; Compute the band structure for a Bragg mirror consisting of a ; sinusoidally-varying dielectric index. ; The index will vary sinusoidally between index-min and index-max: (define-param index-min 1) (define-param index-max 3) (define pi (* 4 (atan 1))) ; 3.14159... ; Define a function of position p (in the lattice basis) that returns ; the material at that position. In this case, we use the function: ; index-min + 0.5 * (index-max - index-min) ; * (1 + cos(2*pi*x)) ; This is periodic, and also has inversion symmetry. (define (eps-func p) (make dielectric (index (+ index-min (* 0.5 (- index-max index-min) (+ 1 (cos (* 2 pi (vector3-x p))))))))) (set! geometry-lattice (make lattice (size 1 no-size no-size))) ; 1d cell ; We'll just make it the default material, so that it goes everywhere. (set! default-material (make material-function (material-func eps-func))) (set! k-points (interpolate 9 (list (vector3 0 0 0) (vector3 0.5 0 0)))) (set-param! resolution 32) (set-param! num-bands 8) ; the TM and TE bands are degenerate, so we only need TM: (run-tm)
