[Noha AnousParticipant]

Also, please, I have something confusing me, how can I choose the FD solver parameters to guarantee correct mode solution?
I mean the mesh size and the dimensions of Krylov subspace.

Thanks a lot.

[Noha AnousParticipant]

And this is the design file of OptiMOde

Attachments:

1. Example1.mxd

[Noha AnousParticipant]

Example 1 is the Optimode exported file

Attachments:

1. Example1.f3d

[Noha AnousParticipant]

Yes, sure
I tried again to check my files an parameteres so as not to waste your time, but still I’m having this mesh size mismatch problem!

The files are attached here.

Thanks in advance

Kaminow_imitate is the file I’m trying to export the modes into.

Attachments:

1. Kaminow_imitate.fdt

[Noha AnousParticipant]

Thanks a lot Damian,
I really appreciate your help

I’ll study the document you sent and see what I can reach …

but mainly my question was if the OptiFDTD is reliable to extract all types of plasmonic modes,
as I tried OptiMode, and the modes I get there are more than what I get in OptiFDTD and somehow different !

Thanks again!

[Noha AnousParticipant]

Hi,

It’s not working .. I had the mesh sizes adjusted but still gives me the same message,

any hint about what numbers should I adjust and how to make the mesh sizes match?

Thanks a lot

[Noha AnousParticipant]

Thanks a lot,
That’s very useful,

but this implies that I have to do 3D simulation not 2D, right?
Because in 2D, an error keeps appearing to me: cannot initialize input field.

As for 3D, it seems to be working but it gives me the message that the no. of points in the exported field is not the same as that in the designer file, and I’m trying to solve this now.

Thanks a lot.

Regards,

[Noha AnousParticipant]

Dear Damian:

I really apologize for bothering you with so many questions,

first, about my first file (in which I referred to an IOP paper), I tried Set 3 in Drude model following the link you sent, and other sets as well, I only get a mode that it a decaying sinusoidal … it doesn’t seem like a plasmonic mode, this is at w.g. width of 50 nm.

second, as for my other file, I increased the w.g. width because I couldn’t get modes at 50 nm or smaller width + I need to study the effect of the width, so I need the file to operate at diff. wavelengths and different widths.

Do you have any idea what the problem maybe?
And please if you have any working file, please send it to me.

Thanks a lot ,
Really thanks.

[Noha AnousParticipant]

Dear Damian:

Thanks for your reply.
The no. of points in the mesh is something I considered, I minimized the mesh size to 1e-6 um , yet I’m facing the same mode problems, modes not found …

[Noha AnousParticipant]

Dear Damian, thanks a lot for your time, I’ll try this.

But actually I also have another problem,
in the attached file, I’m trying to find the effective index of the symmetric and antisymm. modes at different wavelengths, but I face the following:
1- At 0.2 um, and 0.3 um strange modes appear, at 0.4 um, 4 modes appear, then as we increase wavelength, they disappear again.
2- symmetric mode ONLY exists starting 0.4 um, disappears at 0.67 um,
3- at 0.67, 0.68, 0.69 um no modes at all exist ….
4- starting 0.7 um the antisymmetric mode starts to appear till 1.3 um
5- Beyond 1.3 um, no more modes exist…

Also, when I change the W.G. width to 2 um, I almost get no modes at most wavelengths …

I don’t know if I can trust these results, are they right or wrong … they seem strange.

I used the silver Lorentz-drude model of:
Rakic et al., Optical properties of metallic films for vertical-cavity optoelectronic devices, Applied Optics (1998)

Thanks in advance

Attachments:

1. rr_paper.fdt

[Noha AnousParticipant]

Dear Damian,

I was using the built in Ag model in Optiwave, but chose the option of Drude-only model …

Did it work properly when you used another Drude model?

Also I tried using Lorentz-Drude from Rakic’s paper, but still couldn’t get effective indices except at some wavelengths … and I have no idea what eh problem is.

Thanks a lot

[Noha AnousParticipant]

Thanks a lot Damian!

The file is attached and the reference I’m trying to imitate is:

http://iopscience.iop.org/2040-8986/14/5/055001

I’m trying to simulate the design in Fig 2(a)(the linear ring not the one with the non-linear material … at least as a beginning :))
which is a dielectric ring with n = 1.12 on a Silver wafer using Drude model.

The dimensions are as follows:
Rcore = 100 nm
Waveguide width = 50 nm
gap between ring and waveguide is 10 nm.

Actually, using the previous design, I can’t even determine the effective index of the modes that’ll propagate in the structure … I get no modes!

and please if an example for a plasmoni ring (the ring itself is metal) is added to the manual or OptiFDTD site, that will be very useful …

Thanks a lot for your help,

Attachments:

1. IOP.fdt

[Noha AnousParticipant]

Dear Damian,
Thanks for the prism file comaptible with the 32 bits,
but I have some questions if you please:

1 – To compute the effective index of the structure, shall I choose 2D modal, then when computing the mode, shall I click on the 3 waveguides?? or only the gold to compute the plasmonic mode?
(When I choose the three waveguide, I do not get a mode)

2- On the other hand, only choosing the gold layer, gives me only 1 symmetrical mode … there is supposed to be another antisymmetrical mode which doesn’t appear even when I increase the no. of modes to be computed!

3 – How is it possible to increase the resolution in the modal solutions?? It is set to 401 points, is it possible I’m not getting the anti-symmetrical mode because of the low resolution?

4- As for the ring example you mentioned earlier, it’s a dielectric ring, is there an example for a plasmonic ring because I’m facing some problems with that?

Thanks a lot in advance.

Noha