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摘要

通过氢化物气相外延(HVPE)方式在蓝宝石衬底上获得了GaN微米碟,其几何形态为规则的正六边形且表面平整,直径约为27 μm,高度为15 μm。光致发光(PL)实验结果表明,微米碟垂直方向和水平方向的光学谐振模式存在差异,其中水平方向支持回音壁模式(WGM)振荡。在室温条件下采用高能脉冲激光照射微米碟,当激励光功率超过7.8 μW时,PL光谱在波长374 nm附近获得多模式激光信号,其中WGM激光占优势,品质因子可达3742。最后采用COMSOL仿真软件对谐振腔进行光场模拟,并分析了其光学模式特性。

PDF全文HTML全文 光学学报 | 2020,40(12):1223001
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摘要

基于电磁感应透明原理理论研究了金刚石锡空位色心系统的光学双稳特性。研究表明,通过改变系统的参数,即探测场失谐量、耦合场失谐量和强度、合作参数等,可以显著改变系统的量子相干特性,从而可以有效调控该固态系统的光学双稳的阈值。另外,适当地调节耦合激光场的强度,可以实现光学双稳态和多稳态的相互转化。

PDF全文HTML全文 光学学报 | 2020,40(12):1219001
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针对机械微弯长周期光纤光栅的基模HE11到高阶纤芯矢量模式(TE01、TM01和HE21)的耦合特性,分析了阶跃型和反抛物线型两种少模光纤结构下机械微弯长周期光纤光栅的光栅周期、微弯幅度和耦合系数等参数对矢量模式耦合的影响。研究结果表明,耦合系数是模式耦合过程中的关键,通过施加压力改变光纤的微弯幅度可以有效调谐光栅矢量模式的耦合强度。基于反抛物线型光纤结构的机械微弯长周期光纤光栅可以特定波长激发特定的高阶矢量模式(TE01、TM01和HE21),并且由基模向高阶模式转换的谐振波长可调谐。该机械微弯长周期光纤光栅在矢量模式复用、轨道角动量的产生和复用领域有潜在的应用价值。

PDF全文HTML全文 光学学报 | 2020,40(12):1206003
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摘要

模式匹配分析法是计算亚波长光栅衍射效应的一种高效方法。对于亚波长层叠光栅,相邻的不同介质层边界处电磁场切向分量连续,每层中电磁场的各个波导模式对该层中电磁场的贡献与相邻层中电磁场切向分量的贡献相等,相邻层间模式匹配,故可将模式匹配分析法应用于亚波长层叠光栅中。通过具体实例比较了由模式匹配分析法与严格耦合波分析法计算得到的光栅衍射效率和电磁场强度分布,对比结果表明模式匹配分析法在分析亚波长层叠介质光栅方面相较于严格耦合波分析法更为高效,在收敛性以及计算速度方面有着独特的优势,且对于深刻理解层叠光栅对电磁波的衍射效应以及结合优化方法设计新型亚波长光栅、新型超表面方面具有重要意义。

PDF全文HTML全文 光学学报 | 2020,40(12):1205001
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摘要

针对压电快速倾斜镜的反作用力对有效光学元件的复杂动态耦合干扰问题,提出了基于多体系统的刚柔耦合和基于压电耦合理论的反作用力分析方法,对压电倾斜镜的反作用力进行了分析和补偿,并获取了中心柔性铰链的热点应力。理论和实验结果表明:压电耦合求解相比于多体系统的刚柔耦合方法更能准确地反映反作用力特性,实验测得反作用力的补偿比例可以达到90.14%,与数值计算的差异为3.96个百分点。所提的反作用力分析方法和动量补偿结构可为计算和消除倾斜镜的反作用力对光学系统的耦合干扰提供借鉴。

PDF全文HTML全文 中国激光 | 2020,47(06):0601007
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摘要

为解决脉冲信号对导频产生干扰进而导致马赫-曾德尔电光调制器(MZM)工作点无法稳定的问题,提出了一种导频自适应的偏压控制技术。采用数字控制系统生成频率可变的导频,由快速傅里叶变换分析反馈信号的谐波分量,可以将MZM锁定于传输曲线的最低偏置点。通过实时监测偏置电压输出,自主改变导频频率,避免脉冲信号对导频的影响,实现了高消光比的激光脉冲调制。结果表明,激光脉冲的重复频率与导频一次谐波频率接近时,脉冲信号会影响调制器工作点的稳定,该系统可以实现导频频率在0.45~2 kHz范围内的自适应变化,满足不同重复频率的激光脉冲调制需求。脉冲峰值为10 V、占空比为10 %时,调制光脉冲的消光比可达26 dB,相较于脉冲信号对导频产生干扰时,输出脉冲消光比提高了约24 dB。

PDF全文HTML全文 中国激光 | 2020,47(06):0601001
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摘要

以半导体光放大器为非线性元件的双环耦合全光缓存器(DLOB)为基础,实现了速率为2.5 Gb/s双波长数据的并行缓存。不同波长光信号合成后的功率随机波动,导致由半导体光放大器交叉相位调制产生的相位差随机波动。在考虑吸收损耗的情况下,对常用的半导体光放大器增益特性曲线进行了修正并与实测值拟合,得到了更为准确的增益特性曲线。在此基础上进行了理论分析,提出了通过调节控制光功率到最佳点以便减小相位差波动的方法。

PDF全文光学学报 | 2008,28(05):835-839
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摘要

