Re: triangular lattice of air holes PC slab with defect line's band structure

On Sun, 11 Mar 2007, Ryan Hao wrote:
> I want to plot the band structure of photonic crystals slab with defect 
> line which is used as waveguide. One example is shown by Fig.7 in 
> steven's paper"Linear waveguides in photonic-crystal slabs". The 
> structure is triangular lattice of air holes extending through both a 
> high-index ~e of 12.0! finite-height dielectric slab and low-index ~e of 
> 2.0! semi-infinite dielectric regions above and below. The holes have 
> lattice constant a and radius 0.3a, while the high-index slab is of 
> thickness 0.5a. I simulate this structure in MPB and get the band 
> structure. The band structrue looks similar to steven's Fig.7,at least 
> the trend is.But my figure is a little lower at each point compared with 
> Fig.7. I can't find what the problem is.Anyone can point out why my 
> figure is lower for the some structure? I think I specified the correct 
> geometry because I check by h5topng,and the picture is shown below:

How much is a "little lower"?  The accuracy of the MPB is better than the 
accuracy of the old code I was using for that paper (and I don't remember 
what resolution I was using then either).

Steven