Learning Forum

[Ahmet Baran Kaygusuz]

Hi,

I try to simulate an optical transmission system including an optical fiber element with nonzero dispersion. I expect to observe power fading at certain frequencies depending on fiber length and dispersion coefficient on signal after propagating through fiber. However, there is no power fading when analyzing the signal with scope. My question is why there is no power fading on signal due to dispersion, what would be wrong?

Thanks.

[Guilin Sun]

I guess this is mainly due to the propagation length. How long did you simulate the fiber, and what software you use for the simulation? INTERCONNECT? could you estimate the proper fiber length that the power drops to 50%?  You may also check if the non-zero dispersion feature is enabled, and if the model is for broadband or single frequency.  

[Ahmet Baran Kaygusuz]

I use  INTERCONNECT for simulation. The fiber length is  3 km and I tried by setting time window to 0.1 ms. I also set dispersion to 6 ps/nm/km, do I need to set anyting else, you have mentioned that non-zero dispersion feature is enabled. I both tried single frequency and broadband, I think it is not important, is it?

 

[GWANG]

Hi Ahmet Baran Kaygusuz,

The settings look good to me. Could you please let me know which fiber model you are using exactly? There are two fiber models, linear and nonlinear. The nonlinear model is block mode only so you probably wouldn't notice any power fading over time. 

[Ahmet Baran Kaygusuz]

I am using optical linear fiber model and block mode. My expectation is that power fading occurs at certain frequencies, as I simulated in MATLAB. But the spectrum in Lumerical is flat. The mode of fiber is true, I also tries dispersion and enabled but nothing changed.

[Ahmet Baran Kaygusuz]

Is it possible to upload or e-mail *.icp file that I  try to simulate, and you check the settings?