提出一种基于中红外中空波导光纤的呼吸气体CO2测量系统,该系统使用中心波长为2.73 μm的分布式反馈(DFB)激光器结合1 m长的中空波导光纤,采用免标定波长调制光谱技术(CF-WMS)对呼吸气体CO2进行实时测量。采用CF-WMS技术得到的CO2气体浓度与配制所得的标准气体浓度之间的线性度为0.9999,在体积分数为0%~6%的范围内,测量结果与标准气体体积分数值之间的最大绝对误差为0.01%。由CF-WMS 技术反演的CO2体积分数精度为1.01×10 -5,在最佳积分时间26.00 s时,CO2气体的探测极限为1.3×10 -6。基于CF-WMS技术与传统的标定式波长调制技术(WMS)测量CO2气体体积分数的精度和灵敏度,并将两者进行比较,结果发现CF-WMS技术相对于WMS技术,测量精度提高了一倍,CF-WMS技术测量灵敏度为WMS技术测量灵敏度的1.4倍。对呼吸气体CO2实时测量时,采用CF-WMS技术测量的背景CO2体积分数基本稳定在3.8×10 -4左右,呼吸末CO2体积分数稳定在5.7%附近。

PDF全文HTML全文 光学学报 | 2020,40(11):1130001
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摘要

提出一种高光谱成像激光雷达系统的光学结构设计,并对系统的光学辐射定标方法进行研究。利用单色仪对出射光的精细扫描,确定高光谱成像雷达每个探测通道的带宽和中心波长。根据高光谱成像激光雷达方程,在实验室定标过程中,不考虑大气对定标的影响,得到系统每一个通道的定标系数。系统定标过程中合成不确定度为0.87%,扩展不确定度(k=2)为1.73%。最后对超连续谱高重复频率激光器出射的脉冲能量进行监测,使该高光谱激光雷达在机载飞行过程中,依据探测器输出的回波信号强度信息,能够实时得到地物的反射光谱信息,进而实现高精度地形获取和地表超精细分类。

PDF全文HTML全文 光学学报 | 2020,40(11):1128001
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摘要

提出了一种利用石墨烯基光学生物传感器对特异性生物小分子实现高灵敏检测的方法,采用易于修饰的磁性纳米颗粒作为生物探针载体,通过磁场控制实现磁性颗粒在石墨烯表面的吸附,优化了石墨烯表面复杂的改性过程。利用搭建的基于功能化修饰磁性纳米颗粒的石墨烯基光学生物传感器,实现了0.01 ng·mL -1的赭曲毒素A的检测,在0.01~5 ng·mL -1微小浓度范围内具有良好的响应,且表现出较好的特异性。该方法扩展了石墨烯基的光学生物传感器的应用范围,简化了生物分子的传感过程,提高了光学生物传感器的灵敏度。

PDF全文HTML全文 光学学报 | 2020,40(11):1117001
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摘要

针对水体小角度范围内后向散射强度测量难的问题,基于沙氏成像原理设计了水体沙氏激光雷达系统。介绍了水体沙氏激光雷达系统的设计、模拟及搭建,并对去离子水、自来水及河水三种水体进行水槽实验。详细介绍了多测量介质条件下的距离校正方法。将后向散射的光束宽度和强度变化情况与分光光度计测量数据进行比较,发现激光光束的宽度及强度变化表征光束衰减情况,同时可表征不同水体的后向散射强弱规律。分光光度计数据与水体沙氏激光雷达数据结果具有较好的一致性。

PDF全文HTML全文 光学学报 | 2020,40(11):1101004
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摘要

太赫兹量子级联激光器(THz-QCL)是用于实现自混合干涉的半导体激光器。利用自混合干涉效应,实验测量了THz-QCL频谱、线宽增强因子以及反馈光耦合系数。搭建了THz-QCL自混合干涉光路,基于THz-QCL驱动电压,获得了具有高信噪比的自混合干涉信号及其随反馈光光程变化的曲线。通过对自混合干涉信号进行解析,准确获得了THz-QCL在不同工作电流和温度下的激射频谱,频谱的分辨率反比于反馈光光程的变化。基于自混合干涉信号,分析得到了THz-QCL的线宽增强因子以及反馈光耦合系数。所实现的自混合干涉测量技术有望发展为物质的太赫兹频谱识别和测量技术。

PDF全文HTML全文 光学学报 | 2020,40(11):1114003
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摘要

加速稳健特征算法在多模核磁共振成像(MRI)肿瘤图像配准中,存在特征点偏少且配准精度低等问题。使用Harris角点检测法对参考图像、浮动图像的特征点进行提取和检测,接着使用圆形64维向量法生成特征描述符并进行欧氏距离匹配,来增强特征点的提取。通过设置配准图像初始化参数,确保粒子在最优值附近搜索,利用互信息作为粒子群优化算法的测度函数,增强目标函数全局最优解,通过引入平均最值,防止算法陷入早熟现象。仿真结果表明,与现有的算法相比,所提优化算法可以使多模MRI图像特征点增多且精度更高。

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摘要

采用数字微镜器件(DMD)无掩模光刻技术,以飞秒激光为光源,结合大面积拼接的方法快速制备了具有较高分辨率和毫米尺寸的大面积微纳结构。提出以单子场投影线扫描的方式进一步改善由于光场能量分布不均匀引起的结构边缘粗糙的问题,极大地降低了线条的边缘粗糙度,有效地控制了结构的精度。本研究以半导体领域常用的正性光刻胶为主要研究对象,实现了面积为7.4 mm 2的1 μm等间距线阵列和面积为38.7 mm 2的10 μm等间距线阵列结构的快速制备。本研究为大面积微纳结构制备提供了一种新方法,所制备结构可应用于气液流动、药物输运及晶体生长等领域。

