Learning Forum

[cgutie22]

I have been working on the small-scale metalens-field propagation app using 2022 R1.1 version 8.27.2963 and having a few issues.

First, I noticed that the file "unit_cell.fsp" will not open, giving me an error stating "Error reading file". Why is this the case, and what is the significance of this file?

Second, I noticed that the "unit_cell_fdtd.fsp" file has optimization/sweep variables called "height" and "radius". When I try to edit these sweep variables and try to run "unit_cell_fdtd.lsf", the sweep variables will reset to what they were before. Where can I edit this so that I can change the height and radii of the sweep?

 

Lastly, where does the index of refraction for the pillars come from? I have a set index of refraction I would like to use for my material, but it looks like the code references a Matlab data file for the index of refraction of the material. Why is this?

[Guilin Sun]

Sorry to reply you late as this post was missed previously.

1: Please install the latest version and test. I tested with R2024R1 and it works fine.

2: "When I try to edit these sweep variables and try to run "unit_cell_fdtd.lsf", the sweep variables will reset to what they were before"

Did you click "ok" or better "apply"?  I modified and clicked "ok", it works fine:

Please install the latest version and see if it works.

[cgutie22]

Thank you for your reply and your patience. It took a while to implement your advice, as I had some license issues. After following your question, I found that I can edit the parameters in unit_cell_fdtd, but still have a couple of issues.

In "unit_cell_fdtd", I noticed in the sweep that E would get the information from s_params. After changing the wavelength in s_params and clicking "ok", I noticed that the matlab file "EH_and_phase_vs_radius_fdtd" would print the wavelength as 6.6e-7. I also changed the source and reran the simulation, but the wavelength remains 6.6e-7. I will delete all the matlab files and run "unit_cell_fdtd", but I noticed the newly generated matlab file would have wavelength = 6.6e-7. Is there something else I am supposed to change so the wavelength in this file is also changed? I would just edit line 49, but I'm worried I may be incorrectly editing some parameters.

My next question regards "unit_cell". I will not run "unit_cell.lsf" without editing it, and I notice "unit_cell" will only run up to 83, giving an error "... in 3D interp, if the first argument has a size of NxMxP, the fourth argument must have length P". Did you also get this error? As this is an example, shouldn't I just be able to run this code?

Thank you so much for your response.

[Guilin Sun]

As long as you change the start/stop wavelength in "s_params" it should change the source wavelength (single wavelength in this case)

Please check the script and find which line has the issue, and then check the dimension of the matrix.

I checked and found that Ex has dimension of 

 ?size(Ex);
result: 
50  50  11  

eg, 11 points for radius sweep.

however the radius is changed to 51 points:

?size(grating_characterization.radius);
result: 
1  51  

I would suggest you to modify the sweep points for radius from 51 to 11.

I guess the uploaded file was modified after the script file uploaded.