Dear Steven: > I am learning to use the programme , and I try an examples about photonic > crystal filled with liquid crystals in >the Reference( physical review B 67,073106 (2003)). But I find the result, the >dispersion relations of guided modes are so different compared with the >results in the Reference, which will be a error though their basic curves is >similar. > This is 2D triangular lattice photonic crystal with air holes in GaAs > substrate. The backgound dielectric index is 11.4. We calculalte the > dispersion relations of line defect waveguides filled with liquid crystal, > and the attached file is about the supercell, and Dark and light shaded > regions indicate GaAs and liquid crystals, respectively. When the rotation > angle of the director of the liquid crystal is 90°, the components of the > dielectric tensor are ne*ne,no*no,and zero in xx ,yy, and xy > directions,respectively, where ne is 1.706 ,and no is 1.522 ( this direction > is in accord with that in the supercell). I try some examples about liquid > crystals, and the problem is also present. Would you mind scanning my ctl > file? >(define-param supercell-y 10) ; the (odd) number of lateral supercell periods >(set! geometry-lattice (make lattice > (basis1 (/ (sqrt 3) 2) 0.5) > (basis2 (/ (sqrt 3) 2) -0.5) > (size 1 supercell-y no-size))) >(define-param eps 11.4) ; the dielectric constant of the bandground >(define-param r 0.45) ; the hole radius in the bulk crystal > >(set! default-material (make dielectric (epsilon eps))) >(set! geometry (list (make cylinder > (center 0 0 0) (radius r) (height infinity) > (material air)))) >(set! geometry > (append > ; duplicate the bulk crystal holes over the supercell: > (geometric-objects-lattice-duplicates geometry) > > ; add a rod of dielectric, to erase a row of holes and form a waveguide: > (list > (make cylinder (center 0 0 0) (radius r) (height infinity) > (material (make dielectric (epsilon eps))))) > (list > (make cylinder (center 0 0 0) (radius r) (height infinity) > (material (make dielectric-anisotropic (epsilon-diag 2.910436 > 2.316484 2.316484))))))) >(define Gamma (vector3 0 0 0)) >(define K' (lattice->reciprocal (vector3 0.5 0 0))) ; edge of Brillouin zone. >(set! k-points (interpolate 100 (list Gamma K'))) >; the bigger the supercell, the more bands you need to compute to get >; to the defect modes (the lowest band is "folded" supercell-y times): >(define-param extra-bands 6) ; number of extra bands to compute above the gap >(set! num-bands (+ supercell-y extra-bands)) > >(set-param! resolution 32) > (run-te > (output-at-kpoint (list-ref k-points (quotient(length k-points) 4)) > fix-hfield-phase output-hfield-z)) > > Thank you a lot. Look forward to your reply! >Best regards >Hongliang Ren > > > > > hlren >[EMAIL PROTECTED] > 2006-08-20
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致
礼！
hlren
[EMAIL PROTECTED]
2006-08-20
epsilon.png
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