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摘要

人类社会信息技术的快速发展不仅使得信息传递更加快捷,同时也对信息数据的存储产生了巨大的需求。如何对呈指数化增加的数据进行高速可靠、低能耗、低成本的长期存储已成为信息社会继续发展亟需解决的难题。为此,介绍了以玻璃为存储介质的光存储技术的发展现状,总结了玻璃介质光存储的应用方案,并对以玻璃作为存储介质的光存储技术未来发展趋势进行了展望。

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摘要

荧光显微镜因具有对样品损伤小、可进行特异性标记、适用于活体成像等优点,一直是生物医学研究中的主要手段。但光学系统自身缺陷、生物样品光学性质的不均匀性以及样品与显微镜浸润介质界面折射率的变化等导致了像差的产生,降低了成像的对比度和分辨率。自适应光学(AO)技术通过使用主动光学元件,如可变形镜、空间光调制器等,对畸变的波前(像差)进行校正,消除动态波前误差,恢复衍射受限性能。近年来,众多学者将AO系统与荧光显微镜相结合,以修正由样品不均匀性引起的像差,进而改善成像质量。介绍了AO技术的基本原理,综述了近年来AO技术在荧光显微镜成像中的应用,并对其未来发展趋势进行了展望。

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摘要

随着深度学习的不断发展与广泛运用,基于深度学习的目标检测算法已成为新的主流。为了进一步提高卷积神经网络YOLO v3(You only look once v3)的检测精度,在原算法的网络结构上添加卷积层模块对样本进行目标背景分类,并粗略调整特征图上的锚框大小。该模块输出目标背景概率后,过滤掉背景概率值低于设定阈值的样本,从而解决原算法中存在的正负样本比例失衡的问题。使用调整过的锚框替代原算法中直接由聚类生成固定大小的锚框,该过程为边界框的预测提供更优的初始值。在VOC数据集上的实验结果表明,相较于原算法,改进的YOLO v3具有更高的检测精度。

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摘要

无参考图像质量评价是近年来的研究热点,目前常用的评价算法都是从灰度空间提取特征。为了增加颜色通道信息对图像质量的反馈,分别提取了RGB(Red,Green,Blue )、LAB(Luminosity,A,B)、HSV(Hue,Saturation,Value)颜色空间中各通道下的亮度去均值对比度归一化(MSCN)系数,并用非对称广义高斯分布模型(AGGD)拟合。对拟合得到的MSCN系数统计特征,用梯度提升回归算法训练,得到无参考图像质量评价模型,并将各颜色通道训练模型和灰度空间训练模型的预测分数与主观评分进行比较。结果表明,相比灰度空间,部分颜色通道下的无参考图像质量评价模型的单调性、主客观一致性、稳定性都有一定提升,用RGB_B通道下提取的特征训练的模型性能最好,Pearson相关系数从0.63提升到0.70。

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摘要

提出了一种基于多尺度特征融合的细粒度图像分类方法。通过运用特征金字塔结构对不同层次的特征进行尺度变换,再进行信息融合;之后筛选其中包含细节特征最多的前三个区域图,将其与图像的全局特征共同作用以判断图片所属的子类类别。在公开的细粒度数据集CUB-200-2011、Stanford Dogs上进行了实验,得到的分类精度分别为85.7%和83.5%。实验结果表明该方法对于精细化物体分类具有一定的优越性。

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光声层析成像(PAT)作为一种新兴的成像技术,以独特的免标记、高分辨率、高对比度的多尺度成像能力,在生物医学成像中备受关注,正迅速向临床试验转化。得益于超声探测技术和激光技术的快速发展,PAT系统正逐步实现实时、大视场、高分辨率、高穿透深度的组织结构和功能成像。主要综述了环形阵列式PAT系统在生物医学成像中的研究进展及其在预临床和临床实践中面对的问题。

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Accurate placement of pedicle screw (PS) is crucial in spinal surgery. Developing new real-time intra-operative monitoring and navigation methods is an important direction of clinical application research. In this paper, we studied the spectrum along the fixation trajectory of PS in frequency domain to tackle the accuracy problem. Fresh porcine vertebrae, bovine vertebrae and ovine vertebrae were measured with the near-infrared spectrum (NIR) device to obtain the reflected spectrum from the vertebrae. Along the fixation trajectory of PS, average energy from different groups was calculated and used for identifying different tissues and compared to achieve the optimal recognition factor. Compared with the time domain approach, the frequency domain method could divide the spectra measured at different tissue points into different groups more stably and accurately, which could serve as a new method to assist the PS insertion. The results gained from this study are significant to the development of hi-tech medical instruments with independent intellectual property rights.

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    A distinguishing characteristic of normal and cancer cells is the difference in their nuclear chromatin content and distribution. This difference can be revealed by the transmission spectra of nuclei stained with a pH-sensitive stain. Here, we used hematoxylin–eosin (HE) to stain hepatic carcinoma tissues and obtained spectral–spatial data from their nuclei using hyperspectral microscopy. The transmission spectra of the nuclei were then used to train a support vector machine (SVM) model for cell classification. Especially, we found that the chromatin distribution in cancer cells is more uniform, because of which the correlation coe±cients for the spectra at different points in their nuclei are higher. Consequently, we exploited this feature to improve the SVM model. The sensitivity and specificity for the identification of cancer cells could be increased to 99% and 98%, respectively. We also designed an image-processing method for the extraction of information from cell nuclei to automate the identification process.

