Pub Date : 2024-10-19DOI: 10.1021/acsphotonics.4c01467
Seok Joo Yang, Dharini Varadharajan, Kagachi Tateno, Yu-Ting Yang, Jeong Hui Kim, Kevin R. Pedersen, Sung-Doo Baek, Hanjun Yang, Aidan H. Coffey, Kenneth R. Graham, Bryan W. Boudouris, Letian Dou
In recent years, perovskite light-emitting diodes (PeLEDs) have demonstrated exceptional potential, achieving high external quantum efficiencies (EQEs) exceeding 20%. However, these advancements have primarily focused on visible colors, and toxic elements such as Pb are used in these devices. Tin (Sn) perovskites with a narrow band gap of nearly 1.3 eV present a promising candidate for lead-free near-infrared PeLEDs. Nonetheless, Sn oxidation and high defect density from fast crystallization are still hurdles to overcome. This study investigates the impact of a newly synthesized ethylenedioxythiophene (EDOT)-based conjugated organic ligand on Sn-based PeLEDs, aiming to enhance device performance by reducing the defect density and Sn oxidation. The EDOT-treated PeLED device achieves a high EQE of 6.4% and exhibits stable electroluminescence spectra, demonstrating the potential of ligand treatments in optimizing Sn-based PeLEDs.
{"title":"Interfacial Molecular Engineering for Efficient Sn Perovskite Light-Emitting Diodes","authors":"Seok Joo Yang, Dharini Varadharajan, Kagachi Tateno, Yu-Ting Yang, Jeong Hui Kim, Kevin R. Pedersen, Sung-Doo Baek, Hanjun Yang, Aidan H. Coffey, Kenneth R. Graham, Bryan W. Boudouris, Letian Dou","doi":"10.1021/acsphotonics.4c01467","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c01467","url":null,"abstract":"In recent years, perovskite light-emitting diodes (PeLEDs) have demonstrated exceptional potential, achieving high external quantum efficiencies (EQEs) exceeding 20%. However, these advancements have primarily focused on visible colors, and toxic elements such as Pb are used in these devices. Tin (Sn) perovskites with a narrow band gap of nearly 1.3 eV present a promising candidate for lead-free near-infrared PeLEDs. Nonetheless, Sn oxidation and high defect density from fast crystallization are still hurdles to overcome. This study investigates the impact of a newly synthesized ethylenedioxythiophene (EDOT)-based conjugated organic ligand on Sn-based PeLEDs, aiming to enhance device performance by reducing the defect density and Sn oxidation. The EDOT-treated PeLED device achieves a high EQE of 6.4% and exhibits stable electroluminescence spectra, demonstrating the potential of ligand treatments in optimizing Sn-based PeLEDs.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":null,"pages":null},"PeriodicalIF":7.0,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142449698","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 : 2024-10-18DOI: 10.1021/acsphotonics.4c00873
Chuang Zhang, Paul Bailey, Shuchun Zhang, Uyen Huynh, Xiaomei Jiang, Stephen McGill, Dmitry Semenov, Z. Valy Vardeny
We have studied the spin properties of localized photocarriers in the band tails (BT) of polycrystalline MAPbBr3 films having a nanometer crystal size using circularly polarized photoluminescence (PL) induced by a magnetic field up to 17.5 T at cryogenic temperatures as well as time-of-flight (TOF) transient photocurrent. The absorption spectrum of these films reveals BT states caused by structural and energetic disorders, having a broadly distributed Urbach edge ranging from 28 to 120 meV. This is corroborated by dispersive transport of photogenerated electrons and holes observed via TOF, where the photocarriers thermalize with time deeply in the BT, giving rise to time-dependent mobility. Consequently, the PL emission spectrum in these films originates from radiative recombination of the localized electron and hole pairs in the BT states. Upon applying a magnetic field in the Faraday configuration, field-induced circular polarized PL has been observed, from which an effective Landé g-factor of the localized e–h pairs, ge–h, was extracted to be 2.5 ± 0.2, in good agreement with the g-factor of free excitons measured using magnetic circular dichroism spectroscopy. In addition, we also found that the spin relaxation time for the e–h pairs in the BT states is ∼26 ns at 5 K and ∼10 ns at 80 K, indicating that nanocrystalline MAPbBr3 could be a good candidate for applications in spintronics and quantum computing.
