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锥形透镜光纤聚焦特性研究 总被引:4,自引:2,他引:2
锥形透镜光纤(TLF)是实现光纤与平面光波光路(PLC)芯片高效耦合的核心元件。了解和掌握其聚焦特性是指导平面光波光路尾纤封装技术的关键。给出了表征锥形透镜光纤聚焦特性的两个参量出射光斑直径和远场发散角的理论分析模型,其误差小于1.14%;采用光束传播法数值模拟了锥形透镜光纤中的光波传输和模斑的演化,确定了锥形透镜光纤端面出射光斑的大小;优化锥形透镜光纤结构参量为:拉锥长度300μm,锥角0.733°,透镜曲率半径13.485μm;建立了基于数字摄像机的锥形透镜光纤出射光场测试系统,提出了物理光学反向推演法,计算出锥形透镜光纤聚焦光斑尺寸和远场发散角。理论与实验结果有着良好的一致:对于相同结构参量的锥形透镜光纤,实验反推法得到的出射光斑尺寸与理论值相比误差为3.15%,远场发散角误差为3.67%。 相似文献
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三种不同端面光纤列阵和半导体激光列阵耦合的(数值)模拟 总被引:2,自引:0,他引:2
半导体激光列阵的输出光束有较大的发散角和较强的不对称性,极大地限制了其在各领域中的应用。为了改善半导体激光列阵输出光束的质量,必须采用特殊的光学系统进行光束整形。一种简单有效的方法是利用光纤列阵实现光束由线性排列到圆形排列的转换。对三种特殊制备的光纤列阵和半导体激光列阵的耦合特性进行了数值模拟研究。结果显示,相对于球形端面光纤列阵和锥形端面光纤列阵,球顶锥形端面光纤列阵和半导体激光列阵有着更高的耦合效率(90%以上)。此外,利用球顶锥形端面光纤列阵还可以进一步压缩输出光束的发散角,从而获得更高质量的输出光束。 相似文献
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针对目前铜、金等金属材料加工的实际应用需求,开展了连续输出功率500 W的光纤耦合输出蓝光半导体激光加工光源研究。基于平面窗口TO封装的蓝光半导体激光单管器件,设计采用长后工作距的快轴准直镜和慢轴准直镜分别准直,获得低发散角、高光束质量的单元准直光束;结合二维空间合束、偏振合束和光纤耦合,将144个蓝光单管器件耦合进200μm/NA 0.22光纤,通过ZEMAX软件对半导体激光光路进行光线追踪模拟;并从实验上实现,3 A电流驱动下,200μm/NA 0.22光纤输出连续功率523 W,电光转换效率29%。该激光光源具有直接加工铜、金等材料的能力。 相似文献
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为实现二极管激光器垂直阵列输出光束具有小发散角、高指向精度的特点,简述了快轴准直(FAC)微透镜的光束准直原理,分析了调节装置的精度要求及透镜选择等问题。通过光学成像方法实时监测二极管激光bar条的近场像和远场像,对FAC透镜分别进行粗调节和细调节,获得了20个bar条连续输出2 kW,垂直阵列二极管激光快轴准直光束远场发散角4.4 mrad,bar条间准直光束指向精度不大于±1.7 mrad的准直效果,并对监测精度进行了简要分析。对影响光束准直效果的因素进行了分析,指出了工艺优化的重点。 相似文献
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这是一台把高强度空间相干激光束转换成空间非相干辐射光源的装置。它可使空间相干激光光束的时间相干性、频率特性以及偏振保持不变。激光是定向的,所以输出的相干光束投射在光学透镜上,使相干光束在用氢氟酸腐蚀过的毛玻璃片上成象,构成空间扩散体。从扩散器散射出的辐射光转换成空间非相干辐射光,但仍保留一些相干光束的重要特征,即偏振和瞬时相干性。扩散器将一束非相干辐射的发散光束输入到准直仪,以提供准直输出光束,可作为一种“眼睛安全”的方法用于激光通讯、激光测距和其他激光领域的装置。 相似文献
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介绍采用瞄准指示器提高诊断包瞄准精度的方法。基于高斯光束薄透镜变换原理分析由单模光纤耦合输出的激光经过瞄准指示器的光学系统后的传输特性,提出近轴放大率是影响瞄准指示器像方光斑大小的主要因素。设计一个以光纤耦合输出激光为光源,工作波长为635nm,总长小于100mm,瞄准距离(600~1500)mm,在靶心处相应光斑大小为(46.2~71.9)μm的神光-Ⅲ诊断包瞄准指示器光学系统。该激光光学系统采用3片普通光学玻璃,其中固定组由正负分离的2片玻璃组成,变焦组为单片负透镜。最后利用点扩散函数和波像差进行质量评价,结果表明该光学系统设计指标达到技术要求。 相似文献
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为了降低部分相干光光学系统设计的复杂度及成本,增加部分相干光应用的便捷性,提出了一种液晶空间光调制器的激光相干度及束散角复合控制方法。首先介绍了对激光光束进行相干度和束散角复合控制的基本理论和方法;然后分别设置了相干度和束散角检测实验,检测了本方法所调制激光光束的相干度和束散角的准确性。实验结果表明,采用液晶空间光调制器生成相干度为0.9 mm、束散角为7.5 mrad,以及相干度为1.5 mm、束散角为3.8 mrad的部分相干光束,其相干度与理论值相比误差在5%以内,其相干度均方根误差分别为0.027386和0.031314,峰谷值分别为0.084658和0.089103;其束散角与理论值相比误差在5%以内,其束散角均方根误差分别为0.022478和0.023186,峰谷值分别为0.081201和0.092130。可见,该方法可以实现高精度的相干度及束散角复合控制。 相似文献
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Suye Lü 《Optics Communications》2008,281(13):3514-3521
Taking the partially coherent cosh-Gaussian beam (ChG) as an illustrative example, the far-field divergence angle and directionality of partially coherent beams are studied. There are three competing physical mechanisms, i.e., the spatial coherence, diffraction and decentration, which affect the far-field divergence angle of partially coherent ChG beams. Two partially coherent ChG beams may generate the same far-field divergence angle, and partially coherent ChG beams may also have the same far-field divergence angle as a fully coherent ChG beam or as a fully coherent Gaussian laser beam if the three physical mechanisms are appropriately balanced. The consistency of the directionality of partially coherent beams expressed in terms of the far-field divergence angle and in terms of the far-field radiant intensity distribution is examined. Generally, two partially coherent beams with the same far-field divergence angle have not certainly the same far-field radiant intensity distribution. However, under certain conditions, it is possible to achieve the consistency of the directionality expressed in terms of the far-field divergence angle and of the normalized far-field radiant intensity distribution. 相似文献