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      Computer-assisted cervical screening is an effective method to save the doctors' workload and improve their work e±ciency. Usually, the correct classification of cervical cells depends on the nuclear segmentation effect and the extraction of nuclear features. However, the precise nucleus segmentation remains a huge challenge, especially for densely distributed nucleus. Moreover, previous cellular classification methods are mostly based on morphological features of nucleus size or color. Those individual features can make accurate classification for severe lesions, but not for mild lesions. In this paper, we propose an accurate instance segmentation algorithm and propose cognition-based features to identify cervical cancer cells. Different from previous individual nucleus features, we also propose population features and cognition-based features according to the Bethesda System (TBS) for reporting cervical cytology and the diagnostic experience of the cytologists. The results showed that the segmentation achieves better success in complex situations than that by traditional segmentation algorithms. Besides, the cell classification via cognition-based features also help us find out more about less severe lesions' nuclei than that based on conventional features of individual nucleus, meaning an improvement of classification accuracy for cervical screening.

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        Optical coherence tomography angiography (OCTA) has emerged as an advanced in vivo imaging modality, which is widely used for the clinic ophthalmology and neuroscience research in the rodent brain cortex among others. Based on the high numerical aperture (NA) probing lens and the motion-corrected algorithms, a high-resolution imaging technique called OCT microangiography is applied to resolve the small blood capillary vessels ranging from 5 μm to 10 μm in diameter. As OCT-based techniques are recently evolving further from the structural imaging of capillaries toward spatio-temporal dynamic imaging of blood flow in capillaries, here we present a review on the latest techniques for the dynamic flow imaging. Studies on capillary blood flow using these techniques will help us better understand the roles of capillary blood flow for normal functioning of the brain as well as how it malfunctions in diseases.

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          摘要

          Early detection of vulnerable plaques is the critical step in the prevention of acute coronary events. Morphology, composition, and mechanical property of a coronary artery have been demonstrated to be the key characteristics for the identification of vulnerable plaques. Several intravascular multimodal imaging technologies providing co-registered simultaneous images have been developed and applied in clinical studies to improve the characterization of atherosclerosis. In this paper, the authors review the present system and probe designs of representative intravascular multimodal techniques. In addition, the scientific innovations, potential limitations, and future directions of these technologies are also discussed.

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            摘要

            This paper attempts to estimate diagnostically relevant measure, i.e., Arteriovenous Ratio with an improved retinal vessel classification using feature ranking strategies and multiple classifiers decision-combination scheme. The features exploited for retinal vessel characterization are based on statistical measures of histogram, different filter responses of images and local gradient information. The feature selection process is based on two feature ranking approaches (Pearson Correlation Coe±cient technique and Relief-F method) to rank the features followed by use of maximum classification accuracy of three supervised classifiers (k-Nearest Neighbor, Support Vector Machine and Naive Bayes) as a threshold for feature subset selection. Retinal vessels are labeled using the selected feature subset and proposed hybrid classification scheme, i.e., decision fusion of multiple classifiers. The comparative analysis shows an increase in vessel classification accuracy as well as Arteriovenous Ratio calculation performance. The system is tested on three databases, a local dataset of 44 images and two publically available databases, INSPIRE-AVR containing 40 images and VICAVR containing 58 images. The local database also contains images with pathologically diseased structures. The performance of the proposed system is assessed by comparing the experimental results with the gold standard estimations as well as with the results of previous methodologies. Overall, an accuracy of 90.45%, 93.90% and 87.82% is achieved in retinal blood vessel separation with 0.0565, 0.0650 and 0.0849 mean error in Arteriovenous Ratio calculation for Local, INSPIRE-AVR and VICAVR dataset, respectively.

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              摘要

              We introduce a method based on Gaussian mixture model (GMM) clustering and level-set to automatically detect intraretina fluid on diabetic retinopathy (DR) from spectral domain optical coherence tomography (SD-OCT) images in this paper. First, each B-scan is segmented using GMM clustering. The original clustering results are refined using location and thickness information. Then, the spatial information among every consecutive five B-scans is used to search potential fluid. Finally, the improved level-set method is used to obtain the accurate boundaries. The high sensitivity and accuracy demonstrated here show its potential for detection of fluid.

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                摘要

                Chemical imaging (CI) possesses a strong ability of pharmaceutical analysis. Its great strength relies on the integration of traditional spectroscopy (one dimension) and imaging technique (two dimensions) to generate three-dimensional data hypercubes. Data pre-processing or processing methods are proposed to analyze vast data matrixes and thereby realizing different research objectives. In this review paper, various pharmaceutical applications of quality control over the past few years are summed up in two groups of final product test and industrial utilization. The scope of "quality control" here includes traditional analytical use, process understanding and manufactural control. Finally, two major challenges about undesirable sample geometry and lengthy acquisition time are discussed for prospective commercial or industrial application.

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                  摘要

                  The concept of region of sensitivity is central to the field of diffuse optics and is closely related to the Jacobian matrix used to solve the inverse problem in imaging. It is well known that, in diffuse reflectance, the region of sensitivity associated with a given source–detector pair is shaped as a banana, and features maximal sensitivity to the portions of the sample that are closest to the source and the detector. We have recently introduced a dual-slope (DS) method based on a special arrangement of two sources and two detectors, which results in deeper and more localized regions of sensitivity, resembling the shapes of different kinds of nuts. Here, we report the regions of sensitivity associated with a variety of source–detector arrangements for DS measurements of intensity and phase with frequency-domain spectroscopy (modulation frequency: 140MHz) in a medium with absorption and reduced scattering coe±cients of 0.1 and 12 cm-1, respectively. The main result is that the depth of maximum sensitivity, considering only cases that use sourcedetector separations of 25 and 35 mm, progressively increases as we consider single-distance intensity (2.0 mm), DS intensity (4.6 mm), single-distance phase (7.5 mm), and DS phase (10.9 mm). These results indicate the importance of DS measurements, and even more so of phase measurements, when it is desirable to selectively probe deeper portions of a sample with diffuse optics. This is certainly the case in non-invasive optical studies of brain, muscle, and breast tissue, which are located underneath the superficial tissue at variable depths.

