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The speckle correlations in the light scattered from a volume disordered dielectric medium are studied theoretically. A scalar wave treatment is used for the motion of the light in the system, and the dielectric constant of the volume disordered medium is taken to be of the form (epsilon) (vector r) equals (epsilon) ((omega) ) plus (delta) (epsilon) (vector r), where (epsilon) ((omega) ) is a homogeneous isotropic frequency- dependent dielectric constant and (delta) (epsilon) (vector r) is a zero-mean Gaussian random process. A diagrammatic perturbation theory approach is used to compute the speckle correlation function defined by C(vector q, vector kvector q', vector k') equals <{I(vector qvector k) - [I(vector qvector k)]} {I(vector q'vector k') - [I(vector q'vector k')]}> where I(vector qvector k) is proportional to the differential scattering coefficient for the elastic scattering of light of incident wavevector vector k into light of wavevector vector q. Contributions associated with ladder, maximally crossed, and more complicated higher order diagrams are summed in the determination of the speckle correlation function. In addition we make the approximation of including only s- scattering in the evaluation of the various diagrams contributing to the speckle correlation function. Results are presented for C(vector q, vector kvector q', vector k') in the approximation C equals C(1) plus C(10) plus C(1.5) where C(1), C(10) and C(1.5) are terms arising from three distinct classes of diagrams. The contribution C(1), which contains the memory and time-reversed memory effect terms, has been studied before and is proportional to (delta) (vector q minus vector k minus vector q' plus vector k'). C(10) is a new term (of the same order of magnitude as C(1)) in the scattering of light from volume disorder which is found to be proportional to (delta) (vector q minus vector k plus vector q' minus vector k'). C(1.5) is a new term in the scattering of light from volume disorder which exhibits an unrestricted dependence on vector q, vector k, vector q', vector k' and a series of interesting intensity peaks related to the resonant scattering of light by the volume disorder. The contributions C(10) and C(1.5) have been considered in the study of the speckle correlation function for the scattering of light from rough surfaces, but this is the first consideration of these terms in the scattering of light from volume disorder.
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