Author Affiliations
Abstract
Grünberg Research Centre, College of Telecommunications and Information Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210003, China
To date, fluorescence imaging systems have all relied on at least one beam splitter (BS) to ensure the separation of excitation light and fluorescence. Here, we reported SiO2/TiO2 multi-layer long pass filter integrated GaN LED. It is considered as the potential source for imaging systems. Experimental results indicate that the GaN LED shows blue emission peaked at 470.3 nm and can be used to excite dye materials. Integrating with a long pass filter (550 nm), the light source can be used to establish a real-time fluorescence detection for dyes that emit light above 550 nm. More interestingly, with this source, a real-time imaging system with signature words written with the dyes, such as ‘N J U P T’, can be converted into CCD images. This work may lead to a new strategy for integrating light sources and BS mirrors to build mini and smart fluorescence imaging systems.
GaN LED self-filtering illumination source fluorescence imaging 
Chinese Optics Letters
2023, 21(1): 011101
作者单位
摘要
中国科学院上海技术物理研究所 中科院红外成像材料与器件重点实验室,上海 200083
针对不同项目研制过程中碲镉汞线列光导器件在筛选测试和应用中出现的失效模式进行了归纳和总结,并综合碲镉汞材料参数、器件结构尺寸、器件物理、器件制备工艺和器件测试等几个方面因素对器件失效的可能原因进行了分析,首次提出碲镉汞线列光导器件的优值因子作为失效判据,为进一步理解碲镉汞线列光导器件的物理机理以及更好优化器件的筛选过程提供了参考,为碲镉汞线列光导器件应用中出现的失效问题提供了分析和解决的方向。
碲镉汞 光导器件 失效分析 HgCdTe photoconductive detector photoconductor failure analysis 
红外与毫米波学报
2022, 41(6): 1009
Author Affiliations
Abstract
1 Key Laboratory of Computer Vision and System of Ministry of Education, Tianjin Key Laboratory of Intelligence Computing and Novel Software Technology, Tianjin University of Technology, Tianjin 300384, China
2 The MOE Key Laboratory of Weak-Light Nonlinear Photonics, Nankai University, Tianjin 300457, China
It is novel to apply three-dimensional (3D) light field imaging technology to recognize two-dimensional (2D) fake pedestrians. In this paper, we propose a parallel support vector machine (SVM) method based on 3D light field imaging (light field camera) and machine learning techniques. A light field (LF) camera with robust sensors, which is able to record rich 3D information, is used as hardware equipment. Histogram of oriented gradient (HOG) feature extraction algorithm and SVM classification method are used to recognize the real and 2D fake pedestrians efficiently. Besides, we carry out an experiment on our improved LF pedestrian dataset. The experimental results of parameter optimization study show that in the case of 400 training samples (200 positive samples and 200 negative samples), 120 to 420 testing samples, and an HOG cellsize as 8×8, the best recognition accuracy with polynomial kernel function is improved by more than 2% compared with the previous method. The best accuracy is 99.17%. Otherwise, the recognition accuracy of more than 98.00% will be obtained even under other experimental conditions.
