Reply To: How to observe the phase of circularly polarized light

[yanshengshao67]

Thanks for your reply!
Unfortunately, I just started the simulation of FDTD recently, and my electromagnetic foundation is relatively weak, so after some attempts, I still have several questions I would like to confirm with you:
1. You said that if TFST is larger than periodic, its action is the same as that of a plane wave. Here, I expanded its range by 30nm and its structure by 30nm. The problem of energy attenuation has indeed been solved, but the simulated curve will have many peaks, I don't know whether they are diffraction peaks. 

2. I scaled the TFSF to the original coverage area (the same size as the structure) and checked the spectrum of the time monitor you mentioned. I followed the following process, I wonder if there is any problem: Time monitor -> Visualizer -> spectrum. If there is no problem, I will leave the screenshot below. There is indeed obvious resonance in the band I am interested in (530nm-1550nm), and I am also conducting simulation according to what you said, extending the simulation time to 10^4fs and reducing the autoshutoff min to 10^-6.

3. Regarding the phase problem of circular polarization, I know that circular polarization can be composed of two linear polarization with a phase difference of pi/2, but I do not know how to use FDTD to operate, can you tell me some specific operations to solve the phase of circular polarized light?
Thank you, teacher. Look forward to hearing from you