我们利用在低温条件下由高达 17.5 T 的磁场诱导的圆偏振光发光（PL）以及飞行时间（TOF）瞬态光电流，研究了具有纳米晶体尺寸的多晶 MAPbBr3 薄膜带尾（BT）中局部光载流子的自旋特性。这些薄膜的吸收光谱显示了由结构和能量失调引起的 BT 状态，具有广泛分布的乌巴赫边缘，范围在 28 到 120 meV 之间。通过 TOF 观察到的光生电子和空穴的色散传输证实了这一点，光载流子随着时间的推移在 BT 的深处热化，从而产生了随时间变化的迁移率。因此，这些薄膜中的 PL 发射光谱源于 BT 态局部电子和空穴对的辐射重组。在法拉第构型中施加磁场后，观察到了场致圆极化聚光，从中提取出局域化电子-空穴对的有效朗德 g 因子 ge-h 为 2.5 ± 0.2，与利用磁性圆二色光谱测量的自由激子 g 因子非常吻合。此外，我们还发现 BT 态 e-h 对的自旋弛豫时间在 5 K 时为 ∼26 ns，在 80 K 时为 ∼10 ns，这表明纳米晶 MAPbBr3 是自旋电子学和量子计算应用的良好候选材料。
{"title":"Thermalization and Spin Relaxation Dynamics of Localized Photocarriers in the Band Tails of Nanocrystalline MAPbBr3 Films","authors":"Chuang Zhang, Paul Bailey, Shuchun Zhang, Uyen Huynh, Xiaomei Jiang, Stephen McGill, Dmitry Semenov, Z. Valy Vardeny","doi":"10.1021/acsphotonics.4c00873","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c00873","url":null,"abstract":"We have studied the spin properties of localized photocarriers in the band tails (BT) of polycrystalline MAPbBr<sub>3</sub> films having a nanometer crystal size using circularly polarized photoluminescence (PL) induced by a magnetic field up to 17.5 T at cryogenic temperatures as well as time-of-flight (TOF) transient photocurrent. The absorption spectrum of these films reveals BT states caused by structural and energetic disorders, having a broadly distributed Urbach edge ranging from 28 to 120 meV. This is corroborated by dispersive transport of photogenerated electrons and holes observed via TOF, where the photocarriers thermalize with time deeply in the BT, giving rise to time-dependent mobility. Consequently, the PL emission spectrum in these films originates from radiative recombination of the localized electron and hole pairs in the BT states. Upon applying a magnetic field in the Faraday configuration, field-induced circular polarized PL has been observed, from which an effective Landé <i>g</i>-factor of the localized e–h pairs, g<sub>e–h</sub>, was extracted to be 2.5 ± 0.2, in good agreement with the <i>g</i>-factor of free excitons measured using magnetic circular dichroism spectroscopy. In addition, we also found that the spin relaxation time for the e–h pairs in the BT states is ∼26 ns at 5 K and ∼10 ns at 80 K, indicating that nanocrystalline MAPbBr<sub>3</sub> could be a good candidate for applications in spintronics and quantum computing.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":null,"pages":null},"PeriodicalIF":7.0,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142448741","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 : 2024-10-18DOI: 10.1021/acsphotonics.4c00478
Andreas Geilen, Steven Becker, Birgit Stiller
In recent years, remarkable advances in photonic computing have highlighted the need for photonic memory, particularly high-speed and coherent random-access memory. Addressing the ongoing challenge of implementing photonic memories is required to fully harness the potential of photonic computing. A photonic-phononic memory based on stimulated Brillouin scattering is a possible solution, as it coherently transfers optical information into sound waves at high-speed. Such an optoacoustic memory has shown great potential as it fulfills key requirements for high-performance optical random-access memory due to its coherence, on-chip compatibility, frequency selectivity, and high bandwidth. However, the storage time has so far been limited to a few nanoseconds due to the nanosecond decay of the acoustic wave. In this work, we experimentally enhance the intrinsic storage time of an optoacoustic memory by more than 1 order of magnitude and coherently retrieve optical information after a storage time of 123 ns. This is achieved by employing the optoacoustic memory in a highly nonlinear fiber at 4.2 K, increasing the intrinsic phonon lifetime by a factor of 6. We demonstrate the capability of our scheme by measuring the initial and readout optical data pulses with a direct and double homodyne detection scheme. Finally, we analyze the dynamics of the optoacoustic memory at different cryogenic temperatures in the range of 4.2–20 K and compare the findings to continuous wave measurements. The extended storage time is beneficial not only for photonic computing but also for Brillouin applications that require long phonon lifetimes, such as optoacoustic filters, true-time delay networks, and synthesizers in microwave photonics.
