共查询到20条相似文献,搜索用时 500 毫秒
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光纤传输是常用的激光传输方式,随着光纤制备工艺的提升,大芯径、大数值孔径的传能光纤被广泛应用于多模激光传输。高效的激光耦合是光纤稳定传输的前提,为实现宽波段、高功率密度的激光耦合,根据混合模类高斯光束传输变换特性和耦合装置初始参数,结合像差分析,设计了一套大芯径四合一集束光纤与单芯光纤之间的非球面镜耦合装置,并通过机械装置装调实验得到了最高60.6%的光纤耦合效率。搭配自研激光共振电离飞行时间质谱仪,实现了钕同位素三色三步光电离路径对应激光饱和功率密度的测量,验证了装置满足复色激光共振激发电离特定同位素的光谱实验需求。 相似文献
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光纤的能量传输特性及应用 总被引:5,自引:0,他引:5
着重分析了影响光纤传输能量以及光纤传输中造成能量损耗的因素。这些因素主要包括光纤材料、构造、光纤的折射率分布、光纤的长度和芯径、光纤的数值孔径和热效应以及耦合等。同时 ,结合激光二极管点火的实例 ,分析探讨了其背景和应用价值。结论是 :为了尽可能减少能量损耗、提高光纤输出的激光功率和激光功率密度 ,应当选取合适的激光工作波长、较小的光纤长度、较小的芯径和较小的数值孔径 ,应采用渐变折射率分布光纤 ,应减少弯曲与耦合 相似文献
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采用Matlab和Comsol建立单模光纤内激光传输模型,对双包层内光纤折射率和纤芯结构对光能量分布的影响进行了理论研究。系统分析了光纤芯径与数值孔径、归一化频率和功率填充因子的关系,依据得到的结果进一步采用多模物理耦合仿真方法对不同类型的单模双包层光纤纤芯的能量分布进行仿真,探索了不同折射率分布情况对纤芯能量分布的影响。计算和仿真结果表明:凹面折射率分布光纤的光斑模场面积最大,单位面积的功率分布最低。针对大功率光纤激光器的应用需求设计了工作波长为1.064 m、纤芯直径为10 m、凹面直径为8 m、数值孔径为0.12的单模凹面折射率双包层光纤,为提高光纤泵浦效率、降低纤芯的能量密度提供了思路。 相似文献
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激光注入误差对多模光纤传能特性影响分析 总被引:2,自引:0,他引:2
采用ZEMAX软件对激光光纤注入系统进行了建模,仿真分析了激光注入光纤横向偏移、角度偏移对光纤传输激光能量特性的影响.结果表明,光纤输出激光能量分布与激光注入对准误差密切相关.注入误差引起光纤初始输入段激光峰值功率密度的剧烈波动,出现了一个激光峰值功率密度极大值,这个极大值是可以达到光纤截面内激光平均功率密度的数十倍;横向偏移激发大量斜光线产生,使光纤输出激光能量分布匀化;角度偏移仅影响光纤内子午光线与斜光线的传播方向,对光纤内激光能量分布的匀化作用较弱. 相似文献
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针对惯性约束聚变装置对激光集束辐照均匀性的需求,提出了一种基于涡旋光束的超快速角向匀滑方案,即利用螺旋相位板使2×2集束中的两子束由超高斯光束变换为涡旋光束,而其余两子束不变,进而通过对子束偏振态和中心波长的调控,使集束中的涡旋光束和超高斯光束在靶面两两相干叠加.相干叠加后的焦斑以皮秒量级为周期超快速旋转,从而在极短时间内快速抹平焦斑强度调制,改善靶面辐照均匀性.通过建立基于螺旋相位板的激光超快速角向集束匀滑方案的物理模型,分析了其角向匀滑特性,并与光谱角色散技术和径向匀滑技术进行了比较分析.结果表明,这一新型激光集束匀滑方案能实现对焦斑的超快速角向匀滑,且能在数皮秒时间内达到最佳辐照均匀性. 相似文献
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We propose a novel on-line beam diagnostic method based on single-shot beam splitting phase retrieval. The incident beam to be measured is diffracted into many replicas by a Dammann grating and then propagates through a weakly scattering phase plate with a known structure; the exiting beams propagate along their original direction and form an array of diffraction patterns on the detector plane. By applying the intensity of diffraction patterns into an iterative algorithm and calculating between the grating plane, weakly scattering plane, and detector plane, the complex field of the incident beam can be reconstructed rapidly; the feasibility of this method is verified experimentally with wavelengths of 1053 and 632.8 nm. 相似文献
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利用束流截止板热量计原理,测量了诊断中性束(DNB)注入托卡马克的束流功率及束流剖面分布。基于热量截止板上正交分布的13只K型热电偶探针测量出DNB引出束流,在加速极电源49 kV,6 A,100 ms的脉冲放电时,采样铜靶上的最高温升为14 ℃,从而计算出注入束流功率达到160 kW并得到束剖面分布。同时通过对热量截止板冷却循环水温升测量值在时间上的积分数值计算,也获得了注入束流总功率,为130 kW。分析了两种测量结果存在差异的原因,实验结果表明惯性束截止板热量计方法是测量粒子束流功率及剖面分布的有效手段。 相似文献
