垂直腔面发射激光器与多模光纤的直接耦合

Direct Coupling between VCSEL and Multimode Fiber

使用重叠积分法,从理论上研究了垂直腔面发射激光器(VCSEL)与多模光纤 MMF之间的直接耦合。首先得出了具有拉盖尔-高斯函数形式的VCSEL与MMF的模场表达式,并给出了相应的模场半径的计算公式;然后利用重叠积分公式,结合matlab的计算结果,重点研究VCSEL与MMF对准时的耦合情况,指出VCSEL和多模光纤的模场半径的匹配对耦合效率具有重要的影响;最后利用VCSEL与MMF端面坐标系变换,给出了偏心激励情况下的耦合效率公式。

By using the method of overlapping integral, this work reports a theoretical study on the direct coupling between vertical cavity surface emitting laser (VCSEL) and multimode fiber (MMF). We deduce the expressions of VCSEL and MMF modal field, known as Laguerre-Gauss functions, and give the formula of their modal radii. In the way of overlapping integral, we place an emphasis on the coupling between VCSEL and MMF without misalignment, combined with the results from matlab and point out that the matching between the modal radii of VCSEL and MMF plays a key role on the couple efficiency. In the last, we make use of transform of the coordinates on the end plane of VCSEL and MMF to give the coupling formula for the offset excitement.