Author Affiliations
Abstract
1 Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, China
2 State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Semiconductors (College of Integrated Circuits), Hunan University, Changsha 410082, China
3 e-mail: liuxq@hnu.edu.cn
4 e-mail: liaolei@whu.edu.cn
5 e-mail: zouxuming@hnu.edu.cn
With the progress of both photonics and electronics, optoelectronic synapses are considered potential candidates to challenge the von Neumann bottleneck and the field of visual bionics in the era of big data. They are also regarded as the basis for integrated artificial neural networks (ANNs) owing to their flexible optoelectronic tunable properties such as high bandwidth, low power consumption, and high-density integration. Over the recent years, following the emergence of metal halide perovskite (MHP) materials possessing fascinating optoelectronic properties, novel MHP-based optoelectronic synaptic devices have been exploited for numerous applications ranging from artificial vision systems (AVSs) to neuromorphic computing. Herein, we briefly review the application prospects and current status of MHP-based optoelectronic synapses, discuss the basic synaptic behaviors capable of being implemented, and assess their feasibility to mimic biological synapses. Then, we focus on the two-terminal optoelectronic synaptic memristors and three-terminal transistor synaptic phototransistors (SPTs), the two essential apparatus structures for optoelectronic synapses, expounding their basic features and operating mechanisms. Finally, we summarize the recent applications of optoelectronic synapses in neuromorphic systems, including neuromorphic computing, high-order learning behaviors, and neuromorphic vision systems, outlining their potential opportunities and future development directions as neuromorphic devices in the field of artificial intelligence (AI).
Photonics Research
2023, 11(5): 787
Author Affiliations
Abstract
1 State Key Laboratory of High Power Semiconductor Lasers, College of Physics, Changchun University of Science and Technology, Changchun 130022, China
2 State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Semiconductors (College of Integrated Circuits), Hunan University, Changsha 410082, China
3 Department of Laser Photoelectric Technology, Southwest Institute of Technical Physics, Chengdu 610041, China
4 Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China
5 Zhongshan Institute of Changchun University of Science and Technology, Zhongshan 442000, China
We developed a hybrid structure photodetector combining one-dimensional (1D) inorganic GaAs nanowires and two-dimensional (2D) organic perovskite materials, which can achieve various performance enhancements using a relatively simple structure. Via the optical absorption enhancement of perovskite and the type-II energy band structure formed by the heterostructure, the responsivity and detectivity of the photodetector from ultraviolet (UV) to visible (Vis) wavelengths are significantly enhanced, reaching 75 A/W and Jones, respectively. The response time of the photodetector was significantly decreased by 3 orders, from 785 ms to 0.5 ms, and the dark current was further reduced to 237 fA. A photodetector was prepared with enhanced responsivity and ultrafast response time in the multiband region from the UV to Vis wavelength. To the best of our knowledge, this is the first time to combine inorganic III-V GaAs nanomaterials with organic perovskite materials, which verifies the effective combination of inorganic and organic materials in a mixed dimension. The excellent photoelectric performance of the perovskite/GaAs-nanowire hybrid structure photodetector makes it a potential candidate material for a wide range of photoelectric applications such as multiband photodetection.
Photonics Research
2023, 11(4): 541
1 华中科技大学武汉国家光电研究中心，湖北 武汉 430074
2 武汉长进激光技术有限公司，湖北 武汉 430206
为了提升铒镱共掺光纤的抗辐照性能，以适用于远距离太空通信应用，采用改进的化学气相沉积(MCVD)方法制备了抗辐照铒镱共掺光纤。在常温下使用Co60辐射源对自研铒镱共掺光纤进行剂量为300 Gy和1000 Gy、平均剂量率为0.2 Gy/s的辐照。在940 nm和1550 nm处，该光纤在300 Gy辐照剂量下的辐致吸收(RIA)分别为0.10 dB/m和0.19 dB/m，在1000 Gy辐照剂量下的RIA分别为0.46 dB/m和0.37 dB/m。搭建了铒镱共掺光纤放大器(EYDFA)进行增益测试，采用输入功率为40 mW的1550 nm信号与940 nm的泵浦源，泵浦功率为7.3 W时其辐致增益变化(RIGV)分别为0.2 dB(300 Gy)和0.7 dB(1000 Gy)。