近年来，光子计算的显著进步凸显了对光子存储器的需求，尤其是对高速和相干随机存取存储器的需求。要充分利用光子计算的潜力，就必须解决实施光子存储器的持续挑战。基于受激布里渊散射的光子-声子存储器是一种可能的解决方案，因为它能将光信息高速相干地传输到声波中。这种光声存储器因其相干性、片上兼容性、频率选择性和高带宽而满足了高性能光随机存取存储器的关键要求，因而显示出巨大的潜力。然而，由于声波的纳秒级衰减，存储时间迄今为止仅限于几纳秒。在这项工作中，我们通过实验将光声存储器的固有存储时间提高了 1 个数量级以上，并在 123 纳秒的存储时间后实现了光信息的相干检索。通过在 4.2 K 的高非线性光纤中使用光声存储器，将本征声子寿命提高了 6 倍，我们利用直接和双重同调检测方案测量了初始和读出光数据脉冲，证明了我们方案的能力。最后，我们分析了光声存储器在 4.2-20 K 范围内不同低温下的动态，并将结果与连续波测量结果进行了比较。延长存储时间不仅有利于光子计算，也有利于需要长声子寿命的布里渊应用，例如微波光子学中的光声滤波器、实时延迟网络和合成器。
{"title":"High-Speed Coherent Photonic Random-Access Memory in Long-Lasting Sound Waves","authors":"Andreas Geilen, Steven Becker, Birgit Stiller","doi":"10.1021/acsphotonics.4c00478","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c00478","url":null,"abstract":"In recent years, remarkable advances in photonic computing have highlighted the need for photonic memory, particularly high-speed and coherent random-access memory. Addressing the ongoing challenge of implementing photonic memories is required to fully harness the potential of photonic computing. A photonic-phononic memory based on stimulated Brillouin scattering is a possible solution, as it coherently transfers optical information into sound waves at high-speed. Such an optoacoustic memory has shown great potential as it fulfills key requirements for high-performance optical random-access memory due to its coherence, on-chip compatibility, frequency selectivity, and high bandwidth. However, the storage time has so far been limited to a few nanoseconds due to the nanosecond decay of the acoustic wave. In this work, we experimentally enhance the intrinsic storage time of an optoacoustic memory by more than 1 order of magnitude and coherently retrieve optical information after a storage time of 123 ns. This is achieved by employing the optoacoustic memory in a highly nonlinear fiber at 4.2 K, increasing the intrinsic phonon lifetime by a factor of 6. We demonstrate the capability of our scheme by measuring the initial and readout optical data pulses with a direct and double homodyne detection scheme. Finally, we analyze the dynamics of the optoacoustic memory at different cryogenic temperatures in the range of 4.2–20 K and compare the findings to continuous wave measurements. The extended storage time is beneficial not only for photonic computing but also for Brillouin applications that require long phonon lifetimes, such as optoacoustic filters, true-time delay networks, and synthesizers in microwave photonics.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":null,"pages":null},"PeriodicalIF":7.0,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142448740","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 : 2024-10-17DOI: 10.1021/acsphotonics.4c01378
Xingyu Zhao, Nan Zhang, Liujian Qi, Bin Wang, Fan Tan, Chunlu Chang, Mingxiu Liu, Mengqi Che, Yaru Shi, Yahui Li, Yanze Feng, Dabing Li, Shaojuan Li
Broadband photodetectors based on a two-dimensional (2D) heterojunction have received tremendous attention in recent years and have broad application potential in biochemical analysis, optical communication, and other fields. The photodetectors based on the asymmetric Schottky junction have demonstrated attractive optoelectronic properties due to their ultralow dark current and improved photodetection properties. However, it is difficult to tune the Schottky barriers with 2D semiconductors due to the Fermi pinning effect or the large mismatch between the energy band structure of the 2D channel and the metal electrode. Herein, we demonstrate a broadband photodetector based on semimetal Td-MoTe2/bipolar semiconductor WSe2/Ti covering the visible-to-infrared wavelength. Kelvin probe force microscopy characterization reveals a well-matched energy band alignment between Td-MoTe2 and WSe2 that allows the Schottky barriers to be broadly modulated by the gate voltage, leading to a reconfigurable polarity transition of the photocurrent. The spatially resolved photocurrent mapping indicates that the asymmetric junction at both ends dominates the photocurrent generation at the different bias voltages. The gate voltage is applied to change the Fermi level of WSe2, which modulates the Schottky barrier and, thereby, improves carrier transport and photoelectric conversion capabilities. As a result, the device achieves a 417% improvement in responsivity and 1183% in detectivity at a light power of 1.2 mW/cm2. This work demonstrates the potential application of 2D van der Waals field-effect transistors with asymmetric Schottky contacts for broadband, high-performance, and tunable photodetection.
