Electrical and Electronic Engineering, Electronic, Optical and Magnetic Materials
54
Scopus Publications
Scopus Publications
1-MHz linewidth VCSEL enabled by monolithically integrated passive cavity for high-stability chip-scale atomic clocks Zhiting Tang, Chuanlin Li, Xuhao Zhang, Wuyang Ren, Kai Shen, Chuang Li, Qingsong Bai, Jin Li, Aobo Ren, Hao Wang, Xiaorong Luo, Hongxing Xu, Jiang Wu Light Science and Applications, 2026 Narrow-linewidth vertical-cavity surface-emitting lasers (VCSELs) are key enablers for chip-scale atomic clocks and quantum sensors, yet conventional designs suffer from short cavity lengths and excess spontaneous emission, resulting in broad linewidths and degraded frequency stability. Here, we demonstrate a monolithically integrated VCSEL operating at the cesium D 1 line (894.6 nm) that achieves intrinsic linewidth compression to ~1 MHz, without requiring external optical feedback. This performance is enabled by embedding a passive cavity adjacent to the active region, which spatially redistributes the optical field into a low-loss region, extending photon lifetime while suppressing higher-order transverse and longitudinal modes. The resulting device exhibits robust single-mode operation over a wide current and temperature range, with side-mode suppression ratio (SMSR) > 35 dB, orthogonal polarization suppression ratio (OPSR) > 25 dB and a beam divergence of ~7°. Integrated into a Cesium vapor-cell atomic clock, the VCSEL supports a frequency stability of 1.89 × 10 –12 τ -1/2 . These results position this VCSEL architecture as a compact, scalable solution for next-generation quantum-enabled frequency references and sensing platforms.
Sub-picojoule-per-bit volitional neuromorphic devices for precise targeting and tracking Yixuan Huang, Qihao Sun, Fuxing Dai, Fang Wang, Xiangyu Zhou, Chenyu Huang, Yanlin Wu, Yizhe Deng, Li Luo, Xiao Li, Chuang Li, Wuyang Ren, Aobo Ren, Xiao Fu, Kai Shen, Weida Hu, Jiang Wu Nature Communications, 2026 The technological revolution driven by artificial intelligence has significantly improved the hardware performance, but energy consumption remains a critical bottleneck. The state-of-the-art retinomorphic devices, as core components of artificial intelligence hardware, excel in feature extraction but are constrained by passive attention mechanisms that lack flexibility of actively extracting additional features. Inspired by the human visual system, this work introduces a volitional neuromorphic device with active volitional attention regulation. By leveraging gate-voltage-tunable photoconductance to generate adjustable differential spectral response and employing neural networks to evaluate spectral reconstruction accuracy, the device achieves selective task perception. Experimental results demonstrate a data compression ratio of 1.17% and an extreme information energy efficiency of 0.625 pJ/bit. This advancement not only advances retinomorphic hardware design but also provides a sustainable pathway for energy-efficient hyperspectral imaging and next-generation neuromorphic computing systems. Energy consumption is a challenge in AI hardware. The authors introduce a volitional neuromorphic device that mimics human visual attention, achieving high energy efficiency and precise object tracking with minimal data redundancy.