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Xiaoling Ji Yuan Ma Zhengcai Pu Xiaoqing Li 《Applied physics. B, Lasers and optics》2014,115(3):379-390
In this paper, taking the tilted and off-axis partially coherent beams as the active detection laser beams, the characteristics of the active detection laser beams reflected back by a cat-eye optical lens in atmospheric turbulence are studied analytically and numerically. The analytical expressions for the centroid position deviation γ, the average intensity, the mean-squared beam width and the far-field divergence angle at the receiver plane are derived. It is found that tilted and off-axis active detection laser beams cannot be reflected back by a cat-eye optical lens in the direction of the source. The absolute deviation $\left| \gamma \right|$ decreases as the beam coherence decreases. Therefore, partially coherent beams are more suitable as active detection laser beams than fully coherent ones. In addition, $\left| \gamma \right|$ decreases greatly due to the aperture effect, and the influence of turbulence on $\left| \gamma \right|$ is not monotonic. On the other hand, the influence of the beam coherence and the atmospheric turbulence on the average intensity, the mean-squared beam width and the far-field divergence angle at the receiver plane is also examined, and some interesting results are obtained. The results obtained in this paper are very useful for applications of the active laser detection. 相似文献
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LI Hong HAUNG Dexiu 《Chinese Journal of Lasers》2001,10(3):167-170
1 Introduction Highefficientcouplingbetweenchip(semiconductorlaserdiode)andsinglemodefiberisthekeytechnologyforopto electronicsintegrationinthefuturecommunication[1 ] .Butt couplingofsemiconductorlaserdiodewithsinglemodefiberleadstolargecouplinglossandse… 相似文献
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A novel semiconductor laser diode with a two-dimension nonlinearly tapered waveguide is proposed and its property is studied by Fourier expanding method. It is shown that coupling loss between the semiconductor laser diode and a single mode fiber is reduced effectively, the reduction role of the nonlinearly tapered waveguide is more apparent than that of a linearly tapered waveguide , the minimum coupling loss is 0.36 dB, and the far field divergence is decreased. The reduction mechanism is discussed. 相似文献
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In recent years the partially coherent beams have attracted very much due to novel properties and its applications. In this paper the tight focusing properties of radially polarized partially coherent dark hollow beam (DHB) through a high numerical aperture lens are investigated numerically based on vectorial Debye theory in detail. The result shows that the optical intensity distribution in the focal region directly fluctuates due to small change in coherence length and high numerical aperture angle of the focused radially polarized partially coherent DHB. 相似文献
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Libo Li Qihong Lou Jun Zhou Jingxing Dong Yunrong Wei Songtao Du Bing He 《Optics Communications》2008,281(4):655-657
To get high output power with good beam quality, a tapered section is introduced to large-mode-area (LMA) Yb-doped fiber laser. Output characteristics of the fiber laser without tapered section and with tapered section are compared experimentally. When the launched pump power is 119.1 W, 77.9 W with M2 3.08 and 56.4 W with M2 1.14 can be obtained, respectively. The corresponding slope efficiencies are 71.8% and 54.1%, respectively. Although output power of the tapered fiber laser has 30.6% penalty, brightness of it is as much as 5.28 times of the fiber laser without tapered section. Moreover, spectra of them are measured. It is found that tapered section makes lasing wavelength of the fiber laser shorter. 相似文献