Author Affiliations
Abstract
1 College of Electronic Information Engineering, Shenzhen University, Shenzhen 518060, China
2 Key Laboratory of Advanced Optical Precision Manufacturing Technology of Guangdong Higher Education Institutes, Shenzhen Technology University, Shenzhen 518118, China
Swept source optical coherence tomography (SS-OCT) is a new noninvasive technique for assessing tissue. Although it has advantages, such as being label-free, noninvasive, and with high resolution, it also has drawbacks: there has been no in-depth research into identifying the driving of swept source. Based on preliminary research, we demonstrate a novel driving modulation method of a fiber Fabry–Perot tunable filter ranging phase adjustable as a tool for making bandwidth compensation of a swept laser source. This novel method is analyzed in detail; a swept laser source with a sweep rate of 100.5 kHz over a range of 152.25 nm and at a center wavelength of 1335.45 nm is demonstrated.
swept laser source optical design techniques ring lasers laser applications Chinese Optics Letters
2023, 21(1): 011407
Author Affiliations
Abstract
1 Key Laboratory of Advanced Optical Precision Manufacturing Technology of Guangdong Higher Education Institutes, Sino-German College of Intelligent Manufacturing, Shenzhen Technology University, Shenzhen 518118, China
2 College of Electronics and Information Engineering, Shenzhen University, Shenzhen 518060, China
A stable noise-like (NL) mode-locked Tm-doped fiber laser (TDFL) relying on a nonlinear optical loop mirror (NOLM) was experimentally presented. Different from the previous NL mode-locked TDFL with NOLM, the entire polarization-maintaining (PM) fiber construction was utilized in our laser cavity, which makes the oscillator have a better resistance to environmental perturbations. The robust TDFL can deliver stable bound-state NL pulses with a pulse envelope tunable from ～14.1 ns to ～23.6 ns and maximum pulse energy of ～40.3 nJ at a repetition rate of ～980.6 kHz. Meanwhile, the all-PM fiber laser shows good power stability (less than ～0.7%) and repeatability.
noise-like pulse all-polarization-maintaining fiber nonlinear loop mirror Tm-doped fiber laser Chinese Optics Letters
2021, 19(9): 091402
1 深圳大学信息工程学院, 广东 深圳 518060
2 深圳大学物理与光电工程学院深圳市激光工程重点实验室, 广东 深圳 518060
3 深圳技术大学, 广东 深圳 518118
4 山东大学晶体材料国家重点实验室和晶体材料研究所, 山东 济宁 250100
5 深圳市大族激光科技股份有限公司, 广东 深圳 518057
首次搭建了基于ZnWO4/Nd∶YAG的一阶斯托克斯拉曼激光器,并研究了其在不同重复频率与不同输出耦合镜下的输出特性。采用ZnWO4晶体作为拉曼晶体,二极管泵浦Nd∶YAG晶体产生基频光,实现了波长为1177.6 nm的一阶斯托克斯激光输出。当输出耦合镜的透过率为35%,泵浦功率为22.1 W,重复频率9 kHz时,在1177.6 nm处获得了最大平均输出功率,为886 mW,对应的最短脉宽为2.2 ns,峰值功率为43.9 kW。
激光器 固体激光器 拉曼 ZnWO4晶体
1 深圳大学电子与信息工程学院, 广东 深圳 518060
2 深圳大学深圳市激光工程重点实验室, 广东 深圳 518060
3 山东大学晶体材料国家重点实验室, 山东 济南 250100
4 深圳技术大学, 广东 深圳 518118
5 大族激光科技股份有限公司, 广东 深圳 518057
为研究ZnWO4晶体的二阶拉曼性质,搭建了基于ZnWO4晶体的二阶拉曼激光器,实现了重复频率为9 kHz的670 mW的1318.3 nm的二阶斯托克斯激光输出,对应的脉宽为3.294 ns,光光转换率为4.7%,峰值功率达到22.6 kW。实验结果表明,ZnWO4晶体具有良好的性能,能够实现二阶拉曼激光输出。
固体激光器 拉曼激光器 ZnWO4晶体
Author Affiliations
Abstract
College of Information Engineering, Shenzhen University, Shenzhen 518060
Multisensor image fusion could improve system performances such as detection, tracking, and identification greatly. In this paper, a long distance target detection approach is presented based on multisensor image features fusion. This method extracts two different features from visual and infrared (IR) image sequences respectively to detect regions of motion information content. Temporal change feature is extracted from the visual image sequence using temporal decomposition based on wavelet, which reflects the dynamical content variation at a pixel at any time. And correlation features between local regions are extracted from IR image sequence to distinguish regions with potential moving targets. All these features are merged into a multi-dimensional space and the support vector machine is trained to select regions that have the potential target at each pixel location. The method is robust and feasible to detect long distance targets in clutter background scene.
目标检测 图像融合 分类 100.5010 Pattern recognition 100.2960 Image analysis 100.2000 Digital image processing Chinese Optics Letters
2007, 5(7): 400
1 深圳大学信息工程学院电子工程系,广东,深圳,518060
2 西安电子科技大学电子工程学院,陕西,西安,710071
从理论上证明了小波变换法中存在的方块效应和光谱信息损失,同时证明了方块效应和光谱损失与小波变换的尺度密切相关,实验结果证明了理论分析的正确性.
图像融合 小波变换 遥感图像分析. image fusion wavelet transform remote sensing image analysis.
西安电子科技大学电子工程学院, 陕西,西安,710071
提出一种光点实时检测与跟踪的方法,在检测方法中,根据图像的分割信息和不同方向的灰度变化信息,以区分反光点和实际光点.在实时跟踪方法中,自适应调整波门位置及大小,并采用Cardinal样条进行插值以提高光点坐标计算精度.实验表明,本文提出的方法可以有效地去除反光点,计算的精度可达1%像素.
分割 方向滤波 跟踪 插值. segmentation direction filtering tracking intrapolation.