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                    摘要

                    Chern number is one of the most important criteria by which the existence of a topological photonic state among various photonic crystals can be judged; however, few reports have presented a universal numerical calculation method to directly calculate the Chern numbers of different topological photonic crystals and have denoted the influence of different structural parameters. Herein, we demonstrate a direct and universal method based on the finite element method to calculate the Chern number of the typical topological photonic crystals by dividing the Brillouin zone into small zones, establishing new properties to obtain the discrete Chern number, and simultaneously drawing the Berry curvature of the first Brillouin zone. We also explore the manner in which the topological properties are influenced by the different structure types, air duty ratios, and rotating operations of the unit cells; meanwhile, we obtain large Chern numbers from – 2 to 4. Furthermore, we can tune the topological phase change via different rotation operations of triangular dielectric pillars. This study provides a highly efficient and simple method for calculating the Chern numbers and plays a major role in the prediction of novel topological photonic states.

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                      摘要

                      The field of topological photonic crystals has attracted growing interest since the inception of optical analog of quantum Hall effect proposed in 2008. Photonic band structures embraced topological phases of matter, have spawned a novel platform for studying topological phase transitions and designing topological optical devices. Here, we present a brief review of topological photonic crystals based on different material platforms, including all-dielectric systems, metallic materials, optical resonators, coupled waveguide systems, and other platforms. Furthermore, this review summarizes recent progress on topological photonic crystals, such as higherorder topological photonic crystals, non-Hermitian photonic crystals, and nonlinear photonic crystals. These studies indicate that topological photonic crystals as versatile platforms have enormous potential applications in maneuvering the flow of light.

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                        摘要

                        Since the lasers at fixed wavelengths are unable to meet the requirements of the development of modern science and technology, nonlinear optics is significant for overcoming the obstacle. Investigation on frequency conversion in ferroelectric nonlinear photonic crystals with different superlattices has been being one of the popular research directions in this field. In this paper, some mature fabrication methods of nonlinear photonic crystals are concluded, for example, the electric poling method at room temperature and the femtosecond direct laser writing technique. Then the development of nonlinear photonic crystals with one-dimensional, two-dimensional and three-dimensional superlattices which are used in quasi-phase matching and nonlinear diffraction harmonic generation is introduced. In the meantime, several creative applications of nonlinear photonic crystals are summarized, showing the great value of them in an extensive practical area, such as communication, detection, imaging, and so on.

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                          摘要

                          Considerable research efforts have been devoted to the investigation of distributed feedback (DFB) organic lasing in photonic crystals in recent decades. It is still a big challenge to realize DFB lasing in complex photonic crystals. This review discusses the recent progress on the DFB organic laser based on one-, two-, and three-dimensional photonic crystals. The photophysics of gain materials and the fabrication of laser cavities are also introduced. At last, future development trends of the lasers are prospected.

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                            摘要

                            Novel optical properties in graded photonic super-crystals can be further explored if new types of graded photonic super-crystals are fabricated. In this paper, we report holographic fabrication of graded photonic super-crystal with eight graded lattice clusters surrounding the central non-gradient lattices through pixel-by-pixel phase engineering in a spatial light modulator. The prospect of applications of octagon graded photonic super-crystal in topological photonics is discussed through photonic band gap engineering and coupled ring resonators.

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                              摘要

                              Optical cavity polaritons, originated from strong coupling between the excitons in materials and photons in the confined cavities field, have recently emerged as their applications in the high-speed lowpower polaritons devices, low-threshold lasing and so on. However, the traditional exciton polaritons based on metal plasmonic structures or Fabry-Perot cavities suffer from the disadvantages of large intrinsic losses or hard to integrate and nanofabricate. This greatly limits the applications of exciton poalritons. Thus, here we implement a compact low-loss dielectric photonic – organic nanostructure by placing a 2-nm-thick PVA doped with TDBC film on top of a planar Si asymmetric nanogratings to reveal the exciton polaritons modes. We find a distinct anti-crossing dispersion behavior appears with a 117.16 meV Rabi splitting when varying the period of Si nanogratings. Polaritons dispersion and mode anti-crossing behaviors are also observed when considering the independence of the height of Si, width of Si nanowire B, and distance between the two Si nanowires in one period. This work offers an opportunity to realize low-loss novel polaritons applications.

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                                摘要

                                The idea of photonic crystals and photonic band gap was first introduced by both Yablonovitch [1] and John in 1987 [2]. Photonic crystals are man-made periodic optical media in which the dispersion of light is strongly modified due to the scattering of periodically arranged dielectric or metal inclusions in the unit cell. Photonic band gaps, a frequency range in which light cannot propagate, can form as a consequence of Bragg scattering or the resonance of the inclusions in the unit cell. The existence of band gaps means that photonic crystals can serve as low-loss distributed feedback mirrors and as such, they can confine light and can be used to realize high fidelity resonant cavities that can facilitate the observation of quantum electronics phenomena. The application of such ideas to realize strong coupling between photon and exciton is achieved using planar dielectric Si periodic structures [3]. When combined with a gain material, photonic crystals are obviously good platforms to realize lasing and indeed photonic crystal based lasers have attracted great interest in past three decades. The technical challenges and progress in distributed feedback organic lasers based on photonic crystals are discussed and reviewed by Fu and Zhai [4]. For practical applications, nonlinear photonic crystals with different superlattices has been successfully used in quasi-phase matching and nonlinear diffraction harmonic generation. This is reviewed by Li and Ma [5].

