共查询到19条相似文献，搜索用时 234 毫秒
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本系统由Nd:YAG二、三倍频激光泵浦有机染料,在可见区获得调谐激光输出,继而再利用喇曼移频技术扩展波段,如图所示。为了使Nd:YAG的输出同时具有高的功率密度和良好的光束质量,以便有效的产生各次谐波,采用衍射限输出的虚共焦非稳腔作为本振级,只需加一级放大,即达到基频800mj,二倍频350mj(最大450mj),三倍频150mj(最大190mj)的输出。整个系统简单,尺寸缩小,稳定性、可靠性增加。对于高重复率工作的非稳腔激光器,首先要合理选取腔长、输出耦合度、激光晶体棒直径、腔镜曲率半径等参数,还必须考虑工作物质的热效应,这对保证高质量的输出光束和稳定性是极为重要的。二倍晶体采用KD＊P(Ⅱ型)和β-BaB_2O_4(Ⅰ型)。KD＊P的抗激光损伤阈值高,光学质量好;β-BaB_2O_4是一种新型的非线性晶体,其非线性系数高,不潮解,在相位匹配 相似文献
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在实验室条件下,采用单程后向超荧光实验结构,利用波长为980nm的半导体激光器以光纤端对端方式直接抽运自制的掺Er3 碲酸盐短光纤.成功获得了宽带宽的超荧光.3dB带宽为60nm.中心波长为1545nm,所需光纤长度仅为6.5cm.同时,基于单程后向结构,超荧光的平均波长具有不依赖泵浦功率的稳定性,我们对光纤的长度进行了优化,对超荧光的谱宽特性及其随光纤长度变化的特性作了实验分析. 相似文献
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建立快速成型中的激光功率基础模型;利用热像仪采用新方法对树脂砂激光扫描的表面温度场进行测定和研究.并对激光功率基础模型及测温结果进行互相验证,该模型用于估算激光扫描功率参数及建立快速成型过程的数值计算模型. 相似文献
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激光二极管泵浦的内腔倍频全固态绿光激光器发展迅速,已经在通讯、医疗、激光显示和科学研究等领域得到了较为广泛地应用。研究高效率、高功率、高光束质量和/或高稳定性的全固态绿光激光器仍是当前研究的主要内容。以内腔倍频的方式产生绿光激光,对于平衡这几个方面的激光性能有较大优势。通过分析总结LD端面泵浦内腔倍频绿光激光器的研究历史可以看出,人们在研究绿光激光器的过程中始终以突破其中某一项性能指标或者平衡部分指标来优化性能为目标。对世界范围内的相关研究进行对比,标定目前所达到的研究水平,对于即将开展相关研究的科研工作者是一份有益的参考。目前来看,LD端面泵浦内腔倍频绿光激光器某些单方面的性能指标已经达到相当高的水平,并且很多是国内的研究者率先达到的。目前研究的重点应该是如何采取更好的方法使得激光器各方面突出的性能指标集于一体。 相似文献
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利用激光器无源谐振腔理论,结合矩阵光学变换分析法则,推导得出固体激光器双棒串接腔的等价参数表达式。依照理论设计实验,实验获得近似于单棒腔的双倍激光输出功率。 相似文献
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采用YAG固体激光对发动机气缸套进行热处理,研究了离焦量,激光功率、扫描速度厦表面处理对激光淬火硬度、淬硬深度及宽度的影响,试图找出激光热处理的最佳参数. 相似文献
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红光器件是通信领域各种光纤跳线、尾纤以及光纤线路维护等的重要捡测工具。而目前,红光光源的制备材料均为三五族材料的化合物半导体,如掺磷砷化镓等。为了降低成本研究制备出硅基红光光源是非常好的选择。本文中介绍了应用常规的等离子体增强化学气相淀积技术制备基于碳化硅的Fabry—Pemt结构全固态一维平面微腔。在488nm的激光激发下得到线宽为11nm,品质因子为59,峰位在646nm的发光谱线。与有源层的发光相比强度增强了2倍。为实现硅基光源在通信领域的应用奠定了基础。 相似文献
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太赫兹波及其产生方法的研究 总被引：2，自引：0，他引：2
阐述了太赫兹波的主要特征、太赫兹辐射产生的各种方法及其探测方法,重点介绍了产生THz辐射的光学方法和电子学方法。光学方法包括远红外光泵浦、利用超短激光脉冲产生THz辐射以及利用非线性频率变换过程产生THz辐射;电子学方法包括THz量子级连激光器、利用自由电子的THz辐射源、基于高能加速器的THz辐射源和电子学振荡器频率转换。 相似文献
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Yasmine El-Ashi Taha Landolsi Rached Dhaouadi 《Journal of The Franklin Institute》2011,348(7):1435-1455
In this paper, we study the accuracy of an optical vibration sensing system using Gaussian beam analysis. The proposed optical system uses a He-Ne laser source whose Gaussian beam impinges on a quad-cell photodetector array. The normalized optical power for each cell is obtained through numerical simulation based on the well-known Gaussian beam optics formulation, as the beam scans the plane of the photodetectors due to vibration. The system detection principle lies upon finding a relationship between the power distribution of the quad-cell and the position of the beam centroid, which allows us to identify the characteristics of the vibration applied, such as direction, frequency and strength. The aspects of practical implementation and experimental limitations on the power distribution accuracy are discussed and the discrepancies with the theoretical results are presented. 相似文献
