Learning Forum

[Asha Devi]

Dear all,

 

I have a question which I must say is quite an interesting one.  

I had an old lumerical file, already in the layout mode and the data related to it was produced around 2018 (My colleague doesnot remember the version used at that time). This file has a plasmonic environment with a gold nanoparticle and a substrate and we are calculating the net power transmission out of a box using the Analysis Group. The power transmission vs wavelength plot is as below:

Now, when I run the same file using the 2021 R1 version, we get the following result:

Theses are results from exactly the same file. As you can see the new file produced has these spikes and the magnitude of power has increased manifold. Has Lumerical made some changes in the settings over the years to the programs, as there is quite a drastic change in the result. I can share the files too for more information, however I am unable to attach it here. Looking forward to any suggestions or comments as it will be extremely helpful.

 

With kind regards and sincerest thanks,

Asha

[Dimitris Polyzos]

Hello Asha, 

Thanks for contacting us.

I reckon that this difference eamantes from the updated materials used in the model for the newer version of Lumerical. I believe that the settings are kept the same at both models (different versions), so in order to get the same results at the newer version you have to modigy the settings of your model. These ripples could be due to not good fitting of the materials used in the new version of Lumerical. Please try to adjust this first. Then I would recommend to check the source, monitors and FDTD settings. However, I believe that this comes from the updated material properties between these versions. 

If that is OK for you, I would be interested to check your model at least for the new version 2023 R2.3 I have on my PC. Actually, in this forum you cannot share a model but you can share any screenshorts and details you have and I will try to recreated your model myself. 

Do you have a premium license of Lumerical? If not you can register for a premium license where  you can share your model with the the support .

I hope I helped.

Regards

Dimitris

[Asha Devi]

 

Hi Dimitris,

Thank you very much for your kind reply and please accept my sincerest apology for the late response. Your suggestions were indeed very helpful. 

We were actually waiting for the license of the new version of Lumerical 2023 R2 and as you have suggested, I run my simulation using this version. However, the differences were still there and the ripples still prominent. 

I then modified the settings in the material Explorer and indeed as you have correctly pointed out, the material fit between the experimental data and the FDTD simulated data were not good (Fig. 1). The Imaginary part of permitivity data were not matching and therefore I increased the imaginary weight to 30 and now it is closely matched (Fig. 2). I kept the max cofficients same as before (which is 6). 

I have got a much smoother plot now and no ripples (purple plot in Fig. 3). However, there is still a difference between the two plots (green is the data generated around 2018 using an older version).

Is it due to the updated materials in the new versions as you have mentioned? I can share the file with you, kindly let me know how to do that. 

Once again, thank you very much for the help.

With kind regards,

Asha

 

[Dimitris Polyzos]

Hello Asha,

I am glad I could help you with your queries. Regarding the difference in the plots it might be due to updated materials between versions. I can test the result on my PC where I have the 24R1 version. To share your model I would recommend to register for premium support. The following information can be found useful if you want to register for technical support:

Lumerical support registration is a simple process that allows Lumerical users to access commercial technical support and some technical resources such as Application Gallery files.

Technical support for commercial customers is provided via Lumerical support, not the Ansys customer portal. Support is valid for the duration of your license/subscription. Once the license expires, you will have to register for support with your current license. A Lumerical user account and an active Ansys Lumerical license is required to register for support.

I hope I helped. PLease feel free to reach out for any help you might need.

Kind regards

Dimitris

 

[Asha Devi]

Hi Dimitris,

Thank you very much for the help and the information about the commerical technical support. I have indeed contacted the Lumerical support team and will have a discussion with them soon.

With sincerest thanks again and kind regards,

Asha

 

[Dimitris Polyzos]

Hello Asha, 

Thanks for your reply. I am glad I could help.

Kind regards

Dimitris