{"title":"Bipolar Tunable Field-Effect Transistor Based on the Td-MoTe2/WSe2 Heterojunction with Reconfigurable Polarity Transition for Enhanced Photodetection","authors":"Xingyu Zhao, Nan Zhang, Liujian Qi, Bin Wang, Fan Tan, Chunlu Chang, Mingxiu Liu, Mengqi Che, Yaru Shi, Yahui Li, Yanze Feng, Dabing Li, Shaojuan Li","doi":"10.1021/acsphotonics.4c01378","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c01378","url":null,"abstract":"Broadband photodetectors based on a two-dimensional (2D) heterojunction have received tremendous attention in recent years and have broad application potential in biochemical analysis, optical communication, and other fields. The photodetectors based on the asymmetric Schottky junction have demonstrated attractive optoelectronic properties due to their ultralow dark current and improved photodetection properties. However, it is difficult to tune the Schottky barriers with 2D semiconductors due to the Fermi pinning effect or the large mismatch between the energy band structure of the 2D channel and the metal electrode. Herein, we demonstrate a broadband photodetector based on semimetal <i>T</i><sub>d</sub>-MoTe<sub>2</sub>/bipolar semiconductor WSe<sub>2</sub>/Ti covering the visible-to-infrared wavelength. Kelvin probe force microscopy characterization reveals a well-matched energy band alignment between <i>T</i><sub>d</sub>-MoTe<sub>2</sub> and WSe<sub>2</sub> that allows the Schottky barriers to be broadly modulated by the gate voltage, leading to a reconfigurable polarity transition of the photocurrent. The spatially resolved photocurrent mapping indicates that the asymmetric junction at both ends dominates the photocurrent generation at the different bias voltages. The gate voltage is applied to change the Fermi level of WSe<sub>2</sub>, which modulates the Schottky barrier and, thereby, improves carrier transport and photoelectric conversion capabilities. As a result, the device achieves a 417% improvement in responsivity and 1183% in detectivity at a light power of 1.2 mW/cm<sup>2</sup>. This work demonstrates the potential application of 2D van der Waals field-effect transistors with asymmetric Schottky contacts for broadband, high-performance, and tunable photodetection.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":null,"pages":null},"PeriodicalIF":7.0,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142444360","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 : 2024-10-15DOI: 10.1021/acsphotonics.4c00687
Anindya Ghoshroy, James Davis, Adrian A. Moazzam, Roohollah Askari, Durdu Ö. Güney
Robust transmission of spatial, spectral, or temporal distributions of light through complex disordered media such as a turbulent atmosphere, biological tissue, or turbid media remains a critical obstacle in many research fields involving imaging, diagnosis, sensing, and communications. Inspired from a virtual-gain technique for loss compensation in metamaterials, active convolved illumination (ACI) has been recently proposed as a ubiquitous optical compensation technique to significantly enhance information transport and hence data acquisition across lossy, noisy, or distorting media. The enhancement is achieved with an auxiliary source, which is correlated with the ground truth and ideally, when superimposed with the latter, perfectly compensates for any distortion incurred during the transmission process. In this work, we propose the first framework to implement ACI for robust coherent light transmission through a turbulent atmosphere. The auxiliary source is formulated from a reciprocal space characterization of the speckle pattern from a guide star or pilot beam. The proposed method can maintain high-fidelity wave propagation under moderately anisoplanatic conditions with an impressive 20-fold enhancement compared to the resolution limit of the turbulent atmosphere. We outline potential strategies to extend the framework to include dynamic turbulence and scattering effects. This work introduces a powerful tool for robust light transmission through disordered media and potentially can be seamlessly integrated with existing techniques and further extended to the broad spectrum of statistical sciences.