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He Zhang Shaoyu Su Yan-Yong Zhao Junwei Lu 《Journal of The Franklin Institute》2019,356(16):9600-9626
Load frequency control of power systems is a very important approach to keep stability and security. Unfortunately, the traditional load frequency control is not effective because of the introduction of communication networks in multi-area power systems. In order to overcome this difficulty, sampling-based load frequency control for multi-area power systems is studied via an event-triggered detector. Unlike published works, an adaptive law for event-triggered scheme is given. Since multi-area power systems with event-triggered scheme are hybrid systems, there are a lot of challenges for analysing load frequency control problem. Some lemmas and a new Lyapunov function are developed to overcome these challenges. The obtained stability and stabilization criteria can provide a tradeoff to balance the required communication resources and the desired control performance. Numerical examples verify effectiveness of the obtained results. 相似文献
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本文测量了人的血清，血液，红血球溶液等多种样品的Ａｒ＋激光诱导的荧光光谱，指出在人体动脉的ＬＩＦ光谱中，红血球对荧光的吸收作用，在５００－７００ｎｍ波段，这种吸收是不均匀的，且在５４７，５８１ｎｍ处有最大的吸收，实验由计算机控制并进行采样和数据处理。 相似文献
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Using femtosecond laser to fabricate highly precise interior three-dimensional microstructures in polymeric flow chip 总被引：1，自引：0，他引：1
This paper reports using femtosecond laser marker to fabricate the three-dimensional interior microstructures in one closed flow channel of plastic substrate. Strip-like slots in the dimensions of 800 μm×400 μm×65 μm were ablated with pulse Ti:sapphire laser at 800 nm (pulse duration of ～120 fs with 1 kHz repetition rate) on acrylic slide. After ablation, defocused beams were used to finish the surface of microstructures. Having finally polished with sonication, the laser fabricated structures are highly precise with the arithmetic roughness of 1.5 and 4.5 nm. Fabricating such highly precise microstructures cannot be accomplished with nanosecond laser marking or other mechanical drilling methods. In addition, since laser ablation can directly engrave interior microstructures in one closed chip, glue smearing problems to damage molded microstructures possibly to occur during the chip sealing procedures can be avoided too. 相似文献
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设计了基于PPMgOLN晶体的高重频、高效率单谐振中红外参量振荡器。为了提高转化效率,自发研制了高功率,高重频,声光调Q的双端泵浦Nd:YVO4激光器作为泵浦光源,并对参量振荡腔进行了优化设计。在重复频率80 kHz,泵浦功率30 W时,获得了7 W的2.73μm中红外激光输出。光光转换效率为23.3%。采用温度调谐的方式,信号光输出光谱范围是1.67~1.75μm。对应的闲频光光谱范围是2.72~2.92μm。 相似文献