we introduce a simple and effective strategy to enhance the NA of MMF imaging probes by integrating a high-refractive-index glass microsphere (GMS) at the fiber endface. The GMS matches the fiber’s diameter, preserving the probe’s compact dimensions, and its optical functionality derives primarily from spherical curvature combined with a sufficiently high refractive index, rather than from complex microfabrication. We measure the transmission matrix of the MMF–GMS probe, which captures the combined transmission properties of both the fiber and the microsphere. This enables the correction of distortions introduced by the entire probe, allowing precise control of the input optical fields to generate desired output optical fields at the probe endface. Using this approach, submicrometer focal spots (∼0.455 μm) are generated at the probe output, increasing the effective NA from ∼0.18 to ∼0.60 compared with a bare MMF. Furthermore, laser-scanning imaging at the distal end of the MMF–GMS probe reveals minimal aberrations and a more than 3-fold enhancement in spatial resolution. This low-cost, compact NA-enhanced MMF–GMS probe holds great promise for advancing high-resolution minimally invasive endoscopy and opening new opportunities for emerging high-precision optical applications.
{"title":"Multimode Fiber Imaging with High Numerical Aperture","authors":"Deng Liu, Rong Li, Shuhui Li, Jian Wang","doi":"10.1021/acsphotonics.5c02559","DOIUrl":"https://doi.org/10.1021/acsphotonics.5c02559","url":null,"abstract":"Multimode fibers (MMFs) are attractive as ultraminiaturized probes for minimally invasive endoscopic imaging, yet their spatial resolution is intrinsically constrained by the fiber’s numerical aperture (NA). Here, we introduce a simple and effective strategy to enhance the NA of MMF imaging probes by integrating a high-refractive-index glass microsphere (GMS) at the fiber endface. The GMS matches the fiber’s diameter, preserving the probe’s compact dimensions, and its optical functionality derives primarily from spherical curvature combined with a sufficiently high refractive index, rather than from complex microfabrication. We measure the transmission matrix of the MMF–GMS probe, which captures the combined transmission properties of both the fiber and the microsphere. This enables the correction of distortions introduced by the entire probe, allowing precise control of the input optical fields to generate desired output optical fields at the probe endface. Using this approach, submicrometer focal spots (∼0.455 μm) are generated at the probe output, increasing the effective NA from ∼0.18 to ∼0.60 compared with a bare MMF. Furthermore, laser-scanning imaging at the distal end of the MMF–GMS probe reveals minimal aberrations and a more than 3-fold enhancement in spatial resolution. This low-cost, compact NA-enhanced MMF–GMS probe holds great promise for advancing high-resolution minimally invasive endoscopy and opening new opportunities for emerging high-precision optical applications.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"11 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2026-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147492574","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}
Silicon-based microring modulators (MRMs) are emerging as essential components in wavelength-division multiplexing (WDM) systems due to their compact footprint, low power consumption, and inherent wavelength selectivity. However, conventional add-drop MRMs face challenges such as limited modulation efficiency and a trade-off between electro-optic (EO) bandwidth and efficiency. Here, we present a high-performance 4 × 400 Gbps WDM transmitter operating in both the O-band and C-band, fabricated on a 300 mm CMOS silicon photonics platform. By optimizing the doping profile across the microring, the bus waveguides, and the coupling sections, the MRMs achieve 3 dB EO bandwidths exceeding 67 GHz and modulation efficiencies as low as 0.57 V·cm for the O-band and 0.65 V·cm for the C-band. At 400 Gbps using PAM-6 modulation, the power consumption is reduced to ∼0.40 fJ/bit for both bands. The demonstrated four-channel transmitter achieves an aggregate data rate of 1.6 Tbps within a compact footprint of 1 × 0.27 mm2, corresponding to a data-rate density of approximately 5.9 Tbps/mm2. These results highlight the potential of our silicon photonic transmitter for high-capacity optical interconnects in data centers and AI-driven architectures.