{"title":"Enhancing Complex Light Beam Propagation in Turbulent Atmosphere with Active Convolved Illumination","authors":"Anindya Ghoshroy, James Davis, Adrian A. Moazzam, Roohollah Askari, Durdu Ö. Güney","doi":"10.1021/acsphotonics.4c00687","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c00687","url":null,"abstract":"Robust transmission of spatial, spectral, or temporal distributions of light through complex disordered media such as a turbulent atmosphere, biological tissue, or turbid media remains a critical obstacle in many research fields involving imaging, diagnosis, sensing, and communications. Inspired from a virtual-gain technique for loss compensation in metamaterials, active convolved illumination (ACI) has been recently proposed as a ubiquitous optical compensation technique to significantly enhance information transport and hence data acquisition across lossy, noisy, or distorting media. The enhancement is achieved with an auxiliary source, which is correlated with the ground truth and ideally, when superimposed with the latter, perfectly compensates for any distortion incurred during the transmission process. In this work, we propose the first framework to implement ACI for robust coherent light transmission through a turbulent atmosphere. The auxiliary source is formulated from a reciprocal space characterization of the speckle pattern from a guide star or pilot beam. The proposed method can maintain high-fidelity wave propagation under moderately anisoplanatic conditions with an impressive 20-fold enhancement compared to the resolution limit of the turbulent atmosphere. We outline potential strategies to extend the framework to include dynamic turbulence and scattering effects. This work introduces a powerful tool for robust light transmission through disordered media and potentially can be seamlessly integrated with existing techniques and further extended to the broad spectrum of statistical sciences.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":null,"pages":null},"PeriodicalIF":7.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142436439","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 : 2024-10-15DOI: 10.1021/acsphotonics.4c01563
Zihao Zhang, Yang Zhang, Xinghao Duan, Yi Zhang, Yue Dong, Junli Wang
The spatiotemporal mode-locking (STML) offers a viable solution to address the energy limit of the single-mode conventional soliton (SM-CS). While the potential for generating highly multimode conventional soliton lasers has been predicted, experimental demonstrations are still lacking. Moreover, existing STML systems have relied on conventional saturable absorbers (SAs), such as nonlinear polarization evolution and material SAs, which restrict output parameters due to complex spatial structures or low damage thresholds. To the best of our knowledge we report the first experimental realization of a multimode CS laser (dominated by the LP21 mode) using a spatial alignment structure (SAS). This SAS consists of two aspherical lenses, which function simultaneously as an SA, spatial filter, and attenuator. This configuration enhances system compactness and introduces additional degrees of freedom for adjustment. By modifying the alignment of the SAS, various MM nonlinear dynamics can be observed, including center wavelength shifting, spectrum and spatial evolution, harmonic STML, soliton molecules, and a multicolor STML. Our system shows clear advantages in pulse energy (>3 nJ), stability, and tunability compared to other 1.5 μm STML lasers. Incorporating a SM output coupler enables the simultaneous generation of both a SM-CS and a multimode convention soliton (MM-CS), which exhibit similar spectral profiles and pulse durations approaching the transform limit. Our results indicate that soliton-like pulse shaping is crucial for achieving multimode soliton pulses. The pulse energy of SM-CS, measured at 7.05 nJ (35.25 nJ intracavity pulse energy), represents nearly a 10-fold increase compared to previous SM-CS fiber lasers. This STML system with the new SA offers a valuable platform for exploring complex multimode nonlinear dynamics and provides a promising approach for achieving high-energy soliton lasers.
时空模式锁定（STML）为解决单模传统孤子（SM-CS）的能量极限问题提供了一种可行的解决方案。虽然人们已经预测了产生高度多模传统孤子激光器的潜力，但仍然缺乏实验证明。此外，现有的 STML 系统依赖于传统的可饱和吸收体（SA），如非线性偏振演化和材料 SA，由于空间结构复杂或损伤阈值较低，限制了输出参数。据我们所知，我们报告了利用空间排列结构（SAS）首次实验实现的多模 CS 激光器（以 LP21 模式为主）。这种 SAS 由两个非球面透镜组成，可同时用作空间对准结构、空间滤波器和衰减器。这种配置提高了系统的紧凑性，并增加了调整的自由度。通过改变 SAS 的排列，可以观测到各种 MM 非线性动力学，包括中心波长移动、光谱和空间演变、谐波 STML、孤子分子和多色 STML。与其他 1.5 μm STML 激光器相比，我们的系统在脉冲能量（3 nJ）、稳定性和可调谐性方面具有明显优势。结合 SM 输出耦合器，可以同时产生 SM-CS 和多模约定孤子 (MM-CS)，它们表现出相似的光谱轮廓和接近变换极限的脉冲持续时间。我们的研究结果表明，类似于孤子的脉冲整形对于实现多模孤子脉冲至关重要。测得的 SM-CS 脉冲能量为 7.05 nJ（腔内脉冲能量为 35.25 nJ），与之前的 SM-CS 光纤激光器相比提高了近 10 倍。这种带有新型 SA 的 STML 系统为探索复杂的多模非线性动力学提供了一个宝贵的平台，并为实现高能孤子激光器提供了一种前景广阔的方法。
