Fig. 1. Schematic diagram of super-surface structure of spiral distribution: (a) Number of segments of helix is equal to 1; (b) number of segments of helix is equal to 2.螺线分布的超表面结构示意图　(a)螺线的段数 ; (b)螺线的段数

Fig. 2. The obtained electric field intensity and phase distribution when distance between inner and outer spirals is equal to 0: (a)−(c) ; (d)−(f) ; (g)−(i) ; (j)−(l) . 内外两层螺线之间的距离 时的结构示意图、电场强度以及相位分布图　(a)−(c) ; (d)−(f) ; (g)−(i) ; (j)−(l)

Fig. 3. The obtained electric field intensity and phase distribution when distance between inner and outer spirals is equal to : (a)−(c) ; (d)−(f) ; (g)−(i) ; (j)−(l) ; (m)−(o) . 内外两层螺线之间的距离 时的结构示意图、电场强度以及相位分布图　(a)−(c) ; (d)−(f) ; (g)−(i) ; (j)−(l) ; (m)−(o)