Learning Forum

[Leonid Pascar]

Hi,

I used so far the mode expnasion monitor to exteact the transmission specturm of my device. Now, i need also to extract the phase response.  I read this web page and I think that the 'angle operation' of the 'a' parameter should relate to the response. Is that correct? Do I need to use another monitior for referencing to the input mode?

Thanks, 

Leonid

[Dimitris Polyzos]

Hello Leonid, 

Yes you are correct. The phase response can be extracted from the angle. A simple script command on how to achieve that is the following:

Sa=getresult("FDTD::ports::port 2","S");
S21=Sa.S;
Phase=angle(S21);
?phase*180/pi;  

the script command is from a FDTD solver with 2 ports. You can modify the script commands to your model. Let me know if you need further help with that. IO hope I helped.

Kind regards and Happy New Year.

Dimitris

 

[Leonid Pascar]

Hi Dimtris,

 

Happy new year and thank you for the response! I use the  mode expnasion monitor instead of ports (as I analyze results obtained via LumOpt optimization). I see there the 'angle operation' of parameter 'a' , but I am not sure if I need to reference it to something else. Do you know about how to retrive the phase response via the mode expnasion monitior?

With regards,

Leonid

 

[Dimitris Polyzos]

Hello,

Yes you are correct, the angle of operation is referred to the phase. You can use imple script commands as you would extract the electric field or other results from the script workspace. More information can be found in this link :

Introduction-to-Lumerical-datasets

Regards

Dimitris

[Leonid Pascar]

Hi Dimtris,

Thanks for the reply, the missing point for me is the refeence to the input. I am intersted to know about the relative phase response to the input. In the case of the expnasion mode monitor (described here). I understand the paramter of interset is 'a'. I am not sure if I can assume thae the angle of 'a' represents the phase realtive to the input or an unrefrenced global value. Could you please clairfy this point?

 

With regards,

Leonid

[Dimitris Polyzos]

Hello Leonid, 

Thanks for your reply. The phase (angle "a") is referenced to the input modal field propagation and it depends on the location of the monitors and the mesh size. I assume that you use a source with input mode, its position relative to the recording monitor position, in the waveguide for example, will return a phase difference. You can check that by adding some  monitors with a specific spacing between them and check the phase compared to the source monitor. I would expect that the phase would increase as you check the monitors further away from the source. A schematic of you model would be helpful as well.

I hope I helped. Let me know if you need further assistance.

Kind regards

Dimitris

[Leonid Pascar]

Thank you for the explanation