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The oblate spheroidal wavefunctions proposed by Rodríguez-Morales and Chávez-Cerda are shown to be possible representations of physical beams only when the angular function S(mn)(β,η) has odd n-m. This condition makes S(mn) odd in η, which ensures the convergence of integrals of physical quantities over a cross section of the beam. The odd n-m condition also makes S(mn)(β,η) zero in the focal plane z=0 outside the circle ρ=b, and thus allows for the physically necessary discontinuity in phase at z=0 on the ellipsoidal surfaces of otherwise constant phase. Only a subset of the oblate spheroidal functions can be exact representations of nonparaxial scalar beams. 相似文献
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在利用液晶空间光调制器(LCSLM)产生涡旋光束时,入射光的偏振方向对涡旋的产生有着明显的影响。从液晶空间光调制器的工作原理出发,研究了不同偏振方向的线偏振光在通过LCSLM的相位调制后,涡旋光束产生的变化。通过模拟仿真与实验结果的比较,发现随着线偏振光的偏振方向与液晶分子光轴夹角的增大,液晶空间光调制器的调制误差变大,所产生的涡旋光束的质量变差。当夹角大于4.725°时,涡旋光束的质量明显变差。而随着夹角继续增大,LCSLM对入射光的调制作用减弱,无法产生涡旋光束。 相似文献
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Based on the theory of the second intensity moment of nonparaxial scalar beam and the method of angular spectrum, the expressions for the far-field divergence angle, waist width and M2 factor of nonparaxial Hermite-sine-Gaussian (HSiG) beams are derived. Calculation and analysis show the dependence of the far-field divergence angle of nonparaxial HSiG beams on the parameter w0/λ, as well as on order m, And it with even and odd orders approach 73.898° and 63.435° as w0/λ → 0. With increasing order m and the parameter w0/λ, the waist width increase monotonously, which is same as paraxial case. But nonparaxial M2 factor is different from paraxial case, it cannot only less than 1, but also approach 0 as w0/λ → 0. 相似文献
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Scintillation evaluations for Laguerre-Gaussian (LG) beams for slant paths are made using Rytov approximation. On- and off-axis scintillation is formulated and calculated up to several tens of kilometers of slant distances for different zenith angles. Scintillation index variations against radial receiver point and different source sizes are also investigated. In all cases evaluated, it is found that LG beams with higher radial mode numbers result in less scintillation than Gaussian beam. Kolmogorov spectrum function is utilized in the scintillation calculations. 相似文献
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In this paper, we describe a wide-angle laser beam scanner and the rigorous result of the wide-angle laser beam scanner was obtained with the help of the vector refraction theory. Using the rigorous results, the distortion of the beam shape was discussed. The distortion of the beam shape is varying with the different relative angles of the double prisms. According to the conservation of the energy, the distribution of the laser intensity is changed too. 相似文献