1 长春理工大学光电工程学院, 吉林 长春 130022
2 东莞市宇瞳光学科技股份有限公司研发技术中心, 广东 东莞 523841
针对小样本条件下深度学习缺陷检测算法识别率较低的问题,提出一种基于双通道生成对抗网络的数据增强方法。由全局鉴别层和局部鉴别层两通道组成生成对抗网络,其中局部鉴别器可以增加缺陷类型的置信度损失,实现对局部信息的增强。采用所提方法在镜片缺陷图像数据集上进行实验。实验结果表明,所提方法的最近邻留一指标、最大均值差异和Wasserstein距离分别达到0.52、0.15和2.81;对于麻点、划痕、气泡和异物的缺陷类型图像,生成的图像质量优于条件生成对抗网络、Wasserstein距离生成对抗网络和马尔科夫判别器。双通道生成对抗网络生成的镜片图像有着多样性的全局信息和高质量的细节特征,可以有效增强镜片缺陷数据集。
激光与光电子学进展
2021, 58(20): 2015001
强激光与粒子束
2021, 33(7): 074001
Author Affiliations
Abstract
Key Laboratory of In-fiber Integrated Optics, Ministry of Education, Harbin Engineering University, Harbin 150001, China
We propose and demonstrate the cascaded multi-wavelength mode-locked erbium-doped fiber laser (EDFL) based on ultra-long-period gratings (ULPGs) for the first time, to the best of our knowledge. Study found that the ULPG can be used as both a mode-locker for pulse shaping and a comb filter for multi-wavelength generation simultaneously. Using the dual-function of ULPG, three-, four-, five-, six-, and seven-wavelength mode-locked pulses are obtained in EDFL, seven of which are the largest number of wavelengths up to now. For the four-wavelength soliton pulses, their pulse width is about 7.8 ps. The maximum average output power and slope efficiency of these pulses are 8.4 mW and 2.03%, respectively. Besides the conventional pulses, hybrid soliton pulses composed of a four-wavelength pulse and single soliton are also observed. Finally, the effect of cavity dispersion on the multi-wavelength mode-locked pulses is also discussed. Our findings indicate that apart from common sensing and filtering, the ULPG may also possess attractive nonlinear pulse-shaping property for ultrafast photonics application.
ultra-long-period grating fiber laser ultrafast laser multi-wavelength Chinese Optics Letters
2021, 19(7): 071405
针对光通信应用中一些光源输出波长和功率稳定性差的问题, 研制了一种基于垂直腔面发射(VCSEL)的光传输用多波长稳定光源。详细描述了稳定光源的结构和工作原理, 测试了其输出波长分别为660 nm、850 nm、1310 nm、1490 nm和1550 nm时的中心波长、输出功率以及输出功率的短时间和长时间稳定性。测试结果表明: 该稳定光源具有良好的性能, 适合作为光通信传输用的稳定光源。
垂直腔面发射 光传输 光通信 多波长 稳定光源 vertical cavity surface emission optical transmission optical communication multi-wavelength stable light source
辽宁石油化工大学机械工程学院, 辽宁 抚顺 113001
为了揭示核主泵屏蔽套用Hastelloy C-276薄板脉冲激光焊接的热力学行为, 借助ANSYS软件建立了三维有限元模型。实验测量了焊接温度历程和残余变形, 验证了所建立有限元模型的可靠性。基于验证的有限元模型, 采用改变焊接过程中的夹具拘束和随焊激冷等多场调控参数的方法, 进一步研究了夹具拘束距离、激冷位置以及激冷强度对Hastelloy C-276薄板焊接纵向残余应力和横向收缩变形的影响规律。结果表明, 温度历程和残余变形的模拟结果与实验结果吻合较好; 多场调控参数对焊接纵向残余应力和横向收缩变形的分布和大小有显著影响。鉴于焊接纵向残余应力和横向收缩变形是影响核主泵屏蔽套周长尺寸精度、整体稳定性以及超长使役的关键因素, 确定了既降低横向收缩变形又兼顾纵向残余应力尽量小的合理多场调控参数是夹具拘束距离为12 mm, 激冷位置为6 mm以及激冷强度为12 500 W/(m2·K)。
核主泵屏蔽套 激光焊接 残余应力 焊接变形 多场协同调控 nuclear reactor coolant pump can laser welding residual stress welding distortion multi-field coordinated control
哈尔滨工程大学 纤维集成光学教育部重点实验室, 黑龙江 哈尔滨 150001