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                                  摘要

                                  Photonic crystals offer a platform for manipulating light at the mesoscopic scale owing to the unique photonic bandgap properties originating from spatially periodic dielectric distributions. Not only various integrated photonic devices have been realized based on photonic crystals, such as photonic crystal laser and logic devices, but also many physical effects including negative refractive and optical cloak have been realized in photonic crystals. Based on the photonic band structure, topological photonics has been an emerging research hotspot nowadays. Topological photonics provide two new modulation degrees of freedom, i.e., topological state degrees of freedom and energy valley degrees of freedom. It can be expected that topological photonics will not only boost the fundamental study of physical effects and phenomena, but also improve the research of high-performance photonic devices. Following the research trend in the field of photonics, the journal of Frontiers of Optoelectronics produces a special issue on Photonic Crystal and Topological Photonics in order to promote the research in the area of topological photonics and development of photonic devices based on topological features. In this special issue, Prof. Chan from The Hong Kong University of Science and Technology gives an in-depth comment on the development and research direction of photonic crystal and topological photonics. There are also three research articles and three review articles in this special issue. This special issue will improve the fundamental and application research of the field of photonic crystal and topological photonics.

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                                    摘要

                                    基于三磷酸腺苷(ATP)适配体与ATP分子作用后可以显著增强电化学发光信号的性能, 研究了一种用于ATP含量检测的电化学发光适配体(ECL-aptamer)传感器。通过电沉积方法获得纳米金电极。3′端标记联吡啶钌发光分子的探针DNA通过5′端修饰的巯基自组装到纳米金电极表面, 然后与5′端标记二茂铁分子的ATP核酸适配体互补杂交, 形成刚性线形的双链DNA, 由此构建的传感器产生较弱的电化学发光(ECL)信号。该传感器在ATP溶液中孵化后, 由于ATP分子与ATP适配体强的特异性结合, 使得适配体分子与探针DNA分子解离, 从电极表面脱落进入溶液, 此时电极表面的探针DNA在强电解质溶液中可以形成发卡型的茎环结构, 产生显著增强的ECL信号。ECL信号强度与ATP浓度的对数值呈线性关系, 线性范围为10.0~1.0×105 pmol/L, 相关系数r=0.995 9, 检测限为5.0 pmol/L。该传感器的灵敏度与检测范围高于目前已报道的结果, 显示出了ATP检测的应用潜力。

                                    PDF全文发光学报 | 2020,41(06):744
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                                    鉴于长余辉材料免实时激发特性可有效消除激发光源及复杂样品自体荧光的干扰, 近红外长余辉材料在生物成像领域受到了广泛关注。但其在荧光传感应用方面的报道相对较少, 尤其是利用长余辉纳米粒子来检测金属阳离子鲜有报道。本文采用水热法制备了Sn4+共掺的近红外长余辉纳米材料ZnGa2O4∶Cr3+,Sn4+ (ZGSC), 再以包硅处理得到在水溶液中分散性良好的荧光探针ZnGa2O4∶Cr3+,Sn4+@SiO2(ZGSC@SiO2)。基于Fe3+对长余辉材料ZGSC@SiO2的荧光猝灭效应, 构建了一种选择性好、无背景干扰的近红外长余辉荧光探针ZGSC@SiO2, 用于Fe3+的定量检测。采用时间分辨光谱可有效地消除背景干扰, 实现了高信噪比检测, 其线性范围为50~800 μmol/L, 检出限为25.12 μmol/L。选取了3种补铁口服液作为实际样品, 对其总铁含量以及Fe3+的含量进行检测, 并进行了加标实验。实验结果表明, 测定结果中总铁含量与标示值吻合; 3种样品中总铁含量的加标回收率为99.00%~99.79%, 相对标准偏差(RSD)为2.416%~3.808%; Fe3+含量的加标回收率为99.90%~102.69%, RSD为3.263%~4.296%, 满足测定要求。根据样品中总铁含量和Fe3+含量, 可计算得出Fe2+含量, 因此该荧光传感体系具有可同时检测Fe3+与Fe2+的优点, 可以用于补铁口服液中有效价态Fe2+的质量控制检测。

                                    PDF全文发光学报 | 2020,41(06):734
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                                    无创且实时检测微观环境的pH变化在医疗等领域具有重要的研究价值, 本文通过灵活简单的共沉淀方法制备了一种基于pH敏感分子异硫氰酸荧光素(FITC)的荧光pH纳米传感器, FITC的荧光强度随pH值增加发生明显变化, 当pH值从3变至9时, 荧光强度增大约38倍, 基于FITC荧光强度变化可实现对pH的灵敏检测, pKa值为 6.07。该荧光pH纳米传感器具有小粒径、高灵敏度、良好的可逆性和生物相容性, 在细胞等微环境pH检测方面将具有良好的应用前景。

                                    PDF全文发光学报 | 2020,41(06):729
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                                    摘要

                                    随着科学技术的发展与进步,人们对成像光学系统的要求也越来越高。传统球面以及非球面可供光学设计使用的自由度较少,且结构受限,难以实现越来越高的设计要求。自由曲面打破了旋转对称以及平移对称的几何约束,其面形更为灵活,需要使用更多的参数来进行面形描述,可以为光学设计带来更多的设计自由度,特别适用于校正非旋转对称系统的像差,同时可以减少系统中元件的数量,降低系统的体积与重量,实现传统光

