On Fri, 3 Aug 2007, leppert, jan wrote: > I tryed to calculate the transmission spectra of a PBG-fiber (fiber with > large air-core and 3 rings of smaller air-cores around, in hex-lattice), but > I get values >> 1 (see atteched pic) after I normalized the flux with the > flux of an fiber without air holes. I don't know if this normalization is > right or if there is another fault in my .ctl-file.
When doing transmission calculations, you always have to think carefully about your normalization: what are you comparing to what? In your case, it sounds like you have two cases: a holey fiber with a point source *in* the fiber, and a solid fiber with a point source *in* the fiber, and in both cases you are calculating the flux after some distance in the fiber. If this is what you are doing, it is not reasonable to call the ratio of these two fluxes a "transmission" or expect it to be <= 1. The reason is that the same current source, in different surroundings, radiates a different amount of energy. This is because the local density of states is different. What your calculation shows, assuming it is correct, is that the local density of states is much larger in the tightly-confined holey-fiber core than it is in a fiber with no confining core. (This is just like what happens in the Purcell effect.) Steven _______________________________________________ meep-discuss mailing list [email protected] http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