{"title":"Spatiotemporal Mode-Locked Multimode Soliton Fiber Laser Based on a Spatial Alignment Structure","authors":"Zihao Zhang, Yang Zhang, Xinghao Duan, Yi Zhang, Yue Dong, Junli Wang","doi":"10.1021/acsphotonics.4c01563","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c01563","url":null,"abstract":"The spatiotemporal mode-locking (STML) offers a viable solution to address the energy limit of the single-mode conventional soliton (SM-CS). While the potential for generating highly multimode conventional soliton lasers has been predicted, experimental demonstrations are still lacking. Moreover, existing STML systems have relied on conventional saturable absorbers (SAs), such as nonlinear polarization evolution and material SAs, which restrict output parameters due to complex spatial structures or low damage thresholds. To the best of our knowledge we report the first experimental realization of a multimode CS laser (dominated by the LP21 mode) using a spatial alignment structure (SAS). This SAS consists of two aspherical lenses, which function simultaneously as an SA, spatial filter, and attenuator. This configuration enhances system compactness and introduces additional degrees of freedom for adjustment. By modifying the alignment of the SAS, various MM nonlinear dynamics can be observed, including center wavelength shifting, spectrum and spatial evolution, harmonic STML, soliton molecules, and a multicolor STML. Our system shows clear advantages in pulse energy (>3 nJ), stability, and tunability compared to other 1.5 μm STML lasers. Incorporating a SM output coupler enables the simultaneous generation of both a SM-CS and a multimode convention soliton (MM-CS), which exhibit similar spectral profiles and pulse durations approaching the transform limit. Our results indicate that soliton-like pulse shaping is crucial for achieving multimode soliton pulses. The pulse energy of SM-CS, measured at 7.05 nJ (35.25 nJ intracavity pulse energy), represents nearly a 10-fold increase compared to previous SM-CS fiber lasers. This STML system with the new SA offers a valuable platform for exploring complex multimode nonlinear dynamics and provides a promising approach for achieving high-energy soliton lasers.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":null,"pages":null},"PeriodicalIF":7.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142436441","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 : 2024-10-15DOI: 10.1021/acsphotonics.4c01586
Xuanyu Ren, Xinxin He, Zhan Duan, Xuyang An, Yang Li, Feng Gao, Jia Zhang, PingAn Hu
The optical synaptic devices, inspired by the human visual system and capable of emulating biological synaptic behaviors, have demonstrated significant potential for artificial vision applications. However, contemporary optical synaptic devices are hindered by several limitations, including a narrow response range, intricate structures, compromised stability, and substantial energy demands. Herein, large single-crystal Bi2O2Se nanosheets with selenium vacancies (Bi2O2Se–VSe) were synthesized via physical vapor deposition. Based on the Bi2O2Se–VSe nanosheet, a self-powered, broadband optical synaptic device was developed simply by a straightforward asymmetric contact approach. The device proficiently replicates synaptic functionalities without any electrical power requirement. Furthermore, an artificial vision system comprising a 5 × 5 array of self-powered optical synaptic devices was constructed. Under illumination at wavelengths of 350, 532, and 1050 nm for 100 s, the intensity of the image pattern can be kept at a high memory level of 94.91%, 44.92%, and 12.83% after attenuation of 100 s, which demonstrates the excellent image sensing, learning, and memory storage properties. This research paves the way for further exploration of optical synaptic devices and contributes novel insights into the development of artificial vision systems.
{"title":"Self-Powered and Broadband Optical Synapse Device Based on Se-Vacancy Bi2O2Se for Artificial Vision System Application","authors":"Xuanyu Ren, Xinxin He, Zhan Duan, Xuyang An, Yang Li, Feng Gao, Jia Zhang, PingAn Hu","doi":"10.1021/acsphotonics.4c01586","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c01586","url":null,"abstract":"The optical synaptic devices, inspired by the human visual system and capable of emulating biological synaptic behaviors, have demonstrated significant potential for artificial vision applications. However, contemporary optical synaptic devices are hindered by several limitations, including a narrow response range, intricate structures, compromised stability, and substantial energy demands. Herein, large single-crystal Bi<sub>2</sub>O<sub>2</sub>Se nanosheets with selenium vacancies (Bi<sub>2</sub>O<sub>2</sub>Se–V<sub>Se</sub>) were synthesized via physical vapor deposition. Based on the Bi<sub>2</sub>O<sub>2</sub>Se–V<sub>Se</sub> nanosheet, a self-powered, broadband optical synaptic device was developed simply by a straightforward asymmetric contact approach. The device proficiently replicates synaptic functionalities without any electrical power requirement. Furthermore, an artificial vision system comprising a 5 × 5 array of self-powered optical synaptic devices was constructed. Under illumination at wavelengths of 350, 532, and 1050 nm for 100 s, the intensity of the image pattern can be kept at a high memory level of 94.91%, 44.92%, and 12.83% after attenuation of 100 s, which demonstrates the excellent image sensing, learning, and memory storage properties. This research paves the way for further exploration of optical synaptic devices and contributes novel insights into the development of artificial vision systems.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":null,"pages":null},"PeriodicalIF":7.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142439325","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 : 2024-10-11DOI: 10.1021/acsphotonics.4c01406