光纤光学 铒镱共掺光纤设计与制备 抗辐照性能 光纤通信 铒镱共掺光纤放大器 中国激光
2022, 49(22): 2215001
1 华中科技大学武汉光电国家研究中心，湖北 武汉 430074
2 武汉长进激光技术有限公司，湖北 武汉 430206
采用改进的化学气相沉积工艺结合溶液掺杂技术成功制备了一种低数值孔径部分掺杂纺锤形光纤。该光纤的数值孔径约为0.05，镱离子在纤芯中的掺杂直径比约为77%，光纤两端纤芯和包层的直径分别为25 μm和400 μm，中间部分纤芯和包层的直径分别为37.5 μm和600 μm。搭建976 nm双端泵浦光纤放大器，该光纤最终实现了4.188 kW 的单模激光输出，斜率效率为82.8%，最高功率下的光束质量因子约为1.3，其输出功率的继续提升受限于受激拉曼散射效应。
光纤光学 掺镱光纤 光纤设计 横向模式不稳定 受激拉曼散射 光束质量 中国激光
2022, 49(13): 1315002
1 华中科技大学武汉光电国家研究中心，湖北 武汉 430074
2 武汉长进激光技术有限公司，湖北 武汉 430223
随着激光雷达技术的快速发展，激光雷达在**及民用领域中的应用不断增多。保偏铒镱共掺光纤是1.5 μm激光雷达重要的增益介质，对其性能有重要的影响。成功制备出10 μm/128 μm保偏铒镱共掺光纤，其双折射系数为1.29×10－4，在1310 nm处的消光比为24 dB@4 m。基于该光纤搭建了全保偏全光纤主振荡功率放大系统，实验结果显示，当信号波长为1551 nm，光纤长度为7.5 m，940 nm泵浦功率为16.5 W时，输出功率为5.8 W，斜率效率达36%，输出激光的消光比为21 dB。该保偏铒镱共掺光纤具有优异的激光性能，为1.5 μm激光雷达系统的国产化提供了新的解决方案。
光纤光学 光纤激光器 铒镱共掺 激光雷达 保偏光纤 中国激光
2022, 49(12): 1206006
Author Affiliations
Abstract
1 Key Laboratory for Micro-Nano Optoelectronic Devices of Ministry of Education, School of Physics and Electronics, Hunan University, Changsha 410082, People’s Republic of China
2 State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, School of Mechanical and Vehicle Engineering, Hunan University, Changsha 410082, People’s Republic of China
Memristors have attracted tremendous interest in the fields of high-density memory and neuromorphic computing. However, despite the tremendous efforts that have been devoted over recent years, high operating voltage, poor stability, and large device variability remain key limitations for its practical application and can be partially attributed to the un-optimized interfaces between electrodes and the channel material. We demonstrate, for the first time, a van der Waals (vdW) memristor by physically sandwiching pre-fabricated metal electrodes on both sides of the two-dimensional channel material. The atomically flat bottom electrode ensures intimate contact between the channel and electrode (hence low operation voltage), and the vdW integration of the top electrode avoids the damage induced by aggressive fabrication processes (e.g. sputtering, lithography) directly applied to the channel material, improving device stability. Together, we demonstrate memristor arrays with a high integration density of 1010 cm.2, high stability, and the lowest set/reset voltage of 0.12 V/0.04 V, which is a record low value for all 2D-based memristors, as far as we know. Furthermore, detailed characterizations are conducted to confirm that the improved memristor behavior is the result of optimized metal/channel interfaces. Our study not only demonstrates robust and low voltage memristor, but also provides a general electrode integration approach for other memristors, such as oxide based memristors, that have previously been limited by non-ideal contact integration, high operation voltage and poor device stability.
2D-material robust memristor ultra-low threshold atomically flat interfaces International Journal of Extreme Manufacturing
2021, 3(4): 045103
1 华中科技大学武汉国家光电研究中心, 湖北 武汉 430074
2 武汉长进激光技术有限公司, 湖北 武汉 430206
为了保证掺铒光纤在辐照环境下的工作性能与寿命,采用改进的化学气相沉积(MCVD)方法制备了C波段抗辐照掺铒光纤。在常温下使用 60Co辐射源对自研掺铒光纤进行累积剂量为1500 Gy、平均剂量率为0.2 Gy/s的辐照,结果发现,该光纤在980 nm和1550 nm处的辐致损耗(RIA)分别为1.4 dB/m和0.8 dB/m。搭建了掺铒光纤放大器(EDFA)进行增益测试,测试过程中采用输入功率为-20 dBm的1550 nm信号与波长为980 nm的泵浦源。测试结果表明,在100 mW和500 mW泵浦功率下,1550 nm处的辐致增益变化(RIGV)分别为0.8 dB和0.2 dB。
光纤光学 掺铒光纤 抗辐照 光纤通信 掺铒光纤放大器 中国激光
2021, 48(20): 2015001
1 华中科技大学武汉光电国家研究中心, 湖北 武汉 430074
2 武汉长进激光技术有限公司, 湖北 武汉 430206
搭建了基于声光调Q种子源的主振荡高功率放大(MOPA)系统。采用自主设计和制备的大模场双包层(100μm /400μm)有源光纤,通过两级放大,在重复频率为60kHz、脉冲宽度为150ns的条件下实现了平均功率为1000W的脉冲输出,斜率效率为72.5%,光谱显示无剩余泵浦光和寄生振荡,同时没有受激拉曼散射效应。此时的脉冲宽度展宽到260ns,单脉冲能量为16.7mJ。这是采用国产光纤实现脉冲激光器平均功率突破1000W的首次报道。
光纤光学 脉冲光纤激光器 主振荡功率放大 高功率脉冲放大
华中科技大学武汉光电国家研究中心, 湖北 武汉 430074
基于自主研发的100/400双包层掺镱有源石英光纤,搭建了高功率主振荡功率放大(MOPA)结构纳秒调Q光纤激光器,重复频率30~60 kHz可调谐。系统中心波长为1064.08 nm。采用976 nm激光泵浦,在60 kHz时实现平均功率761 W的输出,单脉冲能量为12.6 mJ,斜率效率为83.4%,光束质量 Mx2=9.82, My2=9.02;30 kHz下平均功率为526 W,单脉冲能量为17.5 mJ,斜率效率为85%,光束质量 Mx2=8.67, My2=8.57。该光纤是目前报道的高重复频率下获得的平均功率和单脉冲能量最高的国产光纤。
激光器 脉冲光纤激光器 掺镱光纤 单脉冲能量 主振荡功率放大 中国激光
2019, 46(12): 1215002
华中科技大学武汉光电国家实验室, 湖北 武汉 430074
光纤激光器的输出功率达到一定阈值后, 激光器中会出现模式不稳定效应, 该效应会对激光器的输出功率和光束质量造成严重影响, 限制了大功率激光器的进一步应用。研究大功率光纤激光器中的模式不稳定机理及抑制方法, 这对光纤激光器输出功率的进一步提高具有重要意义。系统介绍了模式不稳定机理, 并总结了一些模式不稳定的抑制方法。
激光光学 掺镱光纤 光纤激光器 模式不稳定 光子暗化 激光与光电子学进展
2017, 54(8): 080001
