Light scattering from isolated stacking faults in natural diamond

Abstract

Abstract The specular reflection of a focused beam of laser light (λ = 632·8nm) from isolated stacking faults parallel to {111} in a natural type-I diamond is described. The intensity of the reflected beam is 5·7 × 10−8 times that of the incident beam. From measurements of scattered light intensity as functions of analyser orientation and polarization direction of the incident beam, the Jones matrix for reflection was deduced to be diagonal. Theoretical evaluation of this Jones matrix was carried out on the basis of the Fresnel formulae for reflection, assuming a discontinuous change in reflective index between the stacking fault volume and the surrounding diamond matrix. In this calculation the optical indicatrix in the stacking fault region was assumed to be uniaxial with its optic axis normal to the defect plane. Application of the Rayleigh-Gans theory for light scattering, assuming a continuous change in refractivity, showed that the observed specular reflection is characteristic for planar faults whi...