Yang Liu, Yubo Wang, Xiyang Wei, Hao Liu, Yongfang Zhang
The characteristics of the host in a liquid-crystal laser that enable it to emit light are of critical importance in determining the potential applications of such devices. The incorporation of nanomaterials into the host, which incorporates liquid crystals (LCs) to form an assembly, enhances their birefringence and contributes to the dipole moment, thereby reducing pump energy consumption. In this research, silver nanoflakes (Ag-NFs) were blended into the cholesteric liquid crystal (CLC) hosts (CLCs-host), resulting in their helical twisting. The incorporation of a small quantity of Ag-NFs not only enhanced the reflection of the hybrid but also optimized the utilization of pump energy to induce highly brightened lasing due to their excellent localized surface polarization resonance. The liquid-crystal-laser fabricated by blending 0.10 wt % Ag-NFs into polymer-stabilized CLCs (PSCLCs) containing 1 wt % reactive mesogens has been demonstrated to exhibit a lower pump energy consumption at 0.291 μJ/pulse. Moreover, the laser exhibited a higher lasing intensity by 16.2% improvement, superior time-luminance stability, and greater thermal resistance within the 26–38 °C range. The findings of this research contribute to the advancement of random laser technology in a variety of fields and facilitate the development of high-performance optoelectronic devices.
{"title":"Enhanced Laser Emission by Incorporating Helically Twisted Silver Nanoflakes within Polymer-Stabilized Cholesteric Liquid Crystals","authors":"Yang Liu, Yubo Wang, Xiyang Wei, Hao Liu, Yongfang Zhang","doi":"10.1021/acsphotonics.4c01406","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c01406","url":null,"abstract":"The characteristics of the host in a liquid-crystal laser that enable it to emit light are of critical importance in determining the potential applications of such devices. The incorporation of nanomaterials into the host, which incorporates liquid crystals (LCs) to form an assembly, enhances their birefringence and contributes to the dipole moment, thereby reducing pump energy consumption. In this research, silver nanoflakes (Ag-NFs) were blended into the cholesteric liquid crystal (CLC) hosts (CLCs-host), resulting in their helical twisting. The incorporation of a small quantity of Ag-NFs not only enhanced the reflection of the hybrid but also optimized the utilization of pump energy to induce highly brightened lasing due to their excellent localized surface polarization resonance. The liquid-crystal-laser fabricated by blending 0.10 wt % Ag-NFs into polymer-stabilized CLCs (PSCLCs) containing 1 wt % reactive mesogens has been demonstrated to exhibit a lower pump energy consumption at 0.291 μJ/pulse. Moreover, the laser exhibited a higher lasing intensity by 16.2% improvement, superior time-luminance stability, and greater thermal resistance within the 26–38 °C range. The findings of this research contribute to the advancement of random laser technology in a variety of fields and facilitate the development of high-performance optoelectronic devices.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":null,"pages":null},"PeriodicalIF":7.0,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142405043","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 : 2024-10-10DOI: 10.1021/acsphotonics.4c00904
Zhendong Luo, Huwang Hou, Ting Meng, Yiming Li, Tao Wang, Yanji Yi, Lianjie Xu, Zhiyu Chen, Hongmei Zhong, Ye Feng, Peng Zhang, Yang Zhao
The optomechanical uncooled infrared (IR) detector, based on the bimaterial microcantilever thermal deformation, has proved to have great potential due to the ability to measure IR using visible-spectral-range components. However, like most types of detectors, they encounter the common limitation of a low fill factor, leading to an inefficient utilization of light energy. The metalens, with a compact footprint, high design flexibility, and MEMS (microelectromechanical systems) compatibility, is expected to be integrated with IR detectors to enhance performance. Here, we present the design, fabrication, and characterization of a monolithic integration of a long-wavelength infrared (LWIR) micrometalens array and an optomechanical IR detector. A microfabrication process was developed to successfully prepare such an optomechanical IR detector with a monolithically integrated micrometalens array, where the micrometalens array was directly fabricated on the back of the detector substrate. Experimental results demonstrate that the integration of the micrometalens array markedly amplifies the responsivity of the optomechanical detector within the 8–14 μm wavelength band, achieving an enhancement of 81.8%.
