Transmission in function of time


How can I obtain the transmission spectrum in function of time for a particular wavelength in a photonic crystal waveguide?
At this time, I get this information by using a DFTMonitor and running simulations varying the simulation time. Can I do that in a single simulation?

I attached my simulations files.phc_waveguide.fsp (513.2 KB) run_simulations.lsf (636 Bytes)


Hi @lpedraza,

Thank you for your question. The transmission spectrum returned by the DFT monitors is the result of a Fourier transform, so there is no time dependence. To get transmission results you should let the simulation run until the fields have decayed in the simulation region (this is what the autoshutoff feature is for).

If you want to record the fields as a function of time, you can use a field time monitor.

I hope that helps. Let me know if you have any questions.

Best Regards,

Hi @kjohnson,
Thanks for reply. I want to monitor how the transmitted power change in time. As illustrated in the plot.
So, I need to record the filed using the field time monitor and then integrate the poynting vector over the area of interest. Is this correct?


Yes, that will give you the instantaneous power through the monitor as a function of time.