Phase fields in momentum space of photonic crystal slabs Chuanlin LI, Aobo REN, Jiang WU Wuli Xuebao Acta Physica Sinica, 2026 光学相位调控在光通信、信息处理和精密测量等领域具有重要意义。相较于实空间调控,动量空间相位调控展现出显著优势:无结构中心束缚、模式容量不受限,且具备本征的拓扑保护特性。这种内在的灵活性与可扩展性,使得系统在实际应用中无需严格的光学对准,并能提供大量独立的调控通道,推动高性能、高集成度光学系统的发展。光子晶体板以其开放边界周期性以及动量空间光场操控等优势,已成为动量空间相位场研究的重要平台。本文基于偏振正交分解和时域耦合模式理论下的散射矩阵,系统阐述了光子晶体板中二维动量空间和多维合成动量空间相位场的产生机理,并综述了近几年来的相关研究与应用进展。最后,对动量空间相位场领域的发展现状、核心优势与挑战进行了总结和展望。
High-Fidelity and Low-Latency Machine Vision via Manipulation of Contact Potential Behaviors at Perovskite Hetero-Interfaces Xiangyu Zhou, Kai Shen, Yixuan Huang, Feiyun Zhao, Qihao Sun, Yufan Deng, Wenwu Wang, Fan Cui, Chuang Li, Wuyang Ren, Daqian Guo, Yimu Chen, Aobo Ren, Jiang Wu Advanced Materials, 2026 Artificial intelligence (AI)‐driven machine vision is reshaping the industrial perception paradigm, highlighting the critical demands of high‐performance vision hardware. Among various emerging vision techniques, perovskite photodetectors have demonstrated exceptional promise but faced a long‐term trade‐off between external quantum efficiency (EQE) and response time, posing a significant challenge for high‐fidelity and low‐latency vision applications. Here, the transport‐limited mechanism is confirmed to fundamentally dominates response time, and high‐bandwidth and high‐sensitivity perovskite photodiodes are demonstrated by manipulating contact potential behaviors through polymer‐polarized passive dipoles. Specifically, the synergistic incorporation of dipole‐rich molecular modifiers with polar functional groups and electronegative atoms effectively rearranges charge distribution, leading to an increased potential difference and homogeneous potential profiles at perovskite hetero‐interfaces. Accordingly, reduced conduction and valence band offsets facilitate carrier transport and suppress non‐radiative recombination. The device simultaneously delivers an impressive bandwidth of 25.7 MHz and a high EQE exceeding 88%, enabling a high‐fidelity and low‐latency imaging of fast rotating motion (≈18 750 rpm) with negligible ghosting. This work provides an effective strategy to approach the transport limit of vision hardware, laying a solid foundation for next‐generation AI scenarios.
Ytterbium dopant-manipulated neuromorphic behavior for wavelength-dependent dual-modal photodetection Sadeq Abbasi, Xiangyu Zhou, Lechuan Chen, Aobo Ren, Fan Cui, Kai Shen Applied Physics Letters, 2025 Integrating sensing and neuromorphic functions within a single low-power platform remains a key challenge in optoelectronic device design. We report a dual-modal perovskite photodetector by incorporating YbCl3 as a dopant, which simultaneously achieves neuromorphic behavior and conventional optoelectronic properties. Systematic characterizations of doping manipulation reveal that 0.5% YbCl3 can optimally modulate film crystallinity, enhance carrier transport, and tune charge dynamics. Notably, the 0.5% doped device exhibited distinct wavelength-dependent photoresponse, and hallmarks of depression-like neuromorphic behavior are were observed under pulsed 905 nm light excitation. This behavior is clearly supported by negative photoconductivity, gradual baseline modulation, and a prolonged post-illumination tail. However, these adaptive current dynamics are absent under 635 nm light illumination; the device instead demonstrated enhanced photoresponse, with responsivity increasing from 0.45 to 0.73 A/W and detectivity from 1.4 × 1012 to 5.1 × 1012 Jones. This spectral contrast originates from the wavelength-dependent activation of Yb3+-related trap states, confirmed by photoluminance measurements. These findings position YbCl3 doping as a versatile strategy for advancing perovskite photodetectors toward dual-modal photodetection, with ongoing studies exploring broader applicability.
