Learning Forum

[Nishith Narendra]

Hi,

I have been running FDTD simulations involving a gold nanorod on an InP waveguide.

XZ plane view:

XY plane view:

Below I show the normalized power transmittance at monitor 2 (labeled above):

These oscillations should not be existing (they indicate the presence of a Fabry Perot cavity).

I have verified the PML layers properly and performed the convergence test. Further, it seems that the mode source is acting like a reflector forming a cavity between the mode source and the nanorod.

As you can see below, the power transmittance at monitor 2 is shown for different gaps between the nanorod and the mode source. The oscillation frequency increases with an increasing gap between the source and the nanorod.

 

Can you comment on this and help me solve this issue?

Let me know if you have more questions or if more clarification is needed.

 

[Guilin Sun]

It is not known for me if the device is a simple straight waveguide with a nano paritcle on it, or a MMI component with the nanoparticle?

if it is the former, please significnatly reduce the simulation length, with only about one wavelength, move the source and monitor close to the nanoparticle, with long simulation time and smaller autoshutoff min.

also make sure the PML is about hald wavelength thick to effetively absorb the EM eergy. From the scrrensot it seems PML is thin.