                                    PDF全文 光学学报 | 2021,41(01):010801
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                                    可见光和红外图像是电力巡检机器人检测电力设备健康状态的重要方式,而图像配准可以结合两类图像的优势,为后续的状态监测提供更好的依据。针对因红外图像模糊导致的配准精度下降,本文提出基于显著性梯度的归一化互信息算法。在红外图像视觉显著性检测的基础上,强化显著性区域的边缘梯度,然后将显著性梯度信息和归一化互信息结合作为配准的测度函数。其次,为了提高图像配准算法的收敛性,提出一种适用于图

                                    PDF全文 光学学报 | 2020,40(16):161003
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                                    针对先进驾驶辅助系统对车辆前视景深信息的需求,本文在无监督学习的框架下提出了一种基于单目视觉的场景深度估计方法。为了降低不同尺寸前视目标对景深估计结果的影响,该方法采用金字塔结构对输入图像进行预处理;在训练过程中,将深度估计问题转化为图像重建问题,利用双目图像设计了新的损失函数代替真实深度标签,解决了真实场景深度数据难以获取的问题;将中间多尺度的视差图统一至原输入图像尺寸,改善

                                    PDF全文 光学学报 | 2020,40(17):171501
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                                    摘要

                                    环境温度的变化引起光学系统产生热离焦现象,导致系统像质不稳定。现有无热化方法在深紫外波段内,由于材料的限制,使光学系统的无热化过程和结果变得十分复杂。因此,本文提出了运用拆分系统设计和单层衍射光学元件相结合的方法实现深紫外光学系统的无热化设计。该方法首先通过消热差、消色差方程组求解结果对深紫外光学系统进行拆分再组合简化了无热化设计过程,然后通过在组合系统中加入单层衍射光学元件简

                                    PDF全文 光学学报 | 2020,40(17):172201
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                                    为了实现空间探测场景中对于探测光学系统灵敏度、探测时效性、孔径和总长等的需求,设计了一种大相对孔径大视场空间光学探测系统,依据探测器指标与目标特性计算并确定了系统设计参数,实现了对12.5等星的探测。系统采用非对称双高斯透镜组光学结构,工作于450nm~850nm波段,视场角2ω=20°,F数为1.05,入瞳口径150毫米。系统中一个透镜前表面采用XY多项式自由曲面进行设计,设计与分析结果表明,该系统弥散斑

                                    PDF全文 光学学报 | 2020,40(17):172202
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                                    卫星本体部件的闪光现象是卫星个体特征的体现,结合卫星运动特性以及镜反材质反射特性,从原理上研究了镜反部件指向确定方法,给出卫星本体反射率与镜反部件面积的确定方法。在此基础上,定量分析了卫星本体部件的闪光现象,提供一种多元模型用于描述卫星光学散射特性,并进行了实测数据验证。研究表明,多元法描述卫星光学散射特性较二元法更为全面,原理适用性更强,能够更具体的反应卫星个体独有的光学散射

                                    PDF全文 光学学报 | 2020,40(17):172901
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                                    数字均值滤波器在高精度测温系统中可以有效降低噪声,提高信噪比,但也会造成信号的失真,引入不确定度,而采集到的温度信号一般为离散时间序列信号,现有的滤波器评价方法很难量化这种信号带来的失真。本文为解决该问题,分析了温度缓变对象的温度变化特性,通过低噪声、高精度测量仪器采集被测物的典型温度信号序列,并由此构建数字均值滤波器的输入序列,从而得到该滤波器在当前输入信号模型下的不确定度,

                                    PDF全文 光学学报 | 2020,40(17):171201
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                                    针对复杂背景下船舶目标图像弱信号检测率低和可见光遥感相机的多光谱数据利用率低的问题,提出了一种面向蓝、绿、红和近红外四波段多光谱遥感图像船舶目标显著性检测算法。该算法利用四波段遥感图像中可见光图像的色彩信息较丰富、近红外图像具有对细节的描述能力较好的特点,首先将可见光蓝、绿、红三通道图像变换到CIELab色彩空间;然后将近红外图像进行非下采样轮廓波变换分解,对得到的高频分量进行非线性

                                    PDF全文 光学学报 | 2020,40(17):172801
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                                    面阵探测器作为多角度偏振成像仪的核心部件,用于实现多角度多光谱偏振辐射信息的光电转换。探测器装机之前需要对其光电性能进行全面的测量,为保证其应用性能,需对探测器进行精密控温,保证其工作在较低且稳定的温度以降低探测器的热噪声和暗电流。针对上述需求研制了一套高精度和高稳定度的科学级裸片探测器制冷系统。提出了一种基于低温循环机和薄膜电加热器相组合的探测器控温方法,减小测试光源及环境温

                                    PDF全文 光学学报 | 2020,40(17):170401
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                                    多普勒激光雷达在大气风场探测方面已经得到了广泛应用。光纤Mach-Zehnder干涉仪作为多普勒激光雷达的新型鉴频系统,具有体积小、轻便、稳定性高的优点。鉴于一般常用的单模光纤Mach-Zehnder干涉仪与望远镜接收系统的多模光纤直接耦合时能量耦合损耗严重,耦合效率低的缺点,提出采用多模光纤Mach-Zehnder干涉仪作为鉴频系统,提高耦合效率,实现能量及探测高度的提升。针对多模光纤Mach-Zehnder干涉仪可能产生

                                    PDF全文 光学学报 | 2020,40(17):170602
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                                    有限远零位补偿检验非球面装调环节多,影响着检验精度,因此提出前后零位补偿结合的无限远检验非球面光学系统,在待检镜球心前后各采用一个补偿透镜,使前后区间具有像差相关性。基于像差理论,对两片补偿透镜光学参数进行推导求解,分析初始参量与规化数据关系,再利用光学软件对计算结果进行缩放与优化,得到不同前零位补偿透镜放大率β2检验四种曲率半径凹抛物面镜的光学设计,给出检验达到的最大口径和相

