High Q H0 Photonic Crystal cavity matching Qfactor of paper

[megan.nantel]

Hi everyone,

I’m pretty new to using FDTD and I’m trying to get my simulations to match a paper by Minkov et al. https://www.nature.com/articles/srep05124

I am trying to match their H0 cavity (Design 2). I began working with their parameters at 1550 nm and then scaled up everything for resonance at 2900 nm. I have good agreement in the mode volume BUT my quality factor is only about only half of theirs.

I got a Q=1.15e9 (paper gives 1.9e6) at 1550 nm.

I’m wondering if the meshing, FDTD geometry, etc have an effect on this? I’ve tried playing around but without much change.

Can anyone see what I could be doing wrong that would yield this lower Q factor?

1550 nm file, google drive link: https://drive.google.com/open?id=0B__ZKNontc3mUkhHOFZLNXI0THM
2900 nm file, google drive link: https://drive.google.com/open?id=0B__ZKNontc3mazBaNjJ4OFhkMFk
Many thanks in advance!

[gbaethge]

Hi @megan.nantel,

I noticed you set the y min boundary condition to anti-symmetric, which is not compatible with the polarization of the sources. There’s some further testing to do, in order to get the correct results.

A good start is the Photonic Crystal and Diffractive Optics page and the Cavities and Resonator video. These pages will give you some insight about how to set up such simulations.

More generally, there’s many factors that affect the accuracy of the simulation. You can find some information about the sources of error in the convergence testing page.

I hope this will help!