光电子快报(英文版)
2022, 18(1): 48
郑江鹏 1余平 1赵萌 1,*石凡 1,*[ ... ]陈胜勇 1
作者单位
摘要
1 学习型智能系统教育部工程研究中心, 天津理工大学计算机科学与工程学院, 天津 300384
2 天津医科大学医学检验学院, 天津 300203
由于低信噪比的小样本太赫兹光谱的可区分性特征提取困难和样本量过少带来的深度学习模型自身的过拟合问题,将太赫兹光谱与深度学习相结合应用于心肌淀粉样变检测仍面临挑战。本文提出了一种基于多模块顺序级联的分类模型,用于心肌淀粉样变在算法层面的实时检测。首先,采集了少量的低信噪比太赫兹光谱并对其进行预处理。其次,构建了一个基于卷积降噪自编码器、多尺度特征提取模块、密集连接模块的深度学习模型。最后,通过五折交叉验证策略进行病变预测,以获得稳定、可靠的结果。 10次独立重复实验和对比实验结果表明,该方法能对含噪光谱进行准确、稳定的分类,且其综合指标更优。不同样本量下的实验表明,本方法对样本量变化具有适应性:数据量为100时可达到95%的准确率;数据量仅为20时,该模型仍能取得70%的准确率。该项工作对心肌淀粉样变的实时、高效、安全诊断具有重要意义。
太赫兹光谱 心肌淀粉样变 低信噪比 小样本 深度学习 terahertz spectroscopy myocardial amyloidosis low signal to noise ratio a small number of samples deep learning 
中国光学
2022, 15(3): 443
作者单位
摘要
1 江苏理工学院 机械工程学院,江苏 常州 213001
2 东南大学 机械工程学院,江苏 南京 211189
针对当前视觉检测系统LED光源照度优化研究中存在的照度效果评价因素单一、照度优化方法通用性不足等问题,以芯片封装质量视觉检测为例,提出一种基于改进樽海鞘算法的LED光源照度优化方法。该方法在单个LED光源照度数学模型基础上,建立标准条形LED阵列光源照度数学模型,获取条形LED阵列在任意空间位姿与被测面的照度值;基于照度均匀度、照度梯度变化与对中度、平均照度、目标与背景区分度等因素建立平面照度效果评价函数;提出改进樽海鞘算法,通过改进算法收敛系数、速度、领导者与追随者位置等更新策略,增强区域搜索的多样性;应用改进樽海鞘算法对平面照度效果评价函数进行优化求解,获取具有最优照度效果的空间位姿参数。实验结果表明:考察优化区域的相对照度分布,文中提出的LED光源照度优化方法所得照度分布与实际测量所得照度分布结果基本一致,目标区域理论照度均匀度在98.78%以上,误差在5.57%以内。因此文中提出方法优化目标合理,可用于视觉检测系统具有最优照度效果时光源位姿信息参数的获取。
照度建模 改进樽海鞘算法 优化计算 均匀光照 LED阵列 illumination modeling improved Salp swarm algorithm optimization calculation illumination uniformity LED array 
红外与激光工程
2021, 50(12): 20210745
作者单位
摘要
特种光纤与光接入网重点实验室,特种光纤与先进通信国际合作联合实验室,上海先进通信与数据科学研究院,上海大学,上海 200444
本文提出了一种可以实现光纤高阶模式(HOM)在激光腔内振荡的锁模掺镱光纤激光器。通过使用一对级联的模式选择耦合器(MSC)作为有效的模式转换器,获得光纤锁模激光腔内HOM产生。其中,制备的MSC中心波长为1064 nm,可实现80 nm的模式转换带宽和94%的高阶模式纯度。通过搭建掺镱锁模光纤激光器,实验获得了3 dB谱宽7.4 nm、脉冲重复频率10.9 MHz、射频信噪比55 dB的锁模脉冲激光,输出功率的斜率效率为2.3%。实验证明,这种方法可在激光器内部通过模式级联转换,且能参与腔内锁模过程获得脉冲HOM激光。
模式选择耦合器 高阶模式 掺镱光纤 锁模光纤激光器 mode-selective couplers high-order mode Yb-doped fibers mode-locking fiber lasers 
光电工程
2020, 47(11): 200040
作者单位
摘要
上海大学先进通信与数据科学研究院, 特种光纤与光接入网重点实验室, 特种光纤与先进通信国际合作联合实验室, 上海 200444
基于腔内的模式选择耦合器(MSC),报道了一种输出模式可切换的调Q脉冲掺铒光纤激光器。通过布拉格光栅和MSC的共同作用,实现输出波长的选择和不同模式间的转换。由于MSC具有模式分离特性且激光腔具有双支路输出配置,通过调整腔内损耗可以实现对激光输出不同模式间的切换,成功地观察到了同时具有线偏振模式(LP01模式和LP11模式)的双波长调Q脉冲输出,该模式可切换激光器可以应用在通信、粒子捕获等领域。
激光器 调Q光纤激光器 双波长 可调横模 少模布拉格光栅 lasers Q-switched fiber laser dual-wavelength switchable transverse mode few-mode fiber Bragg grating 
中国激光
2020, 47(12): 1201001
Author Affiliations
Abstract
1 Key Laboratory of Specialty Fiber Optics and Optical Access Networks, Joint International Research Laboratory of Specialty Fiber Optics and Advanced Communication, Shanghai University, Shanghai 200444, China
2 Department of Electronic Engineering, School of Information Science and Engineering, Xiamen University, Xiamen 361005, China
3 Shenzhen Key Laboratory of Laser Engineering, Shenzhen University, Shenzhen 518060, China
4 e-mail: ffpang@shu.edu.cn
