[Meep-discuss] Fwd: Problem with photonic crystal tutorial

[nataly kuritz]

Dear team,
I downloaded and run the code from the tutorial on page:
https://meep.readthedocs.io/en/latest/Python_Tutorials/Resonant_Modes_and_Transmission_in_a_Waveguide_Cavity/

The problem is that the results on city are:

harminv0:, frequency, imag. freq., Q, |amp|, amplitude, error
harminv0:, 0.235109393214226, -3.14979827803982e-4, 373.213413146792,
9.44684723593584, 6.69397286173395-6.66585703608155i,
3.35873386748359e-9

So the peak frequency is at 0.2351

and my results with the code is :
arminv0:, frequency, imag. freq., Q, |amp|, amplitude, error
harminv0:, 0.23445415345998347, -0.0003147812367147688, 372.40808236678396,
5.812143033288932, -3.7631074862435683-4.429450156214277i,
4.306831336563974e-09+0.0i
So the peak at 0.2345

Could you please help me to understand the origin of this difference?
I didn't do any changes to the code..

Thank You!

[Max Kellermeier]

Dear Nataly,

I ran the script as well and was able to verify your results. I have to mention that I’m not part of the development team – only a user – but since the deviation occurs only on the third digit I thought that the simulation in the documentation may have been performed with slightly different parameters. Because of that I ran the simulation additionally with a few different resolutions, and this is what I get:

Res | freq
---------- | ------
16 | 0.23435
20 | 0.23445
30 | 0.23485
40 | 0.23489
50 | 0.23492

It’s just a quick qualitative test, but it seems to still increase with increasing resolution. Could that be the relevant parameter?

Best regards,
Max

________________________________
From: meep-discuss <meep-discuss-***@ab-initio.mit.edu> on behalf of nataly kuritz <***@gmail.com>
Sent: Saturday, October 20, 2018 3:18:33 PM
To: meep-***@ab-initio.mit.edu
Subject: [Meep-discuss] Fwd: Problem with photonic crystal tutorial



Dear team,
I downloaded and run the code from the tutorial on page:
https://meep.readthedocs.io/en/latest/Python_Tutorials/Resonant_Modes_and_Transmission_in_a_Waveguide_Cavity/<https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fmeep.readthedocs.io%2Fen%2Flatest%2FPython_Tutorials%2FResonant_Modes_and_Transmission_in_a_Waveguide_Cavity%2F&data=02%7C01%7C%7C2491ecc8a31d417c39ff08d6368eddac%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636756384559385274&sdata=p5wDOWUDkAPSeFcuWT1oEym4Hsu72fU8Ev%2Ffx30a2Ec%3D&reserved=0>

The problem is that the results on city are:

harminv0:, frequency, imag. freq., Q, |amp|, amplitude, error
harminv0:, 0.235109393214226, -3.14979827803982e-4, 373.213413146792, 9.44684723593584, 6.69397286173395-6.66585703608155i, 3.35873386748359e-9


So the peak frequency is at 0.2351

and my results with the code is :
arminv0:, frequency, imag. freq., Q, |amp|, amplitude, error
harminv0:, 0.23445415345998347, -0.0003147812367147688, 372.40808236678396, 5.812143033288932, -3.7631074862435683-4.429450156214277i, 4.306831336563974e-09+0.0i
So the peak at 0.2345

Could you please help me to understand the origin of this difference?
I didn't do any changes to the code..

Thank You!