Re: dispersion diagram slab waveguide; problems with symmetry
"Steven G. Johnson" <[email protected]>
| Newsgroups | gmane.comp.science.photonic-bands |
|---|---|
| Message-ID | <[email protected]> |
On Sep 16, 2010, at 5:44 AM, <[email protected]> <[email protected]> wrote: > I am trying to calculate the dispersion diagram for a photonic slab > waveguide. For this I use a 1-dimensional computational cell in the > z-direction. The waveguide itself is in the xy-plane and has a > thickness of > 1. In the attachments you find the Scheme file I used and a simple > bash > script with the commands I used to execute it. > > What I expected: > (run-zeven) yields bands TE0, TE1, TE2, ... > (run-zodd) yields bands TM0, TM1, TM2, ... > > What I found: > (run-zeven) yields bands TE0, TM1, ... > (run-zodd) yields bands TM0, TE1, ... > > What am I doing wrong? Probably you are just confused because there is more than one convention for "TE" and "TM" in the literature. The TE you are probably thinking of corresponds to run-yodd and the TM you are probably thinking of corresponds to run-yeven. The key thing is to figure out what is transverse to what in your TE/ TM convention, and what symmetry that corresponds to. (See chapter 3 of our photonic-crystals book, ab-initio.mit.edu/book, to understand how polarization corresponds to symmetry.) --SGJ