Temporal and spatial resonant modes are always possessed in physical systems with energy oscillation. In ultrafast fiber lasers, enormous progress has been made toward controlling the interactions of many longitudinal modes, which results in temporally mode-locked pulses. Recently, optical vortex beams have been extensively investigated due to their quantized orbital angular momentum, spatially donut-like intensity, and spiral phase front. In this paper, we have demonstrated the first to our knowledge observation of optical vortex mode switching and their corresponding pulse evolution dynamics in a narrow-linewidth mode-locked fiber laser. The spatial mode switching is achieved by incorporating a dual-resonant acousto-optic mode converter in the vortex mode-locked fiber laser. The vortex mode-switching dynamics have four stages, including quiet-down, relaxation oscillation, quasi mode-locking, and energy recovery prior to the stable mode-locking of another vortex mode. The evolution dynamics of the wavelength shifting during the switching process are observed via the time-stretch dispersion Fourier transform method. The spatial mode competition through optical nonlinearity induces energy fluctuation on the time scale of ultrashort pulses, which plays an essential role in the mode-switching dynamic process. The results have great implications in the study of spatial mode-locking mechanisms and ultrashort laser applications.
Photonics Research
2020, 8(7): 07001203
作者单位
摘要
上海大学特种光纤与光接入网重点实验室, 特种光纤与先进通信国际合作联合实验室, 上海先进通信与数据科学研究院, 上海 200444
对模式选择耦合器、声致光纤光栅等全光纤模式转换器件的工作原理进行总结,并结合锁模光纤激光器和模式转换器件的优势,简单高效地产生了超快矢量光束和涡旋光束,得到的超快高阶模式激光具有峰值功率高、模式纯度高等特点。实验证明了模式转换器件的快速响应特性和宽带模式转换特性,并指出了其未来的发展方向和应用前景。
光纤激光器 超快光学 高阶模式 模式选择耦合器 声致光纤光栅 fiber lasers ultrafast optics high-order mode (HOM) mode selective coupler acoustically-induced fiber grating 
中国激光
2019, 46(5): 0508010
Author Affiliations
Abstract
Key Laboratory of Specialty Fiber Optics and Optical Access Networks, Joint International Research Laboratory of Specialty Fiber Optics and Advanced Communication, Shanghai Institute for Advanced Communication and Data Science, Shanghai University, Shanghai 200444, China
We experimentally demonstrate two kinds of all few-mode fiber (FMF) ring lasers with high-order mode (HOM) oscillation in the laser cavity. One kind is a switchable-wavelength all-FMF HOM laser with an output of tunable optical vortex beams (OVBs); the other is a Q-switched all-FMF HOM laser with an output of pulsed cylindrical vector beams (CVBs). The lasers are composed of all-FMF components and few-mode erbium-doped fiber. A Sagnac interferometer made of a 3 dB FMF coupler functions as the wavelength selector, and switchable multiwavelength tunable OVBs are experimentally realized. Carbon nanotube-based saturable absorbers and the nonlinear polarization rotation technique are used to achieve Q-switched CVB lasers. This is the first report, to our knowledge, on the generation of switchable-wavelength and Q-switched HOM beams in all-FMF laser cavities.
Photonics Research
2019, 7(1): 01000042

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