Speckle correlations in the light scattered from a weakly rough one-dimensional random metal surface

Abstract

Perturbation theory is used to compute the angular-intensity correlation function C(q, k|q(?), k(?)) = ?[I(q|k) - ?I(q|k)?][I(q(?)|k(?)) - ?I(q(?)|k(?))]? for p-polarized light scattered from a weakly rough, one-dimensional random metal surface. I(q|k) is the squared modulus of the scattering matrix for the system, and q , q(?) and k , k(?) are the projections on the mean scattering surface of the wave vectors of the scattered and the incident light, respectively. Contributions to C include (a) short-range memory effect and time-reversed memory effect terms, C((1)) ; (b) an additional short-range term of comparable magnitude C((10)) ; (c) a long-range term C((2)) ; (d) an infinite-range term C((3)) ; and (e) a new term C((1.5)) that along with C((2)) displays peaks associated with the excitation of surface polaritons. These new features arise when the factorization approximation is not made in calculating the correlation function C .

Angular correlation functions of light scattered from weakly rough metal surfaces

“…9͑d͒, but these are not present. Another is C (3) , which predicts a correlation distributed throughout the entire speckle pattern, 15,16 yet we find no such effects. Using a narrower illumination region, which may make such correlations stronger, is impractical for us due to alignment difficulties.…”

“…Both of these correlations are of the short-range type, arising as delta functions in q and k. Indeed, the approach taken here has appar-ently excluded all long-range correlations; these have strengths proportional to the inverse of the illumination width 15,16 and should thus be absent in the limit taken here. Still, our assumption of plane-wave illumination differs from the Gaussian beam of the experiments, but the consequences of such differences should be small.…”

“…For weakly rough surfaces, this question has been addressed through theoretical study of the angular correlation functions of scattered amplitude, 14 where it was claimed that the same constructive interference producing backscattering enhancement also appears in these correlation functions. Other theoretical works have considered the correlation functions of intensity, [15][16][17] which were found to contain contributions arising from a wide variety of plasmon polariton-related scattering processes. Generally speaking, it was shown that these correlation functions contain much more detailed information about the dominant scattering processes than does the mean diffuse intensity.…”

Speckle correlations around the backscattering direction in the double-passage configuration

“…[5][6][7][8] Recently, an additional short-range correlation C ͑10͒ was predicted; it shows the symmetry of speckles around the specular direction in the far-field scattering from a rough surface. 9,10 Similarly, a theoretical analysis of the symmetry of speckle patterns around the backscattering direction and the motion of the speckles as the source is moved was carried out by Escamilla et al 11 This study was performed to verify the theoretical predictions by Escamilla et al 11 and to explore the extent to which the new phenomena can be realized. In Section 2 the problem is formulated, and in Section 3 the experimental setup is discussed.…”

Phase-coherent elastic scattering of electromagnetic waves from a random array of resonant dielectric ridges on a dielectric substrate: Weak roughness limit

“…[5][6][7][8] It will be shown how these effects, as observed in the speckle correlation functions for the light scattered from rough surfaces, [15][16][17][18][19][20] can be enhanced by the resonant properties ͑frequency resonances͒ of dielectric materials forming the surface. [21][22][23][24] Results will be presented for spe-cific systems that can be experimentally realized.…”