End-to-end all-optical nonlinear activator enabled by a Brillouin fiber amplifier Caihong Teng, Qihao Sun, Shengkun Chen, Yixuan Huang, Lingjie Zhang, Aobo Ren, Jiang Wu Photonics Research, 2025 The rapid growth of deep learning applications has sparked a revolution in computing paradigms, with optical neural networks (ONNs) emerging as a promising platform for achieving ultra-high computing power and energy efficiency. Despite great progress in analog optical computing, the lack of scalable optical nonlinearities and losses in photonic devices pose considerable challenges for power levels, energy efficiency, and signal latency. Here, we report an end-to-end all-optical nonlinear activator that utilizes the energy conversion of Brillouin scattering to perform efficient nonlinear processing. The activator exhibits an ultra-low activation threshold (24 nW), a wide transmission bandwidth (over 40 GHz), strong robustness, and high energy transfer efficiency. These advantages provide a feasible solution to overcome the existing bottlenecks in ONNs. As a proof-of-concept, a series of tasks is designed to validate the capability of the proposed activator as an activation unit for ONNs. Simulations show that the experiment-based nonlinear model outperforms classical activation functions in classification (97.64% accuracy for MNIST and 87.84% for Fashion-MNIST) and regression (with a symbol error rate as low as 0%) tasks. This work provides valuable insights into the innovative design of all-optical neural networks.
Reconfigurable hardware-accelerated, multi-channel, adaptive temperature control platform of VCSELs for high-density fNIRS/DOT Qiao He, Yunjia Xia, Xuhao Zhang, Xinkai Zhou, Yu Liu, Yixuan Huang, Xiangyu Zhou, Aobo Ren, Hubin Zhao, Jiang Wu Biomedical Optics Express, 2025 Functional near-infrared spectroscopy (fNIRS) and its advanced offshoot - diffuse optical tomography (DOT) are promising non-invasive neuroimaging techniques. The advancement of next-generation high-density fNIRS/DOT systems, particularly high-density wearable systems, requires compact light source arrays with high wavelength tuning precision and fine modulation capabilities. Vertical-cavity surface-emitting lasers (VCSELs) have emerged as a strong candidate for this purpose. However, VCSELs’ performance is highly sensitive to temperature variations, where heating effects induce wavelength shifts and output power fluctuations, leading to measurement drift and reduced accuracy in fNIRS/DOT data. Conventional multi-channel VCSEL temperature control methods face constraints due to limited computational resources and poor scalability. To address these limitations, we propose a reconfigurable hardware-accelerated temperature control platform based on the heterogeneous ZYNQ-7000 Field-programmable Gate Array (FPGA). By integrating a real-time proportional-integral-derivative (PID) algorithm into the programmable logic (PL), the platform achieves precise temperature regulation with an error margin of ±0.01 °C. Experimental validation demonstrates the encouraging capability of this proposed platform to regulate the temperature of over 100 VCSELs simultaneously while maintaining low resource utilization, ensuring efficient parallel control with large channel counts in real-time. The proposed reconfigurable architecture significantly enhances the reliability and scalability of VCSEL-driven fNIRS/DOT systems while maintaining sufficient resources for future implementations of extra functions. This platform not only improves the thermal stability of VCSELs-based wearable high-density fNIRS/DOT devices but also establishes a robust thermal-control framework for broader applications requiring high-density, thermally stable light source configurations.
Strain relaxation in halide perovskites via 2D/3D perovskite heterojunction formation Dongtao Liu, Jinxin Bi, Weidong Xu, Kieran W. P. Orr, Fei Wang, Xueping Liu, Aobo Ren, Jing Zhang, Steven Hinder, Bowei Li, Xiaoguang Luo, Yonglong Shen, Hanlin Hu, Guosheng Shao, Samuel D. Stranks, Lei Su, Wei Zhang Science Advances, 2025 Applying mechanical strain and strain engineering to halide perovskites has endowed them with intriguing properties. However, an in-depth understanding of mechanical strain, including residual strain in halide perovskites, remains incomplete, coupled with the critical challenge of decoupling strain effects from other interferences. Here, we examine the relaxation of residual tensile strain in three-dimensional (3D) halide perovskites through 2D/3D perovskite heterojunction formation. The 2D perovskite induces structural fragmentation in 3D perovskites, facilitating plastic relaxation of tensile strain. By isolating extrinsic crystalline phase interference and exciton-related optical disturbances, we observe that 3D perovskites retain high crystallinity only with moderate tensile strain relaxation. This moderate relaxation enhances optoelectronic properties in 3D perovskites, including broadened band-to-band absorption and prolonged charge carrier lifetime, markedly contributing to an increase in the maximum attainable power conversion efficiency in photovoltaic devices. Our findings outline conditions for strain relaxation that optimize optoelectronic properties, advancing strain engineering in halide perovskites.