{"title":"High-Density 4 × 400 Gbps WDM Transmitter with Energy-Efficient Silicon Microring Modulators in O- and C-Bands","authors":"Xin Wang, Fenghe Yang, Ruoyu Shen, Yaotian Zhao, Xu Wang, Fangchen Hu, Haiwen Cai, Wei Chu","doi":"10.1021/acsphotonics.6c00297","DOIUrl":"https://doi.org/10.1021/acsphotonics.6c00297","url":null,"abstract":"Silicon-based microring modulators (MRMs) are emerging as essential components in wavelength-division multiplexing (WDM) systems due to their compact footprint, low power consumption, and inherent wavelength selectivity. However, conventional add-drop MRMs face challenges such as limited modulation efficiency and a trade-off between electro-optic (EO) bandwidth and efficiency. Here, we present a high-performance 4 × 400 Gbps WDM transmitter operating in both the O-band and C-band, fabricated on a 300 mm CMOS silicon photonics platform. By optimizing the doping profile across the microring, the bus waveguides, and the coupling sections, the MRMs achieve 3 dB EO bandwidths exceeding 67 GHz and modulation efficiencies as low as 0.57 V·cm for the O-band and 0.65 V·cm for the C-band. At 400 Gbps using PAM-6 modulation, the power consumption is reduced to ∼0.40 fJ/bit for both bands. The demonstrated four-channel transmitter achieves an aggregate data rate of 1.6 Tbps within a compact footprint of 1 × 0.27 mm<sup>2</sup>, corresponding to a data-rate density of approximately 5.9 Tbps/mm<sup>2</sup>. These results highlight the potential of our silicon photonic transmitter for high-capacity optical interconnects in data centers and AI-driven architectures.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"17 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2026-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147470955","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}
Whispering gallery mode (WGM) microcavity magnetometers have emerged as a frontier in high-sensitivity magnetic field sensing, owing to their room-temperature operation capability, miniature footprint, and exceptional immunity to electromagnetic interference. In this work, we propose an innovative design of a fully encapsulated, probe-type WGM microcavity magnetometer with microsecond magnetic field response which overcomes application bottlenecks in complex environments. By precisely fabricating an epoxy-oxide microbottle cavity on the surface of a cylindrical magnetostrictive Terfenol-D substrate, we achieved a high-quality (Q) factor exceeding 106 with an outstanding detection sensitivity up to 25.2 nT/Hz1/2. The probe device can detect magnetic field frequencies from DC to 19 MHz, and in turn it can utilize magnetic fields to achieve a wide range (∼50 GHz) with fast scanning for the mode. We further report a magnetic field imaging technique, in which the probe serves as the sensing unit to accurately reconstruct the magnetic field distribution of the sample. This result highlights the broad application potential of our probe in magnetic field detection and imaging.
{"title":"High-Sensitive Magnetic Field Sensing and Imaging with Optical Microcavity Probe","authors":"Jialve Sun, Liaosha Kuang, Tinglan Chen, Zijin Cai, Jian-Fei Liu, Bei-Bei Li, Fangxing Zhang, Heng Zhou, Cheng Ma","doi":"10.1021/acsphotonics.5c02667","DOIUrl":"https://doi.org/10.1021/acsphotonics.5c02667","url":null,"abstract":"Whispering gallery mode (WGM) microcavity magnetometers have emerged as a frontier in high-sensitivity magnetic field sensing, owing to their room-temperature operation capability, miniature footprint, and exceptional immunity to electromagnetic interference. In this work, we propose an innovative design of a fully encapsulated, probe-type WGM microcavity magnetometer with microsecond magnetic field response which overcomes application bottlenecks in complex environments. By precisely fabricating an epoxy-oxide microbottle cavity on the surface of a cylindrical magnetostrictive Terfenol-D substrate, we achieved a high-quality (Q) factor exceeding 10<sup>6</sup> with an outstanding detection sensitivity up to 25.2 <i>n</i>T/Hz<sup>1/2</sup>. The probe device can detect magnetic field frequencies from DC to 19 MHz, and in turn it can utilize magnetic fields to achieve a wide range (∼50 GHz) with fast scanning for the mode. We further report a magnetic field imaging technique, in which the probe serves as the sensing unit to accurately reconstruct the magnetic field distribution of the sample. This result highlights the broad application potential of our probe in magnetic field detection and imaging.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"11 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147466058","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}
Topological insulators (TIs) exhibit insulating bulk and topologically protected metallic surface states, offering great potential for spintronics, quantum information, and ultrafast optoelectronic devices. Understanding how coherent phonon modes are generated and how their characteristics evolve with temperature in TI thin films is essential for clarifying their ultrafast dynamics. In this work, we employ a temperature-controlled transmission pump–probe system to investigate coherent phonon behavior in Bi2Te3 thin films. Multiple coherent phonon modes are resolved, including coherent acoustic oscillations and the Raman-active A1g1, A1g2, and Eg2 modes. The A1g1 mode exhibits strong temperature dependence, with its frequency red-shifting from 1.90 to 1.85 THz and its lifetime decreasing from 13 ps at 78 K to 4 ps at 290 K. The A1g2 mode shows shorter intrinsic coherence (2.6 → 1.2 ps) and stronger damping, while the weaker Eg2 mode is observed only at cryogenic temperatures. Coherent acoustic phonons (CAPs) display similar softening and damping trends. Taken together, these temperature-controlled transmission measurements show that temperature strongly influences phonon frequencies, lifetimes, and coherence in Bi2Te3 thin films, highlight differences between transmission- and reflection-based measurements, and may help guide the design of ultrafast TI-based optoelectronic and spintronic devices.
