【摘 要】
:
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 insulat
【机 构】
:
KeyLaboratoryofIn-FiberIntegratedOptics,MinistryofEducation,HarbinEngineeringUniversity,Harbin150001
【出 处】
:
ChineseOpticsLetters
论文部分内容阅读
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.
其他文献
Nonlinear-optical-loop-mirror-based wavelength conversion is studied in details. A set of two-phase-shifted Bragg gratings are introduced into the coverter, serving as a narrow band-pass filter to remove new frequencies generated by walk-off and to compen
运用微微秒光谱学中的激发与探测方法,测量了5K下GaAs样品的时间分辨吸收光潜。结果表明:激子被屏蔽的时间约600ps,从电子-空穴对等离子体到激子态的转变不是一个突变过程,在1ns之后出现一个来源于激子被散射的“透过”峰。
在扩展白光编码栅谱衍射干涉法的基础上,本文提出了用同轴计算机傅里叶全息图合成编码栅的新方法,使得谱衍射干涉法的干涉形式可随编码栅图案改变的特点成为现实可能,相应能容易地产生一般干涉形式之外的任何干扰图.编码谱函数由一定的几何图案所构成,本文还提出了几何光学近似方法,使得物面函数可近似用纯相位变化表示,这样将得到较易制作的两元型干涉计算机全息图,从而也避免了复杂的两维傅里叶变换计算.
A tunable surface-emitting integrated lighting system is constructed using a combination of inorganic light-emitting diodes (LEDs) and transparent organic LEDs (OLEDs). An RB two-color LED is used to supply red and blue light emission, and a green organic
复眼成像系统具有视场大、体积小、质量轻等优势,近年来得到国内外的广泛研究,是光学成像技术未来发展的方向之一。受限于较小的子孔径口径,现有大视场复眼系统得得分辨率较低,无法满足遥感、航空侦察等领域的需求。针对上述问题提出了双模式复眼成像系统,该系统不仅具备传统复眼的多孔径和大视场成像能力,同时可将所有子孔径指向同一视场,对采集的多幅子图像进行高分辨重建,大幅提升了成像分辨率。对该系统的原理和实现方法
罗彻斯特大学的研究人员研制了一项可降低用于高质量光学产品的透镜制造成本的方法,用激光器对这些产品进行测试。
运动图像目标检测指的是从序列图像中将变化的目标从背景中分离出来,高斯混合模型可以对视频序列图像的前景和背景进行分类,再利用背景减除实现运动目标的检测。提出一种基于改进高斯混合模型的优化背景建模方法,该方法首先利用3×3模板对序列图像帧中的像素进行类似卷积的均值计算,然后利用相邻均值的差提取均差因子自适应更新图像的均值。在此基础上,设计了自适应学习率和学习速率,利用改进高斯混合模型实现序列图像的背景
研究钠氩(Na-Ar)混合物电离后产生的原子发射光谱的时间分辨特性。氩763.5 nm光谱强度随时间演变出现2个峰,第1个峰的衰减时间为(33.3±2.3) ns,激发态钠通过碰撞传能[(时间常数为(15.2±0.8) ns]将氩激发到2p6能级,再由该能级的粒子快速辐射形成第1个峰;第2个峰由氩离子与电子复合产生,其衰减过程包括快过程[(0.24±0.03) μs]和慢过程[(3.98±1.03) μs]。利用电子浓度随时间的演变关系分析了复合过程对衰减时间的影响机理,获得了电子浓度、电子温度随时间的演