High-Q unidirectional polarization singularities Chuanlin Li, Wenhao Wang, Jianfeng Chen, Mengqi Liu, Aobo Ren, Cheng-Wei Qiu, Hongxing Xu, Zhiming Wang, Jiang Wu Physical Review Applied, 2025 Unidirectional guided resonances (UGRs), which are eigenstates that radiate exclusively in a single channel, are promising for advancing diverse photonic devices. However, existing approaches face an inherent trade-off between achieving high-Q factors and maximizing the radiation-asymmetry ratios. To address this challenge, we propose a scheme that exploits both out-of-plane and in-plane couplings to generate bound states in the continuum with precise radial and rotational control in momentum space. This approach effectively decouples the Q factors of UGRs from their radiation-asymmetry ratios. As a result, we achieve UGRs with Q factors exceeding ${10}^{4}$, which is 1--2 orders of magnitude higher than traditional UGRs. Furthermore, we demonstrate the ability to reverse the emission direction of these UGRs, leading to a broad range of radiation-asymmetry ratios from \ensuremath{-}53 to 55 dB. We further validate the practical realization of high-Q UGRs using a silicon-on-silica system. Our findings provide a versatile method for generating high-Q UGRs, offering alternative pathways for innovations in nonlinear optics, light-matter interactions, and advanced optoelectronic applications.
Direct linearly polarized electroluminescence from perovskite nanoplatelet superlattices Junzhi Ye, Aobo Ren, Linjie Dai, Tomi K. Baikie, Renjun Guo, Debapriya Pal, Sebastian Gorgon, Julian E. Heger, Junyang Huang, Yuqi Sun, Rakesh Arul, Gianluca Grimaldi, Kaiwen Zhang, Javad Shamsi, Yi-Teng Huang, Hao Wang, Jiang Wu, A. Femius Koenderink, Laura Torrente Murciano, Matthias Schwartzkopf, Stephen V. Roth, Peter Müller-Buschbaum, Jeremy J. Baumberg, Samuel D. Stranks, Neil C. Greenham, Lakshminarayana Polavarapu, Wei Zhang, Akshay Rao, Robert L. Z. Hoye Nature Photonics, 2024
High-bandwidth perovskite photonic sources on silicon Aobo Ren, Hao Wang, Linjie Dai, Junfei Xia, Xinyu Bai, Edward Butler-Caddle, Joel A. Smith, Huagui Lai, Junzhi Ye, Xiang Li, Shijie Zhan, Chunhui Yao, Zewei Li, Mingchu Tang, Xueping Liu, Jinxin Bi, Bowei Li, Shen Kai, Rui Chen, Han Yan, Jintao Hong, Liming Yuan, Igor P. Marko, Adrian Wonfor, Fan Fu, Steven A. Hindmarsh, Ana M. Sanchez, James Lloyd-Hughes, Stephen J. Sweeney, Akshay Rao, Neil C. Greenham, Jiang Wu, Yanrong Li, Qixiang Cheng, Richard H. Friend, Richard V. Penty, Ian H. White, Henry J. Snaith, Wei Zhang Nature Photonics, 2023
Suppressing Interfacial Recombination with a Strong-Interaction Surface Modulator for Efficient Inverted Perovskite Solar Cells Bowei Li, Jun Deng, Joel A. Smith, Pietro Caprioglio, Kangyu Ji, Deying Luo, James D. McGettrick, K. D. G. Imalka Jayawardena, Rachel C. Kilbride, Aobo Ren, Steven Hinder, Jinxin Bi, Thomas Webb, Igor Marko, Xueping Liu, Yuren Xiang, Josh Reding, Hui Li, Shixuan Du, David G. Lidzey, Samuel D. Stranks, Trystan Watson, Stephen Sweeney, Henry J. Snaith, S. Ravi P. Silva, Wei Zhang Advanced Energy Materials, 2022