{"title":"Ultrafast Carrier–Phonon Coupling and Temperature-Dependent Coherent Phonon Dynamics in Bi2Te3 Thin Films","authors":"Xianting Zhang, Siyao Li, Hsuan-Yin Chen, Che-Wei Huang, Jung-Chun-Andrew Huang, Chao-Kuei Lee, Hsiang-Chen Chui","doi":"10.1021/acsphotonics.5c02213","DOIUrl":"https://doi.org/10.1021/acsphotonics.5c02213","url":null,"abstract":"Topological insulators (TIs) exhibit insulating bulk and topologically protected metallic surface states, offering great potential for spintronics, quantum information, and ultrafast optoelectronic devices. Understanding how coherent phonon modes are generated and how their characteristics evolve with temperature in TI thin films is essential for clarifying their ultrafast dynamics. In this work, we employ a temperature-controlled transmission pump–probe system to investigate coherent phonon behavior in Bi<sub>2</sub>Te<sub>3</sub> thin films. Multiple coherent phonon modes are resolved, including coherent acoustic oscillations and the Raman-active <i>A</i><sub>1<i>g</i></sub><sup>1</sup>, <i>A</i><sub>1<i>g</i></sub><sup>2</sup>, and <i>E</i><sub><i>g</i></sub><sup>2</sup> modes. The <i>A</i><sub>1<i>g</i></sub><sup>1</sup> mode exhibits strong temperature dependence, with its frequency red-shifting from 1.90 to 1.85 THz and its lifetime decreasing from 13 ps at 78 K to 4 ps at 290 K. The <i>A</i><sub>1<i>g</i></sub><sup>2</sup> mode shows shorter intrinsic coherence (2.6 → 1.2 ps) and stronger damping, while the weaker <i>E</i><sub><i>g</i></sub><sup>2</sup> mode is observed only at cryogenic temperatures. Coherent acoustic phonons (CAPs) display similar softening and damping trends. Taken together, these temperature-controlled transmission measurements show that temperature strongly influences phonon frequencies, lifetimes, and coherence in Bi<sub>2</sub>Te<sub>3</sub> thin films, highlight differences between transmission- and reflection-based measurements, and may help guide the design of ultrafast TI-based optoelectronic and spintronic devices.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"27 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147465975","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 : 2026-03-17DOI: 10.1021/acsphotonics.5c02597
Zhenyu Liu, Randy Te Morsche, Mingjian You, Ning Ding, Xingyu Tang, Weiren Cheng, David Marpaung, Qiancheng Zhao
Third-order nonlinear optical phenomena, particularly stimulated Brillouin scattering (SBS) and Kerr nonlinearity, lay the foundation for various advanced nonlinear applications. Integrating these effects within a low-loss, thermorefractive-stable, and CMOS-compatible photonic platform enables multifunctional and versatile nonlinear photonic integrated circuits. Here, we demonstrate the first backward SBS in tantalum pentoxide (Ta2O5) waveguides, revealing a Brillouin gain of m–1 W–1 at a Brillouin frequency shift of 11.23 GHz. The strong nonlinear refractive index of ×10–19 m2/W supports efficient supercontinuum generation (SCG) and four-wave mixing (FWM) in dispersion-engineered strip and rib waveguides across both anomalous and normal dispersion regimes. In the anomalous dispersion regime, SCG exceeding 300 nm is realized and theoretically extendable to over 1100 nm. FWM experiments exhibit a conversion efficiency of −48.1 dB and a potential bandwidth of 120 nm. In the normal dispersion regime, a flat supercontinuum spanning over 180 nm with power fluctuations below 15 dB is generated, serving as a broadband source for acetylene gas spectroscopy. Ta2O5 outperforms other platforms such as silicon, silicon nitride, and lithium niobate in terms of Kerr nonlinearity, SBS gain, and thermorefractive stability, with a figure of merit of 1.7 × 10–12 m·K·W–2, highlighting its exceptional versatility for multifunctional integrated nonlinear photonics.
