Utilisation des franges d'interference en lumiere diffuse pour l'etude de l'etat de surface d'un diffuseur

Digital laser speckle spectral correlation within the framework of the Fresnel approximation of the scalar Kirchhoff theory and its application in surface roughness measurement

“…It is similar to the condition published in [6], but it contains also the dependence on the angle . It is obvious that we can influence the range of measurable values of by proper choice of wavelengths l,l l and the angle of incidence (observation) .…”

“…This condition is necessary to ensure a non-zero correlation term in the equation (10). The relation (11) corresponds to that derived in [5,6]. But the condition (11) determines the periodicity of the Young's fringes simultaneously.…”

“…This problem (angle speckle correlation) has been solved in [1][2][3][4]. Another possibility is to employ the spectral speckle correlation [5][6][7][8][9][10][11][12][13][14][15][16], that is, determine a relation between statistical parameters of the surface under study and the correlation of two laser speckle fields obtained with two primary laser waves of different wavelengths scattered from the same area of the surface. The angle of incidence on the surface is the same for those two waves.…”