Near-field speckles produced by random self-affine surfaces and their contrast transitions.
By use of a numerical calculation based on Green's integral equation, we study the near-field speckles produced by the random self-affine fractal surfaces of a dielectric medium. The speckle intensities evolve considerably in the near-field region, and the local fluctuations in them disappear before they have traversed the distance of a wavelength. The transition of the speckle contrast either on the surface or in the near field and in the neighborhood non-near-field regions depends on lateral correlation length xi and roughness exponent alpha of the random surfaces.
Cheng
Chuanfu
C
Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P.O. Box 800-211, Shanghai, China. chengchuanfu@yahoo.com
Liu
Chunxiang
C
Ren
Xiaorong
X
Liu
Man
M
Teng
Shuyun
S
Xu
Zhizhan
Z