Guilin Sun
Ansys Employee

For the decomposition of the circular polarization, it is simply by definition. Please check some reference as this is a theoretical question.

For simulation, it is coincidence that your TFSF gives "looking" similar results. The project file has definiciency as you did not extend  the substrate:

Please modify as suggested. 

Ansys Insight: 我的仿真结果为什么与文献或实验结果不一致?

Please write a new post if you have questions, as I will take long vacation and your post will not be replied.