[Paulo LourencoParticipant]

Hi Steve,

Thank you for your clarification. Completely elucidated me and, I think, anyone who might have an identical question…

Best regards.

[Paulo LourencoParticipant]

Hi Scott,

You mean use an observation area to monitor overlapping fields? I think I fail to understand. Could you please elaborate a bit more…?

Thank you again.

[Paulo LourencoParticipant]

Hi Scott,

Right, keeping PBC would most probably lead to an increase of workspace simulation, which on a 3D simulation means more needed resources and longer simulation time; PML would be used for device’s simulation and selecting the input field accordingly…

Thank you for all your help.

[Paulo LourencoParticipant]

Hi Scott,

Yes, a metallic film with just one hole.

Thank you.

[Paulo LourencoParticipant]

Hi Scott,

Thanks a lot for your explanation. I am clarified now as far as this case is concerned though, I have one other question 🙂 if I may: – Does this mean that if I want to analyze reflection I should increase the number of time steps to insure that EM field goes forth and back (may put another obervation point before the input field to check reflected field arrival)?

Best regards.

[Paulo LourencoParticipant]

Hi guys,

I apologize for jumping into this topic but maybe you can clarify my doubts about convergence time and time steps, together with time step size. In an usual simulation (let’s say a 2D silicon waveguide in air simulation), if we keep all options to “auto” at the Simulation Parameters window, we find that the EM energy almost reaches (see Note: please) the end of simulation. Is this to prevent the interference of the reflected wave? If so, shouldn’t APML be able to cancel out all reflections?

As Scott and Damian mentioned, if there are resonant features or cavities we should increase our spatial resolution. For a higher spatial resolution shouldn’t we also increase the number of time steps or is it better to keep it “auto”? I mentioned this because whenever I increase simulation time steps, field amplitudes vary…

Note: I am attaching an image of what I mean by “… EM energy almost reaches…”.

Thank you in advance.

Best regards.

[Paulo LourencoParticipant]

Hi Scott,

I cannot find your attached file but I created a simple test and verified it. Thank you for the insight…

Best regards.

[Paulo LourencoParticipant]

Hi Scott,

I want to model the propagation within a waveguide but, as far as I know, if this waveguide supports more than the fundamental mode you can only simulate each mode individually. What about if we want to model propagation within a multimode waveguide?

Thank you for answering.

[Paulo LourencoParticipant]

Hi Hyeong-Min,

I assume the step 6 you are talking about is the following:
– “… Repeat step 3 to 4 for Observationline2, reflection spectrum can be calculated, (refer to Figure 9).”.
Being this the case, I think the reflection spectrum is referring to the Observation Line window when on the Analyzer. If you look at https://optiwave.com/optifdtd-manuals/fdtd-enhancement/ on “Performing data analysis” there is a description on how to do it.

Best regards.
PL

[Paulo LourencoParticipant]

Hi Damian.

Thank you for your efforts on solving this issue.

Best regards.

[Paulo LourencoParticipant]

Hi guys.

Attached the project file…

Thank you.

[Paulo LourencoParticipant]

Yes, will do for sure. Thx Damian…

Note: each iteration of the script takes more than one hour on an i7, 8GB ram.

[Paulo LourencoParticipant]

Hi again.

I really need help with this script for my 64bit license is almost finishing and I do not understand why this is not working. Layout script works when there is no tick on “Simulate using script” and when I test the script with a larger NumIterations, I can observe the effect of radius variable on the layout designer; looks like there is something wrong in file creation instructions…

Const NumIterations=1

For x=1 to NumIterations
ParamMgr.SetParam "radius",13-x*0.1
ParamMgr.Simulate

Call Sub_PowerAtCenterWavelength("ObservationArea1", x, True)

WGMgr.Sleep(50)
Next

' Simulation and VB-post-data- analysis finished

'''''Start of sample code for the power calculation'''''''''

''''''''''''Calculate the Power At Center Wavelength'''''''''''''''''
'LineName - String - The name of the observation line
'IterationNum - Integer - The current iteration number in case of sweep simulation
'OutputIterationNum - Boolean - Indicate if the iteration number should be stored into the file.
'Sample: Call Sub_PowerAtCenterWavelength("ObservationLine1", nIteration, True)
Sub Sub_PowerAtCenterWavelength( AreaName, IterationNum, OutputIterationNum )
Dim error_msg 'for error handling
Dim fhs, ios 'for the output of the result
Dim power_val 'the Power At Center Wavelength
Dim observation_area 'The line object to the LineName.
Dim file_for_output 'The file name for storing the result.
Dim P_total

'Get the observation area.
Set observation_area = ObservePtMgr.GetObjFromID(AreaName)
'Calcualte the power at center wavelength.
P_total = observation_area.GetPowerTypeID(1)
power_val = observation_area.CalculatePowerRatioCWTotal()

'Save the result to the file.
If AppMgr.RunsInSimulator() = True Then
'Prepare the file for output.
Set fhs = CreateObject("Scripting.FileSystemObject")
file_for_output = GetOutputFileName("_PowerAtCenterWavelength.txt")
'Open for appending
Set ios = fhs.OpenTextFile(file_for_output, 8, True)

'Is there an error during the calculation?
' If observation_area.HasErrorsInPowerCalc() = True Then
' error_msg = observation_area.GetErrorMsg()
' ios.WriteLine( error_msg )
' Else
If OutputIterationNum Then
ios.WriteLine(CStr(power_val))
Else
ios.WriteLine(CStr(power_val))
End If
ios.Close 'Close the file
End If

' End If
End Sub

'Helper function
'Postfix - String - will be appended to the file(of FDT) name.
'Sample: file_name = GetOutputFileName("ThePower.txt")
Function GetOutputFileName( Postfix )
Dim project_folder
Dim file_name

project_folder = AppMgr.GetProjectFolderName()
file_name = AppMgr.GetProjectFileName()
file_name = Left(file_name, Len(file_name) - 4)
file_name = file_name&PostFix
GetOutputFileName = project_folder&file_name
End Function
'''''End of sample code the for power calculatio

Whenever I run the script, no matter what value NumIterations has, I can not get past the attached print screen.
Any help would be much appreciated. Thank you up front…

[Paulo LourencoParticipant]

Thanks Tamer, I think I will need it :-)…
Same to you.

[Paulo LourencoParticipant]

Thx Tamer for your answer. Already done it and 2D script simulation goes on with no errors (I had to include an observation line for 2D sim…) and completes the process. Only 3D simulation gets stuck. I am attaching the print screen…