{"title":"Tantalum Pentoxide Integrated Photonics II: A Promising Photonic Platform for Third-Order Nonlinearities","authors":"Zhenyu Liu, Randy Te Morsche, Mingjian You, Ning Ding, Xingyu Tang, Weiren Cheng, David Marpaung, Qiancheng Zhao","doi":"10.1021/acsphotonics.5c02597","DOIUrl":"https://doi.org/10.1021/acsphotonics.5c02597","url":null,"abstract":"Third-order nonlinear optical phenomena, particularly stimulated Brillouin scattering (SBS) and Kerr nonlinearity, lay the foundation for various advanced nonlinear applications. Integrating these effects within a low-loss, thermorefractive-stable, and CMOS-compatible photonic platform enables multifunctional and versatile nonlinear photonic integrated circuits. Here, we demonstrate the first backward SBS in tantalum pentoxide (Ta<sub>2</sub>O<sub>5</sub>) waveguides, revealing a Brillouin gain of <i></i><math display=\"inline\"><msubsup><mrow><mn>4.9</mn></mrow><mrow><mrow><mo>−</mo></mrow><mrow><mn>1.8</mn></mrow></mrow><mrow><mrow><mo>+</mo></mrow><mrow><mn>2.3</mn></mrow></mrow></msubsup></math> m<sup>–1</sup> W<sup>–1</sup> at a Brillouin frequency shift of 11.23 GHz. The strong nonlinear refractive index of <i></i><math display=\"inline\"><msubsup><mrow><mn>7.8</mn></mrow><mrow><mrow><mo>−</mo></mrow><mrow><mn>2.4</mn></mrow></mrow><mrow><mrow><mo>+</mo></mrow><mrow><mn>3.5</mn></mrow></mrow></msubsup></math>×10<sup>–19</sup> m<sup>2</sup>/W supports efficient supercontinuum generation (SCG) and four-wave mixing (FWM) in dispersion-engineered strip and rib waveguides across both anomalous and normal dispersion regimes. In the anomalous dispersion regime, SCG exceeding 300 nm is realized and theoretically extendable to over 1100 nm. FWM experiments exhibit a conversion efficiency of −48.1 dB and a potential bandwidth of 120 nm. In the normal dispersion regime, a flat supercontinuum spanning over 180 nm with power fluctuations below 15 dB is generated, serving as a broadband source for acetylene gas spectroscopy. Ta<sub>2</sub>O<sub>5</sub> outperforms other platforms such as silicon, silicon nitride, and lithium niobate in terms of Kerr nonlinearity, SBS gain, and thermorefractive stability, with a figure of merit of 1.7 × 10<sup>–12</sup> m·K·W<sup>–2</sup>, highlighting its exceptional versatility for multifunctional integrated nonlinear photonics.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"31 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147466057","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 : 2026-03-17DOI: 10.1021/acsphotonics.5c03041
Kanak Kanti Bhowmik, Xiaolei Zhao, Travis Wanless, Stephen H. Foulger, Lin Zhu, Hai Xiao, Lianfeng Zhao
The realization of electrically pumped perovskite lasers is currently hindered by a fundamental “cathode conflict”: noble metals like silver (Ag) are required for low optical modal loss but lack the proper work function for efficient electron injection, whereas the standard lithium fluoride/aluminum (LiF/Al) cathode ensures superior electron injection but introduces prohibitive optical absorption. Here, we present a device engineering strategy that decouples these constraints by utilizing the electron transport layer (ETL) as a geometric optical spacer. We demonstrate that increasing the ETL thickness from 40 to 200 nm effectively isolates the optical mode from the cathode interface, suppressing modal absorption. This optimization enables a perovskite LED with a standard, optically lossy LiF/Al cathode to achieve amplified spontaneous emission (ASE) under optical pumping, a milestone typically restricted to noble metal electrodes. Furthermore, under nanosecond pulsed electrical operation, the 200 nm ETL device exhibits superior electroluminescence intensity compared to conventional thin-ETL structures, attributed to enhanced charge balance and hole-blocking capabilities. This work establishes a viable pathway to integrate electrically efficient LiF/Al cathodes into low-loss optical cavities, addressing a critical trade-off toward the realization of perovskite laser diodes.
