Dear Steven and MPB's users:
I design a PC waveguide , the period of waveguide is not equal to the period
of crystal . The edge of Brillouin zone of cyrstal is K'=(0.5pi/a 0 0) along
the direction of waveguide. The edge of Brillouin zone of waveguide is K'=(pi/a
0 0). I think that if we use K'=(0.5pi/a 0 0), the mode of crystal which isnot
in gap will resemble the normal mode of crystal single period waveguide,and the
mode in gap will be folded. if we use K'=(pi/a 0 0), the mode of crystal which
isnot in gap will be symmetrical about the K'=(0.5pi/a 0 0), and the mode in
gap will not folded. But from the band map ,It seem to two "K'" isnot right.
what is the reason?
So, When i calculate the mode of the waveguide , how to define the k-point
,K'=?
the structure of PC waveguide:
* * * * * * * * * * * * * * * * *
* * * * * * * * * * * * * * * * *
* * * * * * * * * * * * * * * * *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* * * * * * * * * * * * * * * * *
* * * * * * * * * * * * * * * * *
* * * * * * * * * * * * * * * * *
My ctl
(define-param h 0.5) ; widelength of waveguide
(define-param r 0.3) ;
(define-param rd 0.2)
(define-param eps 1)
(define-param supercell-y (+ 8 h))
(set! default-material (make dielectric (epsilon 11.56)))
(set! geometry-lattice (make lattice
(basis1 1 0)
(basis2 0 1)
(size 1 supercell-y no-size)))
(set! geometry (append
(list (make block (center 0 0 0)(size a supercell-y
no-size)(material (make dielectric (epsilon 11.56)))))
(list (make cylinder (center 0 (+ (/ h 2) 0.5 ))(radius rd)(height infinity)
(material (make dielectric (epsilon 1)))))
(list (make cylinder (center 0 (+ (/ h 2) -0.5 ))(radius rd)(height infinity)
(material (make dielectric (epsilon 1)))))
(list (make cylinder (center 0.5 (+ (/ h 2) 0.5 ))(radius rd)(height infinity)
(material (make dielectric (epsilon 1)))))
(list (make cylinder (center 0.5 (+ (/ h 2) 0.5 ))(radius rd)(height infinity)
(material (make dielectric (epsilon 1)))))
(list (make cylinder (center 0 (+ (/ h 2) 1.5 ))(radius r)(height infinity)
(material (make dielectric (epsilon 1)))))
(list (make cylinder (center 0 (+ (/ h 2) -1.5 ))(radius r)(height infinity)
(material (make dielectric (epsilon 1)))))
(list (make cylinder (center 0 (+ (/ h 2) 2.5 ))(radius r)(height infinity)
(material (make dielectric (epsilon 1)))))
(list (make cylinder (center 0 (+ (/ h 2) -2.5 ))(radius r)(height infinity)
(material (make dielectric (epsilon 1)))))
(list (make cylinder (center 0 (+ (/ h 2) 3.5 ))(radius r)(height infinity)
(material (make dielectric (epsilon 1)))))
(list (make cylinder (center 0 (+ (/ h 2) -3.5 ))(radius r)(height infinity)
(material (make dielectric (epsilon 1)))))))
(define Gamma (vector3 0 0 0))
(define K' (lattice->reciprocal (vector3 ? 0 0)))
(set! k-points (interpolate 19 (list Gamma K')))
(define-param extra-bands 2)
(set! num-bands (+ 9 extra-bands))
(define-param res 32)
(set! grid-size (vector3 res (* res supercell-y) 1))
(run-te (output-at-kpoint K' fix-hfield-phase output-hfield-z))
To Administrator
I have send out the article with the same title ,
How to set k-points in piperiod pc waveguide? Fri, 20 Feb 2009 01:03:32 -0800
but it was shown by error. Would you delete the article? Thanks
-------------------------------------------------------------------
新浪空间——与朋友开心分享网络新生活！(http://space.sina.com.cn/ )
_______________________________________________
mpb-discuss mailing list
[email protected]
http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/mpb-discuss
