Angular dependence of screen speckle and fiber speckle of coupled output of nine high-power blue laser diodes through a multi-mode fiber
Angular dependence of screen speckle and fiber speckle of coupled output of nine high-power blue laser diodes through a multi-mode fiber
复制标题
九个高功率蓝色激光二极管通过多模光纤耦合输出的屏幕散斑和光纤散斑的角度依赖性
DOI：
10.1007/s10043-015-0150-1
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发表时间：
2016
期刊：
影响因子：
1.2
通讯作者：
K. Tojo
中科院分区：
文献类型：
--
作者：
J. Kinoshita;Hitoshi Aizawa;A. Takamori;Kazuhisa Yamamoto;H. Murata;K. Tojo
研究了高功率蓝色激光模组连接的多模光纤投射出的散斑图的散斑对比度的角依赖性。激光模块有9个高功率InGaN/GaN蓝色激光二极管，排列成3乘3的阵列。每个排列的激光二极管对光纤的入射角略有不同。通过对实测数据的处理，我们成功地从混有粗纤维散斑的投影散斑中提取出细屏幕散斑。研究发现，在最靠近近轴方向的导光分量投影的中心区域周围，屏斑和光纤斑的散斑对比度都较大。这是因为阵列中中心激光器的输出比其他激光器更容易耦合到近轴模式。研究了散斑消减方法、光纤振动、扩散器和旋转扩散器对散斑对比度的影响。
Angular dependence of speckle contrast of speckle pattern projected out of a multi-mode fiber connected to a high-power blue laser module is investigated. The laser module has nine high-power InGaN/GaN blue laser diodes arranged in a three-by-three array. Each of the arrayed laser diodes have slightly different incident angle to the fiber. We have successfully extracted the fine screen speckle pattern from the projected pattern mixed up with the coarse fiber speckle pattern by processing the measured data. It is found that the speckle contrast of the both screen and fiber speckles are larger around the center area where the guided-light component closest to the paraxial direction is projected. This is because the output of the center laser in the array is likely to couple into the paraxial mode more than the rest. Speckle contrast behaviors when applying the speckle reduction methods, fiber vibration, diffuser, and spinning diffuser are also investigated.