{"title":"Thick Charge Transport Layers Enable Amplified Spontaneous Emission and Enhanced Electroluminescence in Lossy Aluminum-Cathode Perovskite LEDs","authors":"Kanak Kanti Bhowmik, Xiaolei Zhao, Travis Wanless, Stephen H. Foulger, Lin Zhu, Hai Xiao, Lianfeng Zhao","doi":"10.1021/acsphotonics.5c03041","DOIUrl":"https://doi.org/10.1021/acsphotonics.5c03041","url":null,"abstract":"The realization of electrically pumped perovskite lasers is currently hindered by a fundamental “cathode conflict”: noble metals like silver (Ag) are required for low optical modal loss but lack the proper work function for efficient electron injection, whereas the standard lithium fluoride/aluminum (LiF/Al) cathode ensures superior electron injection but introduces prohibitive optical absorption. Here, we present a device engineering strategy that decouples these constraints by utilizing the electron transport layer (ETL) as a geometric optical spacer. We demonstrate that increasing the ETL thickness from 40 to 200 nm effectively isolates the optical mode from the cathode interface, suppressing modal absorption. This optimization enables a perovskite LED with a standard, optically lossy LiF/Al cathode to achieve amplified spontaneous emission (ASE) under optical pumping, a milestone typically restricted to noble metal electrodes. Furthermore, under nanosecond pulsed electrical operation, the 200 nm ETL device exhibits superior electroluminescence intensity compared to conventional thin-ETL structures, attributed to enhanced charge balance and hole-blocking capabilities. This work establishes a viable pathway to integrate electrically efficient LiF/Al cathodes into low-loss optical cavities, addressing a critical trade-off toward the realization of perovskite laser diodes.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"57 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147470957","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}
Reconfigurable metasurfaces offer a promising route toward compact optical systems, yet many dynamic schemes rely on spectral tuning to realize reconfiguration, which limits programmable task-level switching at a fixed operating wavelength. Here we demonstrate a nonvolatile, switchable wavefront module operating at a fixed wavelength (λ = 780 nm) using an Sb2S3 phase-change metasurface. The optical transfer function is deterministically rewritten through the material phase transition, enabling two distinct processing operators within the same aperture via phase-state-controlled polarization-basis switching. In the amorphous state, the device operates in the circular-polarization basis as a beam-control module, providing RCP-addressed on-axis focusing at z = 51 μm (fwhm = 2.26 μm) and LCP-addressed off-axis beam steering with a deflection angle of 25.7°. After crystallization, it operates in the linear-polarization basis as a holographic reconstructor, enabling independent image reconstruction under x- and y-polarized illumination. Clear phase-state- and polarization-addressed channel selectivity is observed, and nonvolatile write–erase operation is demonstrated over 10 cycles while preserving the designed outputs across all four channels. This compact module supports holographic display and optical security in one state and beam pointing, scanning, and coupling enhancement in the other, providing a practical platform for integrated reconfigurable optics with deterministic on-demand function switching.
