Reply To: Negative value of intensity spectrum with the far field project analysis

[Guilin Sun]

My previous reply was not shown properly.

Since I do not know your analysis script, I can only say that, if you are using Poynting vector to calculate the transmission, it is normal to have "negative" transmission:

It integrates the poynting vector dot the monitor surface norm. The monitor surface norm is always toward the positive axis. When the light propagates along the negative axis, the dot result is negative.

You can simply filp the sign. In visualizer, you can use "-Re".

If you use intensity integration, it should be positive since intensity is always positive.

Please check your script.