1 安徽工程大学电气工程学院，安徽 芜湖 241000
2 高端装备先进感知与智能控制教育部重点实验室，安徽 芜湖 241000
3 芜湖市固高自动化技术有限公司，安徽 芜湖 241000
针对视觉同步定位与建图算法在遮挡情况下易受到干扰而导致定位误差较大且闭环检测精度较低等问题，提出一种融合混合注意力实例分割的视觉同步定位与建图算法。该算法能够动态调整被遮挡物识别权重，在出现遮挡情况时提升对被遮挡物的特征提取与识别能力。同时采用概率去误匹配算法去除错误匹配点对，增加位姿求解及关键帧选取精度，从而更好地修正机器人位姿、提高系统构图的准确率。通过KITTI公开数据集和真实场景对所提算法进行测试，结果表明，所提算法在闭环准确率上与ORB-SLAM2算法相比约提高10.7%，平移误差约减小27.6%，体现了良好的构图能力。
遥感 同步定位与地图构建 注意力机制 实例分割 目标识别 闭环检测 激光与光电子学进展
2023, 60(10): 1028008
Author Affiliations
Abstract
1 State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
2 e-mail: xfchen@sjtu.edu.cn
Future quantum information networks operated on telecom channels require qubit transfer between different wavelengths while preserving quantum coherence and entanglement. Qubit transfer is a nonlinear optical process, but currently the types of atoms used for quantum information processing and storage are limited by the narrow bandwidth of upconversion available. Here we present the first experimental demonstration of broadband and high-efficiency quasi-phase matching second-harmonic generation (SHG) in a chip-scale periodically poled lithium niobate thin film. We achieve a large bandwidth of up to 2 THz for SHG by satisfying quasi-phase matching and group-velocity matching simultaneously. Furthermore, by changing the film thickness, the central wavelength of the quasi-phase matching SHG bandwidth can be modulated from 2.70 μm to 1.44 μm. The reconfigurable quasi-phase matching lithium niobate thin film provides a significant on-chip integrated platform for photonics and quantum optics.
Lithium niobate Thin film devices and applications Harmonic generation and mixing Nonlinear optics, integrated optics Photonics Research
2018, 6(10): 10000954
利用级联的线性电光效应对光进行控制是一种非常有效而且常用的控制光的手段。对于周期性畴反转铌酸锂(PPLN)一维光子晶体，在平行于光轴方向施加电场可周期性改变折射率大小，形成电光光子晶体结构；在垂直于光轴方向施加电场不仅可以改变折射率椭球大小，同时可以周期性改变折射率椭球主轴方向。综述了部分已报道的基于周期性的级联电光效应的应用，介绍了其在可调的手性器件、全光逻辑门、基于快慢光的时间隐身和非线性光学等方面的应用，展望了级联电光效应在未来集成光子芯片中的潜在应用。
非线性光学 级联电光光子晶体 电光效应 铌酸锂 激光与光电子学进展
2017, 54(6): 060001
Author Affiliations
Abstract
A switchable multiwavelength laser with a continuously tunable spacing is proposed and illustrated based on cascaded interactions of the second harmonic and difference-frequency generations in an aperiodically poled MgO-doped lithium niobate (MgO:APPLN) waveguide. The wavelengths and wavelength spacings of the four outputs are continuously varied and controlled by changing the two input pump wavelengths and spacings within a 3-nm flattop bandwidth of MgO:APPLN. In addition, the switchable states of the four outputs can be selected by inputting proper powers of the two pumps. The number of output wavelengths can also be increased by choosing the proper APPLN structure, the total length of MgO:APPLN, and higher powers of input pump lights.
130.3730 Lithium niobate 130.7405 Wavelength conversion devices 190.0190 Nonlinear optics Chinese Optics Letters
2013, 11(7): 071301
Author Affiliations
Abstract
We propose AND, NOR, and XNOR logic gates realized simultaneously for 40-Gb/s networks, in which the realization of NOR and XNOR logic gates using only MgO-doped periodically poled lithium niobate (MgO: PPLN) is reported. In our configuration, we exploit broadband quasi-phase matching (QPM) cascaded second harmonic and difference-frequency generation (cSHG/DFG), cascaded sum-frequency and difference-frequency generation (cSFG/DFG) in one MgO:PPLN, and the narrow band QPM sum-frequency generation (SFG) in another MgO:PPLN. The performance, including the quality-factor (Q-factor) and extinction ratio (ER), of the proposed multifunctional logic device is also simulated.
190.0190 Nonlinear optics 200.3760 Logic-based optical processing 130.3730 Lithium niobate Chinese Optics Letters
2013, 11(6): 061901
