Learning Forum

[Serein]

[Guilin Sun]

is 1e-12 THz correct? Please use correct frequency.

The source inside the analysis group uses the default simulation time of FDTD. Please significantly increase simulation time for FDTD, then the signal can be normal. may be 100 times (1e^5 fs) for 10THz.  

[Serein]

Thank you very much for your reply. I may not have described my issue clearly, which might have led to some misunderstanding. My question is that when I directly modify the frequency of the variable source in the S-parameter analysis group, I still see the frequency as 1e-12 THz when checking the source, which is clearly incorrect. For example, in the image below, I set the frequency of the S-parameter variable source to 10 THz, but the setting in the source remains unchanged at 1e-12 THz. I look forward to your response. Thank you.

[2022022503]

还有就是我想问一下，THz波段的光入射时，仿真非常快的就结束了，导致光没有完整传输就衰减完了，我想问一下增加仿真时间有对应标准吗。

如下图我的输入频率是0.7THz,然后仿真时间是1e+06fs,左图为我的仿真结果，右图为文献中的图

[Guilin Sun]

Please open the analysis group, and check how does the input frequency is assigned to the source. Maybe it assues the frequency is in THz but if you show the data it would be in Hz. 

[2022022503]

我有试过，但是有个问题就是当我在分析组输入的频率不管是多少THz（只要单位是THz），其在源中都是1e-12THz不变

[Guilin Sun]

关于频率，你要看看是否在Model里面控制；

分析组里可以显示一下频率看看是多少。

如果还有问题，建议重新用空白新文件设置仿真文件。总是要找到能直接控制频率的方法。

第二，增加仿真时间没有什么标准，主要取决于结构是否有强谐振，不可以用器件厚度除以介质内速度计算。因为仿真是根据最小autoshutoff min停止的，你把仿真时间设置的非常长都不影响实际仿真，只不过软件估算的仿真时间不准确而已。

参见

Ansys Insight: 如何知道FDTD的仿真时间足够长

Ansys Insight: FDTD仿真过程进度条结束显示100%，这样结果可靠吗？

Ansys Insight: 为什么说仿真时间要足够长才能得到正确的频域结果