多波长超快激光器在光通信、医学诊断和光学传感等各种应用中有着十分重要的应用前景。2009年以来, 石墨烯、拓扑绝缘体、过渡金属硫化物和黑磷等二维材料在超快光子学领域的发展非常快速。它们独特的非线性光学特性, 使之能够被用作快速响应、宽带运转的可饱和吸收体且能够容易地集成到激光器中。研究发现, 基于二维材料的非线性光学器件是研究激光器内非线性脉冲动力学演化的理想平台。在文中, 回顾了二维材料在多波长超快激光器中应用的最新进展。进而, 阐述了多波长的耗散孤子、矩形脉冲和亮暗孤子对等脉冲类型。最后, 提出了这类多波长超快激光器面临的挑战和应用前景。
二维材料 锁模激光器 非线性光学现象 多波长 孤子 two-dimensional materials mode-locked lasers nonlinear optical phenomenon multiwavelength soliton 红外与激光工程
2019, 48(1): 0103002
Author Affiliations
Abstract
Key Laboratory of In-Fiber Integrated Optics, Ministry of Education, Harbin Engineering University, Harbin 150001, China
Ultrafast lasers play an important role in a variety of applications ranging from optical communications to medical diagnostics and industrial materials processing. Graphene and other two-dimensional (2D) noncarbon materials, including topological insulators (TIs), transition metal dichalcogenides (TMDCs), phosphorene, bismuthene, and antimonene, have witnessed a very fast development of both fundamental and practical aspects in ultrafast photonics since 2009. Their unique nonlinear optical properties enable them to be used as excellent saturable absorbers (SAs) that have fast responses and broadband operation, and can be easily integrated into lasers. Here, we catalog and review recent progress in the exploitation of these 2D noncarbon materials in this emerging field. The fabrication techniques, nonlinear optical properties, and device integration strategies of 2D noncarbon materials are first introduced with a comprehensive view. Then, various mode-locked/Q-switched lasers (e.g., fiber, solid-state, disk, and waveguide lasers) based on 2D noncarbon materials are reviewed. In addition, versatile soliton pulses generated from the mode-locked fiber lasers based on 2D noncarbon materials are also summarized. Finally, future challenges and perspectives of 2D materials-based lasers are addressed.
140.3510 Lasers, fiber 140.4050 Mode-locked lasers 140.3540 Lasers, Q-switched Chinese Optics Letters
2018, 16(2): 020004
1 南昌工程学院 江西省精密驱动与控制重点实验室,江西 南昌 330099
2 江西机电职业技术学院,江西 南昌 330013
针对TFT-LCD点缺陷自动光学检测时, 缺陷与背景对比度较低难以用传统阈值分割算法处理的难题, 提出一种改进的Otsu算法, 并构建了TFT-LCD 点缺陷自动光学检测系统。首先, 通过Gabor滤波去除了纹理背景的影响。然后, 利用威布尔函数形态参数分段取值时, 其分布函数呈现的不同分布特性, 改进了传统Otsu阈值提取函数。最后, 进行了离线测试试验和在线测试试验。试验表明, 改进的Otsu算法在点缺陷与背景对比度较低的情况下分割效果优于传统Otsu算法。将该算法移植到TFT-LCD 点缺陷自动光学检测硬件平台上进行在线测试, 正确检测率可达到94%, 单个样本最短检测时间可缩短至150 ms。降低了TFT-LCD人工检测点缺陷的工作量和劳动强度。
点缺陷检测 改进的Otsu算法 自动光学检测系统 spot-type defect detection TFT-LCD TFT-LCD improved Otsu algorithm automatic optical detection system
哈尔滨工程大学纤维集成光学教育部重点实验室, 黑龙江 哈尔滨 150001
报道了一种基于石墨烯三元复合材料(石墨烯/二氧化锡/聚苯胺薄膜)的可切换双波长孤子光纤激光器。该石墨烯复合材料由液相超声法制备而成, 将其制成聚合物薄膜并转移到激光器腔内。该石墨烯器件不仅可以作为一种饱和吸收体来进行锁模, 而且具有较强的三阶非线性光学效应, 在激光器中, 它可以构成一种滤波器来产生双波长脉冲。利用该双功能器件实现了光纤激光器的双波长孤子运转, 最小脉冲宽度为1.25 ps, 基本重复频率为2.13 MHz, 相应的最高单脉冲能量为1.51 nJ, 峰值功率约为1.2 kW。
材料 石墨烯复合材料 被动锁模 孤子 多波长