{"title":"Optomechanical Infrared Detector Monolithically Integrated with Micro-Metalens Array","authors":"Zhendong Luo, Huwang Hou, Ting Meng, Yiming Li, Tao Wang, Yanji Yi, Lianjie Xu, Zhiyu Chen, Hongmei Zhong, Ye Feng, Peng Zhang, Yang Zhao","doi":"10.1021/acsphotonics.4c00904","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c00904","url":null,"abstract":"The optomechanical uncooled infrared (IR) detector, based on the bimaterial microcantilever thermal deformation, has proved to have great potential due to the ability to measure IR using visible-spectral-range components. However, like most types of detectors, they encounter the common limitation of a low fill factor, leading to an inefficient utilization of light energy. The metalens, with a compact footprint, high design flexibility, and MEMS (microelectromechanical systems) compatibility, is expected to be integrated with IR detectors to enhance performance. Here, we present the design, fabrication, and characterization of a monolithic integration of a long-wavelength infrared (LWIR) micrometalens array and an optomechanical IR detector. A microfabrication process was developed to successfully prepare such an optomechanical IR detector with a monolithically integrated micrometalens array, where the micrometalens array was directly fabricated on the back of the detector substrate. Experimental results demonstrate that the integration of the micrometalens array markedly amplifies the responsivity of the optomechanical detector within the 8–14 μm wavelength band, achieving an enhancement of 81.8%.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":null,"pages":null},"PeriodicalIF":7.0,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142398588","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 : 2024-10-10DOI: 10.1021/acsphotonics.4c01641
Yu Huang, Pei Zhou, Kuenyao Lau, Nianqiang Li
Optical chaos, especially in the form of parallel temporal/spatial chaos, presents a highly efficient approach for high-throughput information processing in diverse applications such as optical communication and reinforcement learning. However, despite these advancements, current approaches mainly focus on achieving enhanced single-channel performance or compromised multichannel realization (e.g., sacrificing the bandwidth, individual control, or system complexity). In this study, an integrated laser array with intensity-modulated optical injection is exclusively fabricated and employed to produce parallel optical chaos exhibiting independent and wideband characteristics. We demonstrate in a proof-of-concept experiment that allows for feasibly generating four parallel chaotic signals with a bandwidth exceeding 30 GHz, which is only limited by the detection devices. Benefiting from the high-frequency oscillations and faster dynamics of the on-chip laser array, the physical (physical-based pseudo) random bit generation rate can reach up to 1.6 Tb/s (15.04 Tb/s) by leveraging two postprocessing methods. We further expand the superiority of our proposed approach by demonstrating parallel benchmark decision-making, where we testify both experimentally and numerically that our fabricated laser array system outperforms the existing conventional approaches. This work explores novel avenues for high-throughput information processing by deploying chip-scale parallel chaotic systems.
{"title":"Parallel Wideband Chaos Generation System for Advancing High-Throughput Information Processing Based on an Array of Four Distributed Feedback Lasers","authors":"Yu Huang, Pei Zhou, Kuenyao Lau, Nianqiang Li","doi":"10.1021/acsphotonics.4c01641","DOIUrl":"https://doi.org/10.1021/acsphotonics.4c01641","url":null,"abstract":"Optical chaos, especially in the form of parallel temporal/spatial chaos, presents a highly efficient approach for high-throughput information processing in diverse applications such as optical communication and reinforcement learning. However, despite these advancements, current approaches mainly focus on achieving enhanced single-channel performance or compromised multichannel realization (e.g., sacrificing the bandwidth, individual control, or system complexity). In this study, an integrated laser array with intensity-modulated optical injection is exclusively fabricated and employed to produce parallel optical chaos exhibiting independent and wideband characteristics. We demonstrate in a proof-of-concept experiment that allows for feasibly generating four parallel chaotic signals with a bandwidth exceeding 30 GHz, which is only limited by the detection devices. Benefiting from the high-frequency oscillations and faster dynamics of the on-chip laser array, the physical (physical-based pseudo) random bit generation rate can reach up to 1.6 Tb/s (15.04 Tb/s) by leveraging two postprocessing methods. We further expand the superiority of our proposed approach by demonstrating parallel benchmark decision-making, where we testify both experimentally and numerically that our fabricated laser array system outperforms the existing conventional approaches. This work explores novel avenues for high-throughput information processing by deploying chip-scale parallel chaotic systems.","PeriodicalId":23,"journal":{"name":"ACS Photonics","volume":null,"pages":null},"PeriodicalIF":7.0,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142397805","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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