{"title":"Fixed-Wavelength Cross-Modal Wavefront Reconfiguration via Phase-State Control in Sb2S3 Metasurfaces","authors":"Wenbin Wang, Nan Yang, Shuhao Si, Liangcai Wu, Yangjian Cai, Yun Meng","doi":"10.1021/acsphotonics.6c00130","DOIUrl":"https://doi.org/10.1021/acsphotonics.6c00130","url":null,"abstract":"Reconfigurable metasurfaces offer a promising route toward compact optical systems, yet many dynamic schemes rely on spectral tuning to realize reconfiguration, which limits programmable task-level switching at a fixed operating wavelength. Here we demonstrate a nonvolatile, switchable wavefront module operating at a fixed wavelength (λ = 780 nm) using an Sb<sub>2</sub>S<sub>3</sub> phase-change metasurface. The optical transfer function is deterministically rewritten through the material phase transition, enabling two distinct processing operators within the same aperture via phase-state-controlled polarization-basis switching. In the amorphous state, the device operates in the circular-polarization basis as a beam-control module, providing RCP-addressed on-axis focusing at z = 51 μm (fwhm = 2.26 μm) and LCP-addressed off-axis beam steering with a deflection angle of 25.7°. After crystallization, it operates in the linear-polarization basis as a holographic reconstructor, enabling independent image reconstruction under x- and y-polarized illumination. Clear phase-state- and polarization-addressed channel selectivity is observed, and nonvolatile write–erase operation is demonstrated over 10 cycles while preserving the designed outputs across all four channels. This compact module supports holographic display and optical security in one state and beam pointing, scanning, and coupling enhancement in the other, providing a practical platform for integrated reconfigurable optics with deterministic on-demand function switching.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"33 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147466059","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}
Wavelength division multiplexing (WDM) optical interconnect technology offers an effective solution for addressing the ever-increasing data traffic. Microring modulators (MRMs), owing to their high bandwidth, compact footprint, and inherent wavelength selectivity, have become key building blocks in WDM systems. However, the limited free spectral range (FSR) of MRMs restricts the number of available wavelength channels and the corresponding overall data rate capacity in WDM systems. In this study, we propose an optimized Bezier-bent MRM, in which the device radius is reduced to 3 μm to significantly enhance the FSR. The proposed MRM operates without the need for a DC bias voltage and an RF amplifier, exhibiting a low insertion loss of 0.4 dB, an ultrawide FSR exceeding 4 THz, and a high electro-optic bandwidth of over 110 GHz. Back-to-back (BtB) transmission experiments demonstrate that the modulator supports 400 Gbps PAM-8 data transmission under a driving voltage of only 1 V, satisfying the 7% hard-decision forward error correction (HD-FEC) bit-error-rate (BER) threshold of 3.8 × 10–3. Owing to the compact-radius design, the junction capacitance is substantially reduced, enabling an exceptionally low modulation power consumption of 0.2 fJ/bit. The proposed MRM presents significant potential for dense integration in future optical communication systems.
{"title":"A 400 Gbps Microring Modulator with 4.2 THz FSR Using Optimized Bezier Bend in a 300 mm CMOS Platform","authors":"Xin Wang, Fenghe Yang, Xu Wang, Ruoyu Shen, Yue Zhou, Erse Jia, Aoxue Wang, Fangchen Hu, Haiwen Cai, Wei Chu","doi":"10.1021/acsphotonics.5c02442","DOIUrl":"https://doi.org/10.1021/acsphotonics.5c02442","url":null,"abstract":"Wavelength division multiplexing (WDM) optical interconnect technology offers an effective solution for addressing the ever-increasing data traffic. Microring modulators (MRMs), owing to their high bandwidth, compact footprint, and inherent wavelength selectivity, have become key building blocks in WDM systems. However, the limited free spectral range (FSR) of MRMs restricts the number of available wavelength channels and the corresponding overall data rate capacity in WDM systems. In this study, we propose an optimized Bezier-bent MRM, in which the device radius is reduced to 3 μm to significantly enhance the FSR. The proposed MRM operates without the need for a DC bias voltage and an RF amplifier, exhibiting a low insertion loss of 0.4 dB, an ultrawide FSR exceeding 4 THz, and a high electro-optic bandwidth of over 110 GHz. Back-to-back (BtB) transmission experiments demonstrate that the modulator supports 400 Gbps PAM-8 data transmission under a driving voltage of only 1 V, satisfying the 7% hard-decision forward error correction (HD-FEC) bit-error-rate (BER) threshold of 3.8 × 10<sup>–3</sup>. Owing to the compact-radius design, the junction capacitance is substantially reduced, enabling an exceptionally low modulation power consumption of 0.2 fJ/bit. The proposed MRM presents significant potential for dense integration in future optical communication systems.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":"44 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2026-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147470954","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：