Photonic Crystal Waveguide for Green Light

fdtd
photoniccrystals
waveguide

#1

Hi,
Based on my previous question,previous post link I was able to compute the photonic band structure for my material i.e. diamond.

The band structure I got was:

Based on this paper, jlt-18-10-1402.pdf (1.5 MB) I calculated the parameters for my lattice constant, slab thickness and radius of the holes.

I want to propagate only green light (530nm - 540nm) through my photonic crystal waveguide which I am getting very weird results.

This is my simulation file:
PhC_wg_green.fsp (1.6 MB)

Can you please take a look and see what is the problem is? Please help!

Thanks,
Sourangsu


#2

Dear @sourangsu.banerji

Can you please clarify what you mean by weird results?

Looking at your simulation file, if your result does not have enough resolutions, you can increase the number of frequency points from Set global monitor settings. If the results itself don’t make sense, can you please explain what were you expecting to see? If you are trying to replicate the results of a specific paper, feel free to share it here with us.

Thanks


#3

@bkhanaliloo…thanks for your reply.

I increased the number of frequency points by around 10.

This is the result I got:

I was saying it is weird because how can one have a transmission greater than 1? But then my transmission plot is showing that.

Secondly, as per the results that I am trying to achieve should look more or less like this:

You see, I want green light (wavelength - 532nm) to propagate through my waveguide.

This is my latest simulation file.
PhC_wg_green.fsp (1.6 MB)

I hope I was able to explain my problem properly. Can you please check if the modeling was done correctly or not?


#4

Dear @sourangsu.banerji

The choose of Periodic and Bloch BC does not seem to be chosen correctly. I think that you need to use PML in all three directions and increase the size of PC and holes if you want to simulate a bigger device.

Also please note that your current simulation file is different than what you calculated in band structure calculation file: since your band-structure calculation uses a single hole, it means that your device should be repeated in all directions while this is not the case in your recent simulation file as periodicity changes in y-direction:

For example, holes inside the green box are shifted compared to the holes in red box.

Thanks