                                    PDF全文 光学学报 | 2020,40(17):172203
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                                    采用自由曲面透镜作为分束器以生成具有给定能量比的离散光斑阵列。首先根据能量守恒,将入射光分为一系列与阵列光斑对应的子区域。对于每个子区域,采用变量可分离的光线映射法计算子区域与相应光斑之间的映射关系,最后采用最小二乘法构造遵循该映射关系的自由曲面。提供两个设计实例以检验自由曲面分束器的可行性:i)设计生成具有相同能量比例的高斯光斑阵列,ii)设计产生具有预设不均匀能量比例的矩形平顶

                                    PDF全文 光学学报 | 2020,40(17):172204
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                                    摘要 当目标发生旋转和尺度变化等的因素时,会导致跟踪算法出现目标丢失和精度大幅度下降等问题。因此解决目标在运动过程中出现的旋转以及尺度变化成为当前研究的热点。本文提出具有旋转特性的目标跟踪算法,该算法以Hamed等人提出的 BACF(Background-Aware Correlation Filters)为基准,保留BACF算法中的定位,将笛卡尔坐标系下的目标特征转换到极坐标系下,并采用傅里叶-梅林公式来计算目标旋转角度和尺度

                                    PDF全文 光学学报 | 2020,40(17):171502
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                                    传统离轴反射光学天线出瞳距较短,需要中继光学系统将出瞳成像于快反镜附近,这会导致后续光路和结构复杂化,且中继光学系统的后向散射光会对激光通信终端产生严重影响。针对上述缺陷,本文设计了长出瞳距离轴四反光学天线,通过将光学天线出瞳直接设计于快反镜上,省去了中继光学系统。首先,从同轴三反像差理论出发,推导了像差表达式和初始结构方程。然后,基于像差理论和出瞳位置要求,计算了离轴四反光学

                                    PDF全文 光学学报 | 2020,40(18):182201
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                                    太赫兹(THz)技术在诸多领域有着广阔的应用前景。THz探测器作为THz领域的核心器件仍面临着经济、实用和高效探测的挑战。我们设计实现了一种三维多孔石墨烯辅助胆甾相液晶胶囊测量高强度THz波的新型功率探测器。三维多孔石墨烯在0.5 - 1.5 THz范围内具有超过97%的高吸收率,利用温度超灵敏胆甾相液晶胶囊的热色特性,对稳态下太赫兹功率进行了可视化定量研究,THz探测强度高达2.77×〖10〗^2 mW/cm^2,最低探

                                    PDF全文 光学学报 | 2020,40(17):170402
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                                    光学载荷辐射定标结果的地基验证受地-气系统多因素综合影响且伴随着诸多不确定度,导致单场单次验证结果存在差异,且验证结果之间无法进行有效对比和综合分析,难以实现真正意义上的载荷辐射性能验证。本文综合考虑单场单次验证目标特性、大气环境等因素的影响,提出了一种以验证结果不确定度为权重的基于加权平均值综合定权方法,获取更接近真实值的关键比较参考值,实现单场单次验证结果的对比和综合分析。

                                    PDF全文 光学学报 | 2020,40(17):171202
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                                    针对清理空间非合作目标任务中如何获取目标的相对位置和姿态的难题,提出一种双目视觉位姿测量方法。首先,设计了基于双目视觉的位姿测量算法,利用弧支撑线段的方法快速检测目标表面的对接环,通过极线约束和光流法辅助跟踪的方法建立复杂场景下的对接环检测和筛选机制;利用两次遍历法快速标记连通区域,加入面积和曲率约束,提取目标表面特征较突出的规则标志点。利用三维重建后的对接环平面和标志点建立目

                                    PDF全文 光学学报 | 2020,40(17):171203
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                                    激光诱导荧光(LIF)是一种有效的海面溢油遥感探测技术。双向反射再辐射分布函数(BRRDF)可描述介质表面入射激光与出射荧光的量值关系,可为LIF技术探测海面溢油污染提供理论指导。针对目前人们尚未涉及海面溢油污染中水包油乳化液重要LIF探测参数的研究问题,本文基于蒙特卡罗方法建立了海面溢油水包油乳化液的光子传输模型。首先利用Mie散射理论计算不同乳化时间水包油乳化液的固有光学参数;其次针对激发波长

                                    PDF全文 光学学报 | 2020,40(17):170101
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                                    针对可见光与红外大口径薄膜衍射光学系统空间应用的可行性分析问题,本文提出了基于二维时域有限差分法的大口径衍射光学成像特性仿真建模与快速分析计算方法。首先充分考虑大口径衍射光学元件的亚波长微结构尺寸的电磁场调制特性,采用二维时域有限差分法,建立基于矢量衍射理论的亚波长特征尺寸衍射光学系统成像特性分析模型;然后通过矢量化编程和GPU加速运算,提出快速求解方法,有效解决了矢量计算所致的

                                    PDF全文 光学学报 | 2020,40(17):170502
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                                    提出了一种利用光流场原理测量物体面形的新技术。测量系统由投影仪、被测物体以及CCD摄像机组成。将光栅条纹以小角度投影到参考平面上,分别采集加入被测物体前后的两幅条纹图像。通过对测量系统的空间几何结构的分析,建立了以参考面为参照系的投影仪、摄像机、观测点的位移三者与物面高度的空间关系,而观测点的位移是利用Brox光流算法估计两帧图像间的光流分布得到。针对测量系统导致的测量结果与实际形状

                                    PDF全文 光学学报 | 2020,40(17):171204
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