We report the theoretical analysis of the coupling optics involving laser diode to single-mode circular core graded index fiber excitation via upside down tapered parabolic microlens on the fiber in presence of possible transverse and angular misalignments. We use the relevant ABCD matrix appropriate for such type of coupling device in order to prescribe analytical expressions of coupling efficiencies in presence of the said misalignments. The prescribed expressions are employed for estimation of the concerned coupling optics. The execution of our formalism involves little computation and as such the present formalism will prove user friendly to the system engineers. The results obtained will be useful to the designers and packagers in the context of maximum launch optics of such coupling device.

我们报告了耦合光学的理论分析，涉及激光二极管到单模圆形纤芯渐变折射率光纤的激发，该光纤在可能存在横向和角度失准的情况下通过光纤上的倒置锥形抛物线微透镜而激发。我们使用适合于这种类型的耦合装置的相关ABCD矩阵，以便在存在所述失准的情况下规定耦合效率的解析表达式。规定的表达式用于估计有关的耦合光学器件。我们的形式主义的执行涉及很少的计算，因此，当前的形式主义将证明对系统工程师用户友好。在这种耦合装置的最大发射光学器件的背景下，获得的结果对于设计者和包装者将是有用的。