Learning Forum

[vahram.voskerchyan3]

I am trying to simulate a grating coupler, and I plug in the calculated intenisty as a new mode amplitude an relaunching the simulation again. But after some value the intensity starts to drop significantly. For example when mode amplitude is 1 I get intensity of 0.956, then I replug this value and get 0.87456 and so on but after the value is 0.733184 for mode aplitude suddenly the new intensity value is 0.5142. How can the drop be so big if the simulation stays the same, and only thing that is changing is the mode amplitude from recalculated intenisty profile ?

The attached is a schematic of the simulation setup: 

 

Here I change the intensity changes at the output after adjusting the mode amplitude: 

And here is the intensity field and the mode setup:

The simulation setup looks as follows:

 

[Guilin Sun]

 

The mode source is injecting the mode horizontally, right? where is the monitor?

If there is no material gain, the output is proportional to the input, in magnitude, but not in intensity.

If the attenuation is along the propagation diraction, I believe it is physical as some power is coupled out.