提出一种前端直接耦合光纤平凸透镜的聚合物直光锥光束准直系统。通过具体地对直光锥的端体结构参数进行优化设计以得到高耦合效率高准直精度的直接耦合式聚合物直光锥准直系统。并利用光线传输理论和仿真实验，论证了直光锥的锥角和锥长对准直效能的较大影响。结果表明，选择合适的锥角和锥长能达到十微弧度级的准直精度，能较好地满足空间光通信系统远距离发射和接收对于光束质量的要求。此外，理论数值和仿真实验同样验证了该直接耦合式直光锥准直系统对于较大发散角的发散光束具有较好的准直效果。

A polymer straight tapered fiber collimation system with a fiber plano-convex lens coupled directly into the front-end was developed. We demonstrate that the cone angle and taper length of polymer straight tapered fiber have remarkable effects on the collimation performance based on the theory of rays propagation and geometrical optics. We show that the collimation accuracy improves obviously with small cone angle of long straight tapered fiber. In addition, the cone angle and taper length are further optimally designed so that both the coupling efficiency and collimation accuracy are well balanced and maximized in the collimating process. This study can benefit the collimation of